Toshiba TV29C90 problem; Image fades to black...

[Mr. Lee]

John i removed the hoz output transistor and plug in the set and tv was
pulling over 4 amps so i use a 300 Watt lamp in circuit and the B+ was 265V
on the 130v line tv was pulling over 3 amps with lamp in circuit! Any
ideas??

Ok ! Then trouble shoot the SMPS...with the HOT out of circuit.

kip

--
"Watch the return E-Mail addy its false"
"Mr. Lee" <bubba@biff.com> wrote in message
news:J984b.54185$0u4.11761@news1.central.cox.net...
don't know because when i plug in the tv the high voltage goes up and
pop
the transistor shorts out!


What is the standby voltage on the HOT ??
kip

Set came in shop with shorted Horz output transistor. Replace part
and
power
up tv and high voltage came up and pop horz output thansistor
shorted!
Any
ideas??

Thanks
Check driver transfomer horz output transformer and caps.

No luck.

 

[Harry Bloomfield]

In article <nadpkvg897tjma9ea2890f277spvvaiodc@4ax.com>,
noname@zoominternet.net says...
| Completely dead when operating from battery or ac adapter, except with
| the adapter the green light is lit, but no other signs of life at all
| even after hitting the power button. Any ideas?? I understand that
| these units have a common problem with the adapter jack going bad. But
| how do you disassemble these things? What's the trick?
|
|

If it is lighting the power LED, it suggests the power is getting
through the power jack?

I have a Presario, but not the same model as yours. My power jack broke
up internally a few weeks after purchase. I decided to repair it
myself..

To get to the motherboard you just simply remove the philips screws
under the base. Start with those under the mouse pad and this comes off
first. then those under the keyboard. Once these are out of the way,
you should be able to remove the hard drive, heat sink and other items,
then finally the motherboard.

I found it made for a more robust job, to replace the power jack with
one intended for panel or hole mounting, fixed with a threaded ring.
The hole in the case will require to be drilled out a little larger to
accept one of these, then a couple of short bits of wire link it to the
motherboard. There was just enough room to fit this, so it can be a
little tricky.

It might be a good idea to take some digital photographs, as you strip
it down, to remind you where things belong, when rebuilding it. Compaq
used to have some laptop repair manuals freely available on-line.




--
Regards,
Harry (M1BYT)...

Remove the 'NOSPAM' in my email address to reply.

Free Amateur Radio Courses:-
http://www.ukradioamateur.org

 

[Anonymous]

The cover will help to protect the CD (CDROMs, CD-Rs CD-RWs, etc) against environmental damages such as sunlight, light, dust and maybe humidity. It seems to me that these are the major causes to lost of data in some cases.

At where I am, Fujifilms CD is the only one that is made in Japan. Other brands even such Sony, Maxell, TDK and Verbatim are made in various countries. Maybe I should stick with Fujifilms.

You wrote

But, unlike VHS cassette, CD discs did not require additional measures of
protection as long as you handled your discs properly.

-=-
NOTE: This message was posted via one or more anonymous remailing services.

 

[Nomen Nescio]

The cover will help to protect the CD (CDROMs, CD-Rs CD-RWs, etc) against environmental damages such as sunlight, light, dust and maybe humidity. It seems to me that these are the major causes to lost of data in some cases.

At where I am, Fujifilms CD is the only one that is made in Japan. Other brands even such Sony, Maxell, TDK and Verbatim are made in various countries. Maybe I should stick with Fujifilms.

You wrote

But, unlike VHS cassette, CD discs did not require additional measures of
protection as long as you handled your discs properly.

 

[Jim Yanik]

Fred Abse <excretatauris@cerebrumconfus.it> wrote in
newsan.2003.08.28.18.56.59.982843.660@cerebrumconfus.it:

On Thu, 28 Aug 2003 02:17:41 +0100, Jim Yanik wrote:

Bad news here;TEK did not make service manuals with real schematics and
component parts lists for the TDS series scopes,and the PS were
purchased units.The TDS scopes are intended to be module-exchange
service only

Tek have gone right down the pan.

I suspect MBAs at work :-(

Absolutely correct.

TEK sold off their ICO/hybrid manufacturing unit;had to drop an entire
product line as a direct result.
TEK laid off or reassigned much of their Service Support staff.
Manuals without the TEK schematics,parts lists,and the invaluable Circuit
Description section are MUCH cheaper to make.
And they don't have to distribute service data to service centers
anymore,as they closed those.Only the DC field office is left.

Beancounters :-(
--
Jim Yanik,NRA member
jyanik@kua.net

 

[mike]

Arthur Jernberg wrote:

Go to their respective web site and download any application software and
upgrades that apply. Using the appropiate connect cable write the
information to the internal EPROM, make absolutely sure you follow any and
all instructions posted at the web site. Failing that it may be justified to
send the item to them for service. I know Garmin does have a very nice site
with technicial advice.
"mike" <spamme0@juno.com> wrote in message news:3F4FEBE5.7010005@juno.com...

Been there Done That. No upgrades or sw for the 310, others yes, 310
no. Here come da hacksaw...
mike

Andre wrote:

mike <spamme0@juno.com> wrote in message

news:<3F4E888A.8080400@juno.com>...

I have a Magellan GPS310 that sits there acquiring and losing
satellites without ever getting a position fix.
Is there a secret key combination to reset the thing?



Sounds like the RF front end may be damaged, or a loose aerial plug
inside.



Failing that, how does one get it open? I'd hate to take
a hacksaw to it and find out I only had to "push here".


Usually "hidden" catches. It may be ultrasonically welded if it is a
waterproof model..



mike

Thanks for the input, but I stll need answers to the questions I asked.
How do I reset it? worth a try...
What is the exact procedure to open the case? eg, how to release the
"hidden catches".
Surely I'm not the only one ever to want to disassemble a Magellan...
Thanks,
mike

--
Bunch of stuff For Sale and Wanted at the link below.
laptops and parts
4in/400Wout ham linear amp.
Honda CB-125S
400cc Dirt Bike 2003 miles $450
Police Scanner, Color LCD overhead projector
Tek 2465 $800, ham radio, 30pS pulser
Tektronix Concept Books, spot welding head...
http://www.geocities.com/SiliconValley/Monitor/4710/

--
Bunch of stuff For Sale and Wanted at the link below.
laptops and parts
4in/400Wout ham linear amp.
Honda CB-125S
400cc Dirt Bike 2003 miles $450
Police Scanner, Color LCD overhead projector
Tek 2465 $800, ham radio, 30pS pulser
Tektronix Concept Books, spot welding head...
http://www.geocities.com/SiliconValley/Monitor/4710/

 

[Nigel]

download a pdf copy of the user manual at http://support.panasonic.co.nz/


"Just Allan" <justallan@COLDhotmail.com> wrote in message
news:d883lv45e0583c04orc5gpsvlcga50k5lu@4ax.com...
Has anyone got a user manual, or know how to tune a Panasonic NVJ1
vcr? (It's similar to other models with "NVJ" in the model.) I have
a service manual here, but the tuning instructions aren't in it!?

Allan.

 

[john]

Yes you have to trouble shoot the power supply
as 265Volts is WAY to high loook for bad caps
or resistors in Power supply.
What is the IC in the poweer section a STKxx or STRxx ?

kip


--
"Watch the return E-Mail addy its false"
"Mr. Lee" <bubba@biff.com> wrote in message
news:y194b.54363$0u4.3085@news1.central.cox.net...

John i removed the hoz output transistor and plug in the set and tv was
pulling over 4 amps so i use a 300 Watt lamp in circuit and the B+ was
265V
on the 130v line tv was pulling over 3 amps with lamp in circuit! Any
ideas??

Ok ! Then trouble shoot the SMPS...with the HOT out of circuit.

kip

--
"Watch the return E-Mail addy its false"
"Mr. Lee" <bubba@biff.com> wrote in message
news:J984b.54185$0u4.11761@news1.central.cox.net...
don't know because when i plug in the tv the high voltage goes up and
pop
the transistor shorts out!


What is the standby voltage on the HOT ??
kip

Set came in shop with shorted Horz output transistor. Replace part
and
power
up tv and high voltage came up and pop horz output thansistor
shorted!
Any
ideas??

Thanks
Check driver transfomer horz output transformer and caps.

No luck.

 

[PaulH96636]

There are no longer any batteries on the market with a
native voltage stable enough to use as a reference.

Yep, istr that there was one type of mercury battery which could indeed be
used as a reference cell, but nowadays
they cannot be made because of disposal problems. Perhaps they could be made
under the stipulation that they be made available only to technicians or supply
houses, so that the general population would not have ready access, and thereby
not contribute much to pollution
(ok, so that's a pipe dream... ;-) ) -ph

 

[LASERandDVDfan]

At where I am, Fujifilms CD is the only one that is made in Japan. Other
brands even such Sony, Maxell, TDK and Verbatim are made in various
countries. Maybe I should stick with Fujifilms.

Not all Maxell CD-Rs are made in Taiwan. If you look at Maxell's Pro line of
CD-R discs, they are also made in Japan. The Maxell Pro discs are made by
Taiyo Yuden.

As for staying away from Sony, I can see that. While I've found their drives
to be very good workhorses, their media seems to be getting progressively
worse.

Staying away from Maxell is a maybe. Some of their discs have been made by
third parties, but most discs are usually made by Maxell/Hitachi themselves
according to the ATIP. Their discs actually test out pretty good, although not
quite as well as Fuji, IMO.

TDK is a REAL iffy. Before, they made their own discs. Now, their discs seem
to be made by Ritek, which is not that great IMO.

Verbatim is what I consider the tops over a lot of discs that are made in
Taiwan. Even though they are made in Taiwan, their manufacