Toshiba TV29C90 problem; Image fades to black...

[Meat Plow]

On Fri, 13 Jun 2008 16:40:41 +0000, PaPaPeng wrote:

On Fri, 13 Jun 2008 03:26:12 -0400, "Michael Kennedy"
Mikek400@remthis.comcast.net> wrote:


"PaPaPeng" <PaPaPeng@yahoo.com> wrote in message
news:jbk354tdtd64bivjsplm9n79ev01vvs1kh@4ax.com...


I have a CRT type SONY 27 inch TV Model KV27T530. It's between 10 to
15 years old and still shows a great sharp picture in excellent color.
I have Cable TV for the basic channels (2 to 13) plus the first tier of
extra channels. A month or so ago it could show only the first tier
channels and would not even display the Channel number for the second
tier. So I took off the back cover to reseat all the connectors.
After that the ON switch wouldn't latch. It comes on and switches
itself off after a few seconds. What should I be looking for to fix
it?

I used to be an electronics tech and had fixed minor TV problems
before. This TV set isn't worth fixing at a shop. I am sure its
basically working OK and I don't like dumping equipment that can be
fixed. I'd be happy if it can just receive the first tier channels.
I've bought a large flat panel TV to watch the coming Olympics. So
fixing the SONY is something I can take my time on to troubleshoot.

Thanks in advance.


So are you saying that there is a mechanical problem with the switch? If
so, just replace the switch.

Or are you saying that the TV shuts down after a few seconds?

Mike



Its not the front panel mechanical switch. I can switch on the TV with
the front panel switch or the remote. There is a distinct click coming
on. Then there is a slight crackle as the static or whatever fires up (to
warm up the CRT?). After around five seconds the TV clicks itself off (as
if there is a safety cutoff.) I looked around for a solenoid like item and
of course there is none. It is something solid state on another part of
the motherboard. The cable runs are so tight I cannot pull the MB out far
enough to see or hear exactly which component is making that noise. If it
is solid state why is there a distinct 'click' then. The question here is
what kind of component makes a click when you use the remote to turn the
TV ON or OFF?

A relay.

As for mis-reconnecting the cable all the cables have keyed connectors and
each of them is unique in size and shape. The cable runs are too tight to
make a mistake running the connector to another pin socket. When I get
around to it I will probably undo all the connectors and reseat them
again.

Make sure all are connected properly.

The other question is, is there such a thing as a hardware problem that
would kill the second tier of cable TV stations? The screen wouldn't
display any channel numbers or programs beyond Ch 13. Just a black screen
and not even the "snow" of a dead station. This condition lasted for a
week. I thought I'd be clever and reseat the connectors to see if that
will fix it. The old 27 inch CRT type TVs are hernia boxes. I am no
longer that young where I can move this thing around easily to fix things.

The tuner is responsible for that.

 

[Jamie]

for what ever reason, I have been looking for a long time now
to buy lets say 5 or more, 3SK291 transistors that are Toshiba made.
this is a dual gate UHF Fet transistor..

Can any one supply a link to a supplier that has this transistor
with out being forced to buy a 1k min etc..

I really only need 1 how ever, I'll buy more just to have them on
hand! They seem to be like gold or something!

This is total bull crap that I can not get this simple part!.

I find nothing but Data sheet after Data sheet. Sights that appear to
have it in the search engine list only to suck you into their sight with
all the spam and then, their search engine yields nothing!.


http://webpages.charter.net/jamie_5"

 

[Franc Zabkar]

On Sat, 14 Jun 2008 03:15:26 -0700 (PDT), "j_slobo@hotmail.com"
<j_slobo@hotmail.com> put finger to keyboard and composed:

Is there some way to detect a 3-5volt say khz clock using an ordinary
instrument(no osciloscope)

If you are asking this question because you need to detect whether the
clock is oscillating, rather than trying to measure its frequency,
then find a buffered logic gate where the clock should be present and
measure the voltage there. If the clock is oscillating, then you
should measure a DC voltage equivalent to half the supply rail.
Depending on the frequency response of your multimeter, the voltage on
the AC range may be 0, so that won't be a good guide. If the clock is
dead, then the gate will be sitting on 0V or close to the positive
supply rail. Of course I'm assuming that the clock is a 50:50 square
wave. BTW, you probably won't get any sensible result measuring the
voltage at, or near, the crystal.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[Jeff Liebermann]

On Sun, 15 Jun 2008 12:53:59 +0800, rebel <me@privacy.net> wrote:

On Sat, 14 Jun 2008 16:49:48 -0700, Jeff Liebermann <jeffl@cruzio.com> wrote:

(snip)

Glue it while it's open.

(snip rest)

The most important bit of all. The solder joint should NOT be expected to
provide the mechanical support for the receptacle - only the electrical bond.

Baloney. Every single laptop I've repaired or inspected, has the
solder leads and circuit board provide the only means of support. A
few provide added protection in the form of a metal cover shield, such
as the HP laptop in the photo:
<http://802.11junk.com/jeffl/pics/HP-laptop/slides/Fried_power_plug.html>
I just ordered some connectors for a Compaq 1692 that also has a metal
shield. The shield helps, but is not that common.

The most disgusting was some ancient laptop, that used a surface mount
power connector with no holes through the board. The other connectors
were attached the same way. They died in a few weeks, or when the
owner tweaked the cords, whichever came first.

Incidentally, I have a pile of 12 laptops waiting for me to spend some
time repairing them. Most have broken power connectors. Some have
butchered power connectors where the owner attempted to repair the
connector. It's a very common problem that would easily be addressed
by a magnetic latch connector (as used by Apple) or mitigated by a
right angle power connector, which would rotate rather than peel the
connector off the board.

If you glue it first (with a decent material, NOT a brittle "superglue" type)
and THEN repair the solder work, you'll have a much greater chance of a long
term result.

What would you recommend instead? I use 24 hour epoxy.

Some glues applied after soldering will actually pre-stress the
solder bonds and predispose the assembly to further failure.

Huh? Most glues shrink, not expand when drying. What type of glue
are you thinking of? The Duco and plastic model cement glues won't
stick to the plastic. The Urethanes work as good as epoxy, but is not
very good at gap filling or for non-parallel surfaces.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[franco]

On Jun 14, 11:45 pm, Eeyore <rabbitsfriendsandrelati...@hotmail.com>
wrote:

franco wrote:
I have a Korean made Sherwood receiver circa 1980 that distorts on the
right channel only:
with all inputs (eliminating the sources);
with any set of speakers (not the speakers);
at all volumes (eliminating things before the volume knob);
with the headphones (eliminating the power stage?).

No, the headphones will normally be run from the 'power stage'.
not the preamp stage?

Does anyone have any advice troubleshooting this? I'm comfortable
replacing electronic components in circuit boards (when I say me I
mean my electronic savvy friend who is helping me out, He just
replaced leaky looking 1000u cap, but it didn't solve the problem) but
have no experience with stereo troubleshooting and would like to
attempt to fix this myself.

It's not difficult in principle. Do you have experience troubleshooting
other electronics aside from audio ?
some guitar tube amplifier stuff (very simple compared to this); my

friend helping me has experience in TVs and microwave ovens.

Posted to sci.electronics repair in addition.
Thank you.

Graham

 

[naza]

I have got a Matsui TV (link:
http://www.currys.co.uk/martprd/store/cur_page.jsp?BV_SessionID=@@@@0622967266.1213531520@@@@&BV_EngineID=ccfhadeegggiimicflgceggdhhmdgmk.0&page=Product&fm=null&sm=null&tm=null&sku=978626&category_oid=)
which I picked up from currys a while back. It has this strange noise
though. When the screen shows White or bright colours it gives out a
high pitched noise, but is silent for black. Is this a fault?

 

[Adrian C]

ll wrote:

Hi,
I am trying to locate the soft vinyl covers for the blade-style,
female ("Lucar") connectors.

Best off mentioning that you are in or near Oklahoma City ;-)

--
Adrian C

 

[Jeff Liebermann]

On Sun, 15 Jun 2008 19:21:40 -0700 (PDT), astroncer@yahoo.com wrote:

It still has solid solder, do I need to remove that, if yes any way of
faking it.

No. AFTER gluing the connector, and waiting for the epoxy to harden,
hit all the solder pads with some clean rosin core solder until it
reflows and is shiny. If inexperienced, practice with some eWaste.

As far as gluing, I got my question answered of doing it before
soldering, as the connection might break and it's pretty loose to
begin with.

Yep.

The practice with a decent
soldering iron and some junk electronics. When you figure out which
end of the iron to grab, you're ready to attack the laptop.

I think I got past the wrong end part, more than a few times,

I haven't. I was holding the soldering iron in my mouth and managed
to burn a big hole in my jacket.

I might have some boards of this and that under the house crawlspace.

Check the local eWaste depository.

Incidentally, I'm impressed that you're able to take it apart. That's
generally not an easy thing to do.

Thanks, I kinda looked at how it was put together, then thought how to
do it in reverse. I just took my time, do a post or two on the usenet,
get back to it. I took pictures through the process though.

Hint: The hard part is remembering where the screws go. That's why I
take photographs with a digital camera. As soon as I get the covers
off, I print the photos on my laser printer. I then circle the screws
as I remove them. On Compaq hardware, which tends to use many
different sizes and lengths, I place a 2nd copy of the print on a
piece of styrofoam. I then shove the screws through the print, and
into the styrofoam. No more guessing which screw goes where.

I have looked for a motherboard for it, but no luck. I still might try
this.

If it's only the connector, you're on the right track. No need to
replace the board. However, if you have the time, I would replace the
connector instead of gluing it. I only glue connectors on worthless
laptops, or where the customer is in a big rush and can't wait a few
days for the connector to arrive.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Ayushi Mehra]

Sony 610E Camera camcorder comes with a CCD sensor, has 40x optical
zoom and 2000x digital zoom. It has a 2.7-inch LCD color display,
white balance and recording mode is HQ, SP and LP. The camcorder
supports 3 inch DVD-R, DVD+RW, DVD-RW, DVD+R DL discs for shooting
videos and Memory Stick Duo for stills. Other features include
Widescreen Video, Image Stabilizer, Built-in speaker, Super Night Shot
Plus and Touch-screen control. The videos can be recorded in MPEG2
video format with a recording speed of HQ, SP and LP.
To buy this Sony 610E Camera
Please visit:
http://www.naaptol.com/buy-online/WO-best-deals-shopping-W10696O/cameras/camcorders/sony_610e.html

 

[zalek]

On Jun 19, 10:57 pm, Paul <nos...@needed.com> wrote:

zalek wrote:
Hello, I am trying to build a new PC. After connecting all the parts,
I turned the switch on and... nothing.
I suspect that the power supply is not working, or the circuit on the
motherboard that switches the power supply on is not working.
When I flip the switch on the back of the power supply on, the
keyboard LED turns on for a second. However, when I press the major
switch, nothing happens. No fans move, and there are no noises. I
checked the major switch with an ohmmeter, and the switch seems like
it works.
I'm not sure if the power supply or the motherboard circuit that
starts the power supply isn't working.
So my question is, how can I check if the power supply is working?
Thank you very much

Zalek

There is a power supply spec here, so you can see the signal names.

http://www.formfactors.org/developer/specs/ATX12V_PSDG_2_2_public_br2...

To start with, the power supply is split into two pieces. The +5VSB
output, is available as soon as the rear switch is turned on. The +5VSB,
in turn, flows down the main power cable and powers some motherboard
logic.

The second half of the power supply, operates the 3.3V/5V/12V/-12V
outputs. The power is "soft switched" by means of the logic level
on the PS_ON# signal. The PS_ON# signal normally is pulled to +5V,
by an internal resistor. To start the supply, PS_ON# needs to be
grounded (zero volt level).

Inside the computer, the chain of command looks like this.

Front Motherboard Grounds Main To main ATX
Power ------------ Logic runs ----- PS_ON# --------------- part of supply,
Switch on +5VSB to operate Cable fans start to spin
(momentary (latches when PS_ON# is
contact) signal) grounded

An ATX supply can be operated on the test bench.

1) Connect a dummy load to the supply. You could use a couple old
hard drives, and connect them to the Molex connectors. I have
a home made load box that I use.

2) Switch on power supply at the back.

3) Connect Green to Black with a paper clip. The fans should spin.

Then, you can use a multimeter to measure the voltages if you want.
I use a load box, drawing a light load (<100W), to help ensure
that the power supply will be regulating properly when I measure
it. I actually test new power supplies, before I use them.

Paul

Paul,
Thanks very much for answering. I understood your explanation - now I
know why the LED on the keyboard was turned on when I turned the back
switch on.

I'm not sure what you meant by "Connect Green to Black". I looked at
all the cables coming from the power supply, and I didn't see anything
green. Only yellow, red, white, black, blue, and purple.
Thanks again, I really appreciate the help.
-Zalek

 

[Nicholas Sherlock]

zalek wrote:

Hello, I am trying to build a new PC. After connecting all the parts,
I turned the switch on and... nothing.
I suspect that the power supply is not working, or the circuit on the
motherboard that switches the power supply on is not working.
When I flip the switch on the back of the power supply on, the
keyboard LED turns on for a second. However, when I press the major
switch, nothing happens. No fans move, and there are no noises. I
checked the major switch with an ohmmeter, and the switch seems like
it works.
I'm not sure if the power supply or the motherboard circuit that
starts the power supply isn't working.
So my question is, how can I check if the power supply is working?
Thank you very much

Something really simple to check - Is the power button cable connected
correctly to the motherboard?

Cheers,
Nicholas Sherlock
-----------------
www.Newsgroup-Binaries.com - *Completion*Retention*Speed*
Access your favorite newsgroups from home or on the road
-----------------

 

[ancient-time-traveler]

On Jun 20, 3:42 am, "William Sommerwerck" <grizzledgee...@comcast.net>
wrote:

Sorry about this posting. I was intended for another group. I goofed.

MY phone is in my post for all to see.............................

I call the author He said that he was making a JOKE. I already knew it
was a joke. Although not obvious to a non-technical 11,000 is a
ruinous smart aleck statement. He was trying to be smart-ass making
me the butt of his mean-spirited joke. He was non apologetic and
defend his attempt at humor. I did not post so that I could be made
fun at. Hateful is mild to what I feel toward him. I loath such
unwarranted trashing of my post. I object most vigorously He came
across as arrogant and with a huge superiority complex needing to
inject himself in such a way not to help but to show off how smart he
is. I ask him not to post on my postings in the future . I was trying
to sell a very coveted part that some collector would need and
appreciate, Not to become a point of ridicule. That was his intent. I
do NOT like people disrespecting me and laughing at me. He was very
condescending on the phone. I believe a person who is really very
smart does not try to do it at someones else's expense. I hope that
this is not what this forum is all about. I told him he should try out
his comedy out on a JOKE forum but leave me out of it, leave me alone.
I will not tolerate it. Thank you Irvin Sr.

 

[ancient-time-traveler]

On Jun 20, 3:42 am, "William Sommerwerck" <grizzledgee...@comcast.net>
wrote:

Sorry about this posting. I was intended for another group. I goofed.

MY phone is in my post for all to see.............................

I call the author He said that he was making a JOKE. I already knew it
was a joke. Although not obvious to a non-technical 11,000 is a
ruinous smart aleck statement. He was trying to be smart-ass making
me the butt of his mean-spirited joke. He was non apologetic and
defend his attempt at humor. I did not post so that I could be made
fun at. Hateful is mild to what I feel toward him. I loath such
unwarranted trashing of my post. I object most vigorously He came
across as arrogant and with a huge superiority complex needing to
inject himself in such a way not to help but to show off how smart he
is. I ask him not to post on my postings in the future . I was trying
to sell a very coveted part that some collector would need and
appreciate, Not to become a point of ridicule. That was his intent. I
do NOT like people disrespecting me and laughing at me. He was very
condescending on the phone. I believe a person who is really very
smart does not try to do it at someones else's expense. I hope that
this is not what this forum is all about. I told him he should try out
his comedy out on a JOKE forum but leave me out of it, leave me alone.
I will not tolerate it. Thank you Irvin Sr.

 

[bob urz]

Brad wrote:

Hi,

I have two WinBook XL2 laptops with Windows 98se. Most of the time, I use
them off line (off the Web) and I don't need the CPU running at full speed
(400Mhz). The problem is the noisy fan that cools the CPU. This fan is not
defective since it is noisy on both laptops and it runs constantly after a
warm up period.

I could not find anything in "Setup" or the manual that allows you to
reduce the CPU speed.

Is there a utility that would allow me to slow down the CPU, thus
reducing the heat up so the fan doesn't constantly run?

Thanks in advance, Brad

Before you type your password, credit card number, etc.,
be sure there is no active keystroke logger (spyware) in your PC.

You already have the ultimate CPU slowdown, a 400MHZ CPU.

Newer intel CPU's have speedstep that will automatically throttle down.
Yours is probably too to have it. Laptops run hot. get a cooler plate
for the bottom if you have to.

bob


----== Posted via Pronews.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.pronews.com The #1 Newsgroup Service in the World! >100,000 Newsgroups
---= - Total Privacy via Encryption =---

 

[1PW]

JANA wrote:

I would guess that in your situation what happened is to be expected. If
you were working in an actual lab with calibrated instruments and had to
be working with people in other countries, metric would be the standard.
In fact, if you were to buy any modern laboratory type instruments for
research, many of them come in metric only.

O'scopes, yes. Liquid and gas pressures and flow, no. Ultra high
vacuum, Torr. Distances and thicknesses, hardly. Engineering
drawings produced locally, inches & feet.

(If I had produced an engineering CAD drawing, whose dimensions were
only metric, the drawing would have been returned, ignored or lost.)

Nuts, bolts, screws and washers, nope.

I was reading some articles that explained that the reason why the US
did not go with metric was because of the massive cost. At the time when
many of the countries around the world changed most of the instruments
for commercial and consumer use were mainly mechanical and the
electronic ones were not easily re-programmable. The cost of changing
would have been very high.

Maybe cost /was/ the general excuse we hid behind. More likely it
was our human reluctance to change, coupled with insufficient resolve
added to our imperialistic attitudes.

In Canada the change was done, but at a very high cost. Canada was
forced to change because of the situation in how they do business with
Europe and Asia. There are very few countries left in the world that are
not on the metric system. We'll see what happens over the next 10 years
or so if the US will be forced to change over to metric.


We might have looked into having Canadian folks come down for more

than a few years and be our overseers. ;-) If we take a look down the
aisles of today's hardware stores, metric is not easy to find. Our
liquids are still selling by the pint/quart/gallon. Other commodities
are sold by ounces/pounds/feet/inches. If today's children aren't
taught to talk/think/breath metric, we will *never* make the change.

I suppose might still makes right...

--
1PW Just another ugly American.

@?6A62?FEH9E=6o2@=]4@> [r4o7t]

 

[Sam Goldwasser]

"DaveM" <masondg4499@comcast99.net> writes:

"Sam Goldwasser" <sam@plus.seas.upenn.edu> wrote in message
news:6w63s1at4v.fsf@plus.seas.upenn.edu...
I know, not really repair, but this newsgroup has at least as good
suggestions as the others and I'll cross-post to sci.electronics.misc.

I need to either build or acquire an up/down counter with LED display
that is at least 5 digits, 7 preferred. Count speed is 10 MHz max.

I found the Maxim ICM7217
(http://datasheets.maxim-ic.com/en/ds/ICM7217-ICM7217C.pdf)

which seems easy enough to use - 2 of these and a bunch of 7 segment LED
displays. But I'm open to other suggestions.

Even if someone had a complete unit scrapped out they'd be willing to
sell cheap!

Thanks.

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


Sam,
I thought that Velleman made a kit that would do your bidding, but it seems that
their up/down counter kit is for low speed (switch) inputs... only 200 counts
per second. Red Lion Controls makes a 10KHz presettable counter; I see those
infrequently on Ebay, usually in the $40 - $80 range.
I remember servicing some HP presettable counters a number of years ago, and I
know that one of those would easily work for you, but a quick search on Ebay
turned up nothing. Neither Ramseykits nor any of the other kit makers have
anything useful.
So it seems, at first glance, that your ICM7217 solution might be the most
expedient.

Yeah, even the ICM7217 may be marginal. I see it's only guaranteed to
2 MHz, though 5 MHz typical. It's not that there is a need for a
sustained count rate above that, but I can't guarantee that two
clocks won't occur quite close together.

Thanks for thinking about it.

--- 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.

 

[Tim]

In article <j5l4641gc5kn70rghga8viua91ko01omsb@4ax.com>,
letterman@invalid.com says...

Just how dead are doornails?
Come to think of it.......
What the hell is a doornail anyhow?

Try Searching the net....

Too Lazy?

Try here;

http://www.thefreedictionary.com/doornail



- Tim -

 

[ll]

On Jun 15, 11:17 am, "Ron(UK)" <r...@lunevalleyaudio.com> wrote:

Adrian C wrote:
ll wrote:
Hi,
I am trying to locate the soft vinyl covers for the blade-style,
female ("Lucar") connectors.

Best off mentioning that you are in or near Oklahoma City ;-)

If you can`t find any, you could make some using clear heatshrink and
some kind of former.

Ron

Thanks - great idea..I'll give it a try

 

[whit3rd]

On Jun 24, 12:07 pm, msg <msg@_cybertheque.org_> wrote:

I would appreciate a discussion on what environmental factors
cause  white plastic equipment cases... to yellow

There are two or three causes. Firstly, UV light can
cause 'color centers' to form, kind of like the purple tint
that develops in desert glass. Secondly, polymers
are developed from unstable (monomer) ingredients,
and there are complex aging characteristics, which
cause the plastics to shrink, embrittle, or change color.

Dirt, also, may bond to the surface; if normal household
cleaners (soap, Windex, Formula 409 etc.) don't work,
it might be useful to apply a mild abrasive (toothpaste
or metal polish).

Unusual cleaners including waterless hand cleaner,
denatured alcohol (for fingerprints on keyboards), dilute
lye (for smokestains), vinegar (for some mineral dusts)
have proven effective. Isopropyl alcohol is NOT
recommended for translucent or transparent plastics.

 

Is the joint contact on http://www.geocities.com/anglomont/hvr-d.jpg
connected to anode of 2x062h(it should be a diode) ?