Toshiba TV29C90 problem; Image fades to black...

[N_Cook]

Sam Goldwasser <sam@plus.seas.upenn.edu> wrote in message
news:6wve1ae5t7.fsf@plus.seas.upenn.edu...

This is a (now obsolete I assume) 64/256 1+ GHz prescaler in a 14 pin DIP.

Any leads other than what Google turns up for places that will take
an arm, leg, and your first and second born in exchange for locating
a 100,000 of them and probably won't return email about quantity 1.

Thanks!

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above
is
ignored unless my full name AND either lasers or electronics is included
in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

Data including full die schematic in 1986 RCA databook

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

 

[N_Cook]

Sam Goldwasser <sam@plus.seas.upenn.edu> wrote in message
news:6wve1ae5t7.fsf@plus.seas.upenn.edu...

This is a (now obsolete I assume) 64/256 1+ GHz prescaler in a 14 pin DIP.

Any leads other than what Google turns up for places that will take
an arm, leg, and your first and second born in exchange for locating
a 100,000 of them and probably won't return email about quantity 1.

Thanks!

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above
is
ignored unless my full name AND either lasers or electronics is included
in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

Data including full die schematic in 1986 RCA databook

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

 

[N_Cook]

Sam Goldwasser <sam@plus.seas.upenn.edu> wrote in message
news:6wve1ae5t7.fsf@plus.seas.upenn.edu...

This is a (now obsolete I assume) 64/256 1+ GHz prescaler in a 14 pin DIP.

Any leads other than what Google turns up for places that will take
an arm, leg, and your first and second born in exchange for locating
a 100,000 of them and probably won't return email about quantity 1.

Thanks!

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above
is
ignored unless my full name AND either lasers or electronics is included
in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

CA3163 may be pin for pin the same but only up to 1000M


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

 

[N_Cook]

Sam Goldwasser <sam@plus.seas.upenn.edu> wrote in message
news:6wve1ae5t7.fsf@plus.seas.upenn.edu...

This is a (now obsolete I assume) 64/256 1+ GHz prescaler in a 14 pin DIP.

Any leads other than what Google turns up for places that will take
an arm, leg, and your first and second born in exchange for locating
a 100,000 of them and probably won't return email about quantity 1.

Thanks!

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above
is
ignored unless my full name AND either lasers or electronics is included
in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

CA3163 may be pin for pin the same but only up to 1000M


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

 

[bz]

"Dave Plowman (News)" <dave@davenoise.co.uk> wrote in
news:4fa14a16d7dave@davenoise.co.uk:

In article <Xns9AA1BC2E27A24WQAHBGMXSZHVspammote@130.39.198.139>,
bz <bz+ser@ch100-5.chem.lsu.edu> wrote:
This means that you can regulate the 'open circuit voltage'. You would
want to make sure that never exceeds your battery voltage by more than
a few percent.

IMHO the charge voltage is pretty irrelevant. It's the current that
matters.

Here is a current regulator that can be used for 0-2A with supplies that
don't have current regulation built in.
http://kd1jv.qrpradio.com/vps/voclps.HTM





--
bz

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

bz+spr@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

 

[bz]

"Dave Plowman (News)" <dave@davenoise.co.uk> wrote in
news:4fa14a16d7dave@davenoise.co.uk:

In article <Xns9AA1BC2E27A24WQAHBGMXSZHVspammote@130.39.198.139>,
bz <bz+ser@ch100-5.chem.lsu.edu> wrote:
This means that you can regulate the 'open circuit voltage'. You would
want to make sure that never exceeds your battery voltage by more than
a few percent.

IMHO the charge voltage is pretty irrelevant. It's the current that
matters.

Here is a current regulator that can be used for 0-2A with supplies that
don't have current regulation built in.
http://kd1jv.qrpradio.com/vps/voclps.HTM





--
bz

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

bz+spr@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

 

[N_Cook]

Sam Goldwasser <sam@plus.seas.upenn.edu> wrote in message
news:6wmymlev8z.fsf_-_@plus.seas.upenn.edu...

"N_Cook" <diverse@tcp.co.uk> writes:

Sam Goldwasser <sam@plus.seas.upenn.edu> wrote in message
news:6wve1ae5t7.fsf@plus.seas.upenn.edu...
This is a (now obsolete I assume) 64/256 1+ GHz prescaler in a 14 pin
DIP.

Any leads other than what Google turns up for places that will take
an arm, leg, and your first and second born in exchange for locating
a 100,000 of them and probably won't return email about quantity 1.

Thanks!

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/

Data including full die schematic in 1986 RCA databook

Yep, have that (or equivalent):

http://repairfaq.cis.upenn.edu/Misc/ct125/CA3179G.pdf

Had to twist Google's arm to get that.

This is in reference to the Ramsey CT-125 frequency counter I asked
about in another thread.

The CA3179G may be working fine but tends to oscillate if there is no or
low
input, or the input frequency is below about 2 MHz. Someone else with
the same counter described a similar behavior so it may simply be normal
for the chip, or the mediocre design and layout of the counter PCB.

But the sensitivity of the input is also way too low (requires about 1 V,
spec calls for a few dozen mV), so this could be related to the prescaler,
or to the input transistor, though that seems to work.

The CA3179G is socketed so it would be nice to be able to simply swap in
another one to see if anything changes. (Yes, I know, a socketed part in
a GHz circuit isn't the greatest, but the wet finger test doesn't turn
up any obvious effects).

I have a directory with the Ramsey info including schematics (thanks to
someone on this NG):

http://repairfaq.cis.upenn.edu/Misc/ct125/

I don't guarantee this link will remain forever, so get'em while you can!

Thanks.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above
is
ignored unless my full name AND either lasers or electronics is included
in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

Can you be sure the socket is original?

Datasheet shows Smith chart and (quasi?) microstrip layout and certainly no
socket.
How about removing the socket and minimally soldering IC to board and see
what happens.
3 pins are n/c anyway

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

 

[N_Cook]

Sam Goldwasser <sam@plus.seas.upenn.edu> wrote in message
news:6wmymlev8z.fsf_-_@plus.seas.upenn.edu...

"N_Cook" <diverse@tcp.co.uk> writes:

Sam Goldwasser <sam@plus.seas.upenn.edu> wrote in message
news:6wve1ae5t7.fsf@plus.seas.upenn.edu...
This is a (now obsolete I assume) 64/256 1+ GHz prescaler in a 14 pin
DIP.

Any leads other than what Google turns up for places that will take
an arm, leg, and your first and second born in exchange for locating
a 100,000 of them and probably won't return email about quantity 1.

Thanks!

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/

Data including full die schematic in 1986 RCA databook

Yep, have that (or equivalent):

http://repairfaq.cis.upenn.edu/Misc/ct125/CA3179G.pdf

Had to twist Google's arm to get that.

This is in reference to the Ramsey CT-125 frequency counter I asked
about in another thread.

The CA3179G may be working fine but tends to oscillate if there is no or
low
input, or the input frequency is below about 2 MHz. Someone else with
the same counter described a similar behavior so it may simply be normal
for the chip, or the mediocre design and layout of the counter PCB.

But the sensitivity of the input is also way too low (requires about 1 V,
spec calls for a few dozen mV), so this could be related to the prescaler,
or to the input transistor, though that seems to work.

The CA3179G is socketed so it would be nice to be able to simply swap in
another one to see if anything changes. (Yes, I know, a socketed part in
a GHz circuit isn't the greatest, but the wet finger test doesn't turn
up any obvious effects).

I have a directory with the Ramsey info including schematics (thanks to
someone on this NG):

http://repairfaq.cis.upenn.edu/Misc/ct125/

I don't guarantee this link will remain forever, so get'em while you can!

Thanks.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above
is
ignored unless my full name AND either lasers or electronics is included
in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

Can you be sure the socket is original?

Datasheet shows Smith chart and (quasi?) microstrip layout and certainly no
socket.
How about removing the socket and minimally soldering IC to board and see
what happens.
3 pins are n/c anyway

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

 

[N_Cook]

John Vallelunga <johnv@sonic.net> wrote in message
news:48323f09$0$34483$742ec2ed@news.sonic.net...

NoSp wrote:
My laptop's display backlight has been fading since I bought it a few
years ago, so I think it's about time I exchange the CCFL backlight
with a new one. The LCD in question is a Samsung LTN152W6-L01.

I've been trying to follow the instructions at sites such as
lcdparts.net, but there aren't any instructions for my particular LCD.
I've never disassembled an LCD before, so I'm a little worried that
I'll do something wrong.
Here are a couple of photos I've taken of my LCD:

http://img212.imageshack.us/my.php?image=samsung1sr9.jpg
http://img88.imageshack.us/my.php?image=samsung2gc1.jpg

There's a warning at the top saying I shouldn't touch the white tape.
Does this mean the white tape shouldn't be *removed*?
I've read somewhere that if you apply pressure unevenly to the LCD
panel you'll get lines and other abnomalities in the display (I assume
the white tape has been applied for even pressure all across the LCD
panel).

The problem is that it seems (at least according to what I've read
online) that I need to remove the metal frame around the LCD panel in
order to expose the CCFL backlight -is this correct?
Unfortunately the white tape extends beyond the metal frame, so if I
shouldn't remove it what do I do?

The second photo shows the metal bracket removed. It's the only one I
could remove without removing the white tape as well, and the
backlight is found underneath. Is there a neat way to remove the CCFL
without removing the whole frame?
Here is my story:
A few weeks ago the backlight on my wife's Dell 700m laptop would go out
after a minute or so. Research indicated that replacing the tube might
solve this (and this info turned out to be correct). Since I have
worked in microelectronics for 30+ years I thought I would try it.
I had an old display that I took apart for practice and that one was
very simple. The tube just slid out the side; no skills necessary! The
laptop display was very different. Nothing went according to plan and
everything was just too small , too fragile, and too precise. Yes I
read those same instructions but they are too generic. And dealing with
a 10 inch tube that is only 2mm in diameter is scary; I recommend you
order at least two!
Anyhow, after much frustration I managed to successfully replace the
tube and it now lights up properly. There were only two problems.
Somehow I managed to crack the corner of the display making it useless.
See this photo: http://www.sonic.net/johnv/ebay/700mscreen.jpg
Even ignoring this, the bottom of the display is no longer of uniform
brightness. We probably could have lived with this but be forewarned
that the same thing could happen to you. This repair may be best left
to the experts. I will never try this again on a laptop. Fortunately
newer laptops now are beginning to use LED backlights....like the one my
wife had to buy to replace her 700m. The CCFL should be obsolete in
about 3-5 years.

Good luck!

To prevent such a crack do you think such displays need a temporary scaffold
somehow attached to them while doing such work?
I'm assuming the damage was done just by holding between thumb and finger at
the corners.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

 

[N_Cook]

John Vallelunga <johnv@sonic.net> wrote in message
news:48323f09$0$34483$742ec2ed@news.sonic.net...

NoSp wrote:
My laptop's display backlight has been fading since I bought it a few
years ago, so I think it's about time I exchange the CCFL backlight
with a new one. The LCD in question is a Samsung LTN152W6-L01.

I've been trying to follow the instructions at sites such as
lcdparts.net, but there aren't any instructions for my particular LCD.
I've never disassembled an LCD before, so I'm a little worried that
I'll do something wrong.
Here are a couple of photos I've taken of my LCD:

http://img212.imageshack.us/my.php?image=samsung1sr9.jpg
http://img88.imageshack.us/my.php?image=samsung2gc1.jpg

There's a warning at the top saying I shouldn't touch the white tape.
Does this mean the white tape shouldn't be *removed*?
I've read somewhere that if you apply pressure unevenly to the LCD
panel you'll get lines and other abnomalities in the display (I assume
the white tape has been applied for even pressure all across the LCD
panel).

The problem is that it seems (at least according to what I've read
online) that I need to remove the metal frame around the LCD panel in
order to expose the CCFL backlight -is this correct?
Unfortunately the white tape extends beyond the metal frame, so if I
shouldn't remove it what do I do?

The second photo shows the metal bracket removed. It's the only one I
could remove without removing the white tape as well, and the
backlight is found underneath. Is there a neat way to remove the CCFL
without removing the whole frame?
Here is my story:
A few weeks ago the backlight on my wife's Dell 700m laptop would go out
after a minute or so. Research indicated that replacing the tube might
solve this (and this info turned out to be correct). Since I have
worked in microelectronics for 30+ years I thought I would try it.
I had an old display that I took apart for practice and that one was
very simple. The tube just slid out the side; no skills necessary! The
laptop display was very different. Nothing went according to plan and
everything was just too small , too fragile, and too precise. Yes I
read those same instructions but they are too generic. And dealing with
a 10 inch tube that is only 2mm in diameter is scary; I recommend you
order at least two!
Anyhow, after much frustration I managed to successfully replace the
tube and it now lights up properly. There were only two problems.
Somehow I managed to crack the corner of the display making it useless.
See this photo: http://www.sonic.net/johnv/ebay/700mscreen.jpg
Even ignoring this, the bottom of the display is no longer of uniform
brightness. We probably could have lived with this but be forewarned
that the same thing could happen to you. This repair may be best left
to the experts. I will never try this again on a laptop. Fortunately
newer laptops now are beginning to use LED backlights....like the one my
wife had to buy to replace her 700m. The CCFL should be obsolete in
about 3-5 years.

Good luck!

To prevent such a crack do you think such displays need a temporary scaffold
somehow attached to them while doing such work?
I'm assuming the damage was done just by holding between thumb and finger at
the corners.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

 

[GregS]

In article <p7ednbcf8_qQTK_VnZ2dnUVZ_ozinZ2d@kans.com>, Brian <standingwaterDELETETHIS@networksplus.net> wrote:

clifto wrote:
Brian wrote:
clifto wrote:
I buy through local alarm companies. Call two or three and at least one
will
sell over the counter.
Just got 'em (via eBay) -- "Rhino" brand; about US$16 each, including
shipping. Look good, and hopefully will work well! Best retail price I
saw, plus shipping, was about $32 each.

I'll check next time. My last set was local and in between those prices.


Good! There's only one batteries-only dealer here in town, and it is
about a 15 mile round trip. So add ~$3 for gas ...

Installed the new batteries yesterday. As warned, the lugs were
smaller, so I had to crimp-down one connector slightly to get a tighter fit.

Also, the last connection was shocking! Actually sparking -- one huge
bolt, and I'm glad I wasn't in its way. There's a good-sized capacitor
internally to the UPS, and my guess is that the batteries needed to
recharge it upon connection.

The UPS then worked normally! So yes, as the early responders answered,
it was simply dead batteries. Will recycle the old ones, and keep the
UPS plugged-in continuously so that hopefully these new batteries will
last a long time.

I just replaced the batteries in a non responding SMART UPS. What a stupid UPS.
The batteies were for a 1500 watt unit, heavy.

greg

 

[GregS]

In article <p7ednbcf8_qQTK_VnZ2dnUVZ_ozinZ2d@kans.com>, Brian <standingwaterDELETETHIS@networksplus.net> wrote:

clifto wrote:
Brian wrote:
clifto wrote:
I buy through local alarm companies. Call two or three and at least one
will
sell over the counter.
Just got 'em (via eBay) -- "Rhino" brand; about US$16 each, including
shipping. Look good, and hopefully will work well! Best retail price I
saw, plus shipping, was about $32 each.

I'll check next time. My last set was local and in between those prices.


Good! There's only one batteries-only dealer here in town, and it is
about a 15 mile round trip. So add ~$3 for gas ...

Installed the new batteries yesterday. As warned, the lugs were
smaller, so I had to crimp-down one connector slightly to get a tighter fit.

Also, the last connection was shocking! Actually sparking -- one huge
bolt, and I'm glad I wasn't in its way. There's a good-sized capacitor
internally to the UPS, and my guess is that the batteries needed to
recharge it upon connection.

The UPS then worked normally! So yes, as the early responders answered,
it was simply dead batteries. Will recycle the old ones, and keep the
UPS plugged-in continuously so that hopefully these new batteries will
last a long time.

I just replaced the batteries in a non responding SMART UPS. What a stupid UPS.
The batteies were for a 1500 watt unit, heavy.

greg

 

[dBc]

Greetings..

Regarding:
"Since I have worked in microelectronics for 30+ years I thought I
would try it."
"And dealing with a 10 inch tube that is only 2mm in diameter is
scary; I recommend you order at least two!"
..
..
"...This repair may be best left to the experts. I will never try
this again on a laptop."

There's a moral to that story..

Cheers,
Mr. Mentor



"John Vallelunga" <johnv@sonic.net> wrote in message
news:48323f09$0$34483$742ec2ed@news.sonic.net...
| NoSp wrote:
| > My laptop's display backlight has been fading since I bought it a
few
| > years ago, so I think it's about time I exchange the CCFL
backlight
| > with a new one. The LCD in question is a Samsung LTN152W6-L01.
| >
| > I've been trying to follow the instructions at sites such as
| > lcdparts.net, but there aren't any instructions for my particular
LCD.
| > I've never disassembled an LCD before, so I'm a little worried
that
| > I'll do something wrong.
| > Here are a couple of photos I've taken of my LCD:
| >
| > http://img212.imageshack.us/my.php?image=samsung1sr9.jpg
| > http://img88.imageshack.us/my.php?image=samsung2gc1.jpg
| >
| > There's a warning at the top saying I shouldn't touch the white
tape.
| > Does this mean the white tape shouldn't be *removed*?
| > I've read somewhere that if you apply pressure unevenly to the LCD
| > panel you'll get lines and other abnomalities in the display (I
assume
| > the white tape has been applied for even pressure all across the
LCD
| > panel).
| >
| > The problem is that it seems (at least according to what I've read
| > online) that I need to remove the metal frame around the LCD panel
in
| > order to expose the CCFL backlight -is this correct?
| > Unfortunately the white tape extends beyond the metal frame, so if
I
| > shouldn't remove it what do I do?
| >
| > The second photo shows the metal bracket removed. It's the only
one I
| > could remove without removing the white tape as well, and the
| > backlight is found underneath. Is there a neat way to remove the
CCFL
| > without removing the whole frame?
| Here is my story:
| A few weeks ago the backlight on my wife's Dell 700m laptop would go
out
| after a minute or so. Research indicated that replacing the tube
might
| solve this (and this info turned out to be correct). Since I have
| worked in microelectronics for 30+ years I thought I would try it.
| I had an old display that I took apart for practice and that one was
| very simple. The tube just slid out the side; no skills necessary!
The
| laptop display was very different. Nothing went according to plan
and
| everything was just too small , too fragile, and too precise. Yes I
| read those same instructions but they are too generic. And dealing
with
| a 10 inch tube that is only 2mm in diameter is scary; I recommend
you
| order at least two!
| Anyhow, after much frustration I managed to successfully replace the
| tube and it now lights up properly. There were only two problems.
| Somehow I managed to crack the corner of the display making it
useless.
| See this photo: http://www.sonic.net/johnv/ebay/700mscreen.jpg
| Even ignoring this, the bottom of the display is no longer of
uniform
| brightness. We probably could have lived with this but be
forewarned
| that the same thing could happen to you. This repair may be best
left
| to the experts. I will never try this again on a laptop.
Fortunately
| newer laptops now are beginning to use LED backlights....like the
one my
| wife had to buy to replace her 700m. The CCFL should be obsolete in
| about 3-5 years.
|
| Good luck!

 

[dBc]

Greetings Olivia & others..

First of all, what kind of test equipment do you have use of? Do you
know how to use it? If not, you're going to need to find someone that
IS familiar with anything from a DVM (Digital Volt Meter) to,
ultimately, an oscilloscope and has use of them.

Regarding:
"There appeared to be only one burnt out component and I replaced it
but it still doesn't work."
What specific component was that? Further, does it relate to the
schematic of the .pdf file referenced?

"I'm pretty certain that this is a copy of the Boss TR-2 because the
schematic seems to fit with the exception of the IC chips."

"It did look like something was spilled inside the pedal and I've
cleaned that out."
Any idea what was spilled in it? Was it sticky? If it was something
like a soft drink that has sat for some time without being cleaned
out, there's a good chance that the potentiometers may also need to be
replaced in spite of a electronic component failure. I've had such
experience fixing a fellow radio amateur's HF radio where his daughter
spilled Coke all over the front of the radio. It was a mess and a good
deal of labor to resurrect the front panel alone, not to mention the
rest of the radio!

=== === === ===

It would probably be a good idea to actually get the schematic to the
piece of electronics that you've got. Writing Johnson may provide
this, request a service manual -
http://www.johnsongtr.com/Fifties_Tremolo.888.0.html. At the very
least, explain that a schematic would be immensely helpful. Expressing
the interest to order parts for your unit may show the need they need
to hear about. IF they won't provide the schematic, ask them how they
propose that you order new components that you suspect you'll need?
Don't be surprised that the units are produced over in China and
aren't serviced, per se', but entire boards removed and replaced.
China has revealed a 'throw away' society of electronics like none
we've ever seen before. Meanwhile, in your local area wherever that
may be, a substantial hourly rate to merely swapping one board with
another.

Keeping in mind that this REALLY isn't the correct schematic for the
unit you have, in order to resolve this, you're going to first need to
verify that you've got B+ to the electronics. The power supply circuit
is at the bottom of the schematic above AC ADAPTOR. Namely +9V, +5.5V
& +4.5V DC should be verified to exist. NOTE: Depending on what was
burnt out will also dictate where one should also be looking. If any
of these biases are missing, they will have to be fixed before you can
do any further diagnosis!

Next, with the above voltages present, turn OFF any and all special
effects and apply a signal into the input and follow it through with
either a DVM or, ultimately, an oscilloscope towards the output.
Incidentally, that signal path initially passes through R15, C8 to the
source of FET transistor Q4. Continue to follow that signal towards
the output through either the IC1B, IC2A, Q1 or the Q3 path all
leading to the positive lead of C1 (1uF/50V). Finally through Q2's
base to the emitter and through C2 & R1 to the output.

If you lose the input signal anywhere along this path, back up to the
component or region where that signal will not pass and verify that
the signal exists on one side but not the other. Attempt to isolate to
your suspect component. Verify correct DC bias to the component, if
it's still not passing a signal, that will be the component to
replace.

As you get the direct (non-effect) path for the pedal to work, then
you can look into the individual circuits for the Rate, Wave and Depth
effects according to the picture at the above URL. By using the same
method of tracing a signal from the input of the effect electronics
through towards the output of that circuit, one by one, you'll verify
each subsection of the circuit.

Trying to learn all of what you need in a Use-group reply or two is
usually not adequate. Again, having someone that is versed in
electronics theory, diagnosis and repair that either has use of or
owns their own test equipment will substantially reduce the amount of
effort and time you'll end up dedicating for, essentially, a $60/USD
piece of electronics.

Good luck!

Cheers,
Mr. Mentor




<smallfloralprint@gmail.com> wrote in message
news:4a47c4d6-6e0a-4a89-959b-28a8a3431d35@f36g2000hsa.googlegroups.com...
| I'm trying to repair this pedal for a friend. There appeared to be
| only one burnt out component and I replaced it but it still doesn't
| work. It did look like something was spilled inside the pedal and
I've
| cleaned that out. When in bypass, the signal passing through is
| distorted and garbled, like hearing it on a faint radio station. But
| when the pedal is engaged, it doesn't pass signal at all. I'm pretty
| certain that this is a copy of the Boss TR-2 because the schematic
| seems to fit with the exception of the IC chips.
| http://www.schematicheaven.com/effects/boss_tr2_tremolo.pdf
| Since the "bypass/engage mode" is triggered by a momentary switch,
and
| the dry signal goes down a very processed chain of components, I
| haven't been able to figure it out. What typically goes bad when
there
| are spills? From looking at this schematic, how would I go about
| figuring out where in the "dry signal" chain things are wrong?
|
| Thank you very much!
|
| Olivia

 

[dBc]

Greetings Olivia & others..

First of all, what kind of test equipment do you have use of? Do you
know how to use it? If not, you're going to need to find someone that
IS familiar with anything from a DVM (Digital Volt Meter) to,
ultimately, an oscilloscope and has use of them.

Regarding:
"There appeared to be only one burnt out component and I replaced it
but it still doesn't work."
What specific component was that? Further, does it relate to the
schematic of the .pdf file referenced?

"I'm pretty certain that this is a copy of the Boss TR-2 because the
schematic seems to fit with the exception of the IC chips."

"It did look like something was spilled inside the pedal and I've
cleaned that out."
Any idea what was spilled in it? Was it sticky? If it was something
like a soft drink that has sat for some time without being cleaned
out, there's a good chance that the potentiometers may also need to be
replaced in spite of a electronic component failure. I've had such
experience fixing a fellow radio amateur's HF radio where his daughter
spilled Coke all over the front of the radio. It was a mess and a good
deal of labor to resurrect the front panel alone, not to mention the
rest of the radio!

=== === === ===

It would probably be a good idea to actually get the schematic to the
piece of electronics that you've got. Writing Johnson may provide
this, request a service manual -
http://www.johnsongtr.com/Fifties_Tremolo.888.0.html. At the very
least, explain that a schematic would be immensely helpful. Expressing
the interest to order parts for your unit may show the need they need
to hear about. IF they won't provide the schematic, ask them how they
propose that you order new components that you suspect you'll need?
Don't be surprised that the units are produced over in China and
aren't serviced, per se', but entire boards removed and replaced.
China has revealed a 'throw away' society of electronics like none
we've ever seen before. Meanwhile, in your local area wherever that
may be, a substantial hourly rate to merely swapping one board with
another.

Keeping in mind that this REALLY isn't the correct schematic for the
unit you have, in order to resolve this, you're going to first need to
verify that you've got B+ to the electronics. The power supply circuit
is at the bottom of the schematic above AC ADAPTOR. Namely +9V, +5.5V
& +4.5V DC should be verified to exist. NOTE: Depending on what was
burnt out will also dictate where one should also be looking. If any
of these biases are missing, they will have to be fixed before you can
do any further diagnosis!

Next, with the above voltages present, turn OFF any and all special
effects and apply a signal into the input and follow it through with
either a DVM or, ultimately, an oscilloscope towards the output.
Incidentally, that signal path initially passes through R15, C8 to the
source of FET transistor Q4. Continue to follow that signal towards
the output through either the IC1B, IC2A, Q1 or the Q3 path all
leading to the positive lead of C1 (1uF/50V). Finally through Q2's
base to the emitter and through C2 & R1 to the output.

If you lose the input signal anywhere along this path, back up to the
component or region where that signal will not pass and verify that
the signal exists on one side but not the other. Attempt to isolate to
your suspect component. Verify correct DC bias to the component, if
it's still not passing a signal, that will be the component to
replace.

As you get the direct (non-effect) path for the pedal to work, then
you can look into the individual circuits for the Rate, Wave and Depth
effects according to the picture at the above URL. By using the same
method of tracing a signal from the input of the effect electronics
through towards the output of that circuit, one by one, you'll verify
each subsection of the circuit.

Trying to learn all of what you need in a Use-group reply or two is
usually not adequate. Again, having someone that is versed in
electronics theory, diagnosis and repair that either has use of or
owns their own test equipment will substantially reduce the amount of
effort and time you'll end up dedicating for, essentially, a $60/USD
piece of electronics.

Good luck!

Cheers,
Mr. Mentor




<smallfloralprint@gmail.com> wrote in message
news:4a47c4d6-6e0a-4a89-959b-28a8a3431d35@f36g2000hsa.googlegroups.com...
| I'm trying to repair this pedal for a friend. There appeared to be
| only one burnt out component and I replaced it but it still doesn't
| work. It did look like something was spilled inside the pedal and
I've
| cleaned that out. When in bypass, the signal passing through is
| distorted and garbled, like hearing it on a faint radio station. But
| when the pedal is engaged, it doesn't pass signal at all. I'm pretty
| certain that this is a copy of the Boss TR-2 because the schematic
| seems to fit with the exception of the IC chips.
| http://www.schematicheaven.com/effects/boss_tr2_tremolo.pdf
| Since the "bypass/engage mode" is triggered by a momentary switch,
and
| the dry signal goes down a very processed chain of components, I
| haven't been able to figure it out. What typically goes bad when
there
| are spills? From looking at this schematic, how would I go about
| figuring out where in the "dry signal" chain things are wrong?
|
| Thank you very much!
|
| Olivia

 

[dBc]

Greetings..

Regarding:
"| Doorbell transformers are often located in the attic."

True! Also, all too often all but forgotten about as they create RFI
havoc for nearby radio amateurs / SWL etc.! Trying to get the neighbor
or business to be cooperative to replace this crude RF transmitter
can, and often IS, quite a challenge!

Usually brought to you by the sheer ignorance of a fellow home or
business owner that "didn't know" such things could ever happen..

Cheers,
Mr. Mentor



"bz" <bz+ser@ch100-5.chem.lsu.edu> wrote in message
news:Xns9A9DC1EFF530EWQAHBGMXSZHVspammote@130.39.198.139...
| dave@hurtle.com wrote in news:0c3c37fc-f6f1-4f44-9b9e-a93cdb18f78b@
| 27g2000hsf.googlegroups.com:
|
| > OK. I popped the cover off the control panel outside to have a
look.
| > At some point the control module was replaced with a Lee Dan
PK-543.
| > Well it looks like they still make them if this is the problem.
The
| > only other possible problem could be the transformer which kicks
the
| > voltage down to 16 VAC to run the module.
| >
| > Now here's a dumb question. Where would this transformer be
located?
| > It's not behind the control panel outside. I looked around the
| > basement by the circuit breakers/cable/phone lines and couldn't
find
| > it there either. Any suggestions where to look?
|
| Doorbell transformers are often located in the attic.
|
|
|
|
|
|
|
| --
| bz 73 de N5BZ k
|
| please pardon my infinite ignorance, the set-of-things-I-do-not-know
is an
| infinite set.
|
| bz+ser@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

 

[dBc]

Greetings..

Regarding:
"| Doorbell transformers are often located in the attic."

True! Also, all too often all but forgotten about as they create RFI
havoc for nearby radio amateurs / SWL etc.! Trying to get the neighbor
or business to be cooperative to replace this crude RF transmitter
can, and often IS, quite a challenge!

Usually brought to you by the sheer ignorance of a fellow home or
business owner that "didn't know" such things could ever happen..

Cheers,
Mr. Mentor



"bz" <bz+ser@ch100-5.chem.lsu.edu> wrote in message
news:Xns9A9DC1EFF530EWQAHBGMXSZHVspammote@130.39.198.139...
| dave@hurtle.com wrote in news:0c3c37fc-f6f1-4f44-9b9e-a93cdb18f78b@
| 27g2000hsf.googlegroups.com:
|
| > OK. I popped the cover off the control panel outside to have a
look.
| > At some point the control module was replaced with a Lee Dan
PK-543.
| > Well it looks like they still make them if this is the problem.
The
| > only other possible problem could be the transformer which kicks
the
| > voltage down to 16 VAC to run the module.
| >
| > Now here's a dumb question. Where would this transformer be
located?
| > It's not behind the control panel outside. I looked around the
| > basement by the circuit breakers/cable/phone lines and couldn't
find
| > it there either. Any suggestions where to look?
|
| Doorbell transformers are often located in the attic.
|
|
|
|
|
|
|
| --
| bz 73 de N5BZ k
|
| please pardon my infinite ignorance, the set-of-things-I-do-not-know
is an
| infinite set.
|
| bz+ser@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

 

[Allodoxaphobia]

On Tue, 20 May 2008 19:03:57 -0400, Michael A. Terrell wrote:

James Sweet wrote:

Is that legal?

Mine is on the wall in the garage, I've also seen them in closets, never
seen one in the attic.

Most of the ones I've seen are on the side of a breaker box or fuse
box. Some mounted right to the box, while others are on a 4" square
plate and mounted to a square steel box for fire safety.

Every one I've ever encountered in the last 40 years around Colorado
have been mounted on a rafter in the attic.

But, I'm also sure that the hodge-podge of electrical codes across the
U.S.A. could dictate that it be mounted almost ANYWHERE.

Jonesy
--
Marvin L Jones | jonz | W3DHJ | linux
38.24N 104.55W | @ config.com | Jonesy | OS/2
*** Killfiling google posts: <http://jonz.net/ng.htm>

 

[Arfa Daily]

"Robert Swinney" <judybob@tx.rr.com> wrote in message
news:4832d9e5$0$20189$4c368faf@roadrunner.com...

My 3 or 4 year-old 27 in. Sony went belly up. I've replaced it with a
digi-ready Samsung and am
thinking
about repairing the Sony and relegating it to the bedroom. Sony symptoms
seem to indicate the video
processor is at fault; ragged, torn but identifyable B&W pix;
picture-in-picture is OK and in color.
In my opinion, these symptoms are consistent with a failed video
processor. Does anyone have
experience replacing the video processor in a Sony TV ? Is it a SM chip,
etc, etc. Please advise,
Thanx.

Bob Swinney

In general, chips pretty much work, or don't. It's rare to get the sort of
fault that you're describing from any kind of semiconductor failure. My
money would be on caps.

Arfa

 

[Arfa Daily]

"GregS" <zekfrivo@zekfrivolous.com> wrote in message
news:g0uvro$ee2$1@usenet01.srv.cis.pitt.edu...

In article <p7ednbcf8_qQTK_VnZ2dnUVZ_ozinZ2d@kans.com>, Brian
standingwaterDELETETHIS@networksplus.net> wrote:
clifto wrote:
Brian wrote:
clifto wrote:
I buy through local alarm companies. Call two or three and at least
one
will
sell over the counter.
Just got 'em (via eBay) -- "Rhino" brand; about US$16 each, including
shipping. Look good, and hopefully will work well! Best retail price
I
saw, plus shipping, was about $32 each.

I'll check next time. My last set was local and in between those prices.


Good! There's only one batteries-only dealer here in town, and it is
about a 15 mile round trip. So add ~$3 for gas ...

Installed the new batteries yesterday. As warned, the lugs were
smaller, so I had to crimp-down one connector slightly to get a tighter
fit.

Also, the last connection was shocking! Actually sparking -- one huge
bolt, and I'm glad I wasn't in its way. There's a good-sized capacitor
internally to the UPS, and my guess is that the batteries needed to
recharge it upon connection.

The UPS then worked normally! So yes, as the early responders answered,
it was simply dead batteries. Will recycle the old ones, and keep the
UPS plugged-in continuously so that hopefully these new batteries will
last a long time.

I just replaced the batteries in a non responding SMART UPS. What a stupid
UPS.
The batteies were for a 1500 watt unit, heavy.

greg

I don't think I'm quite following that ...

Arfa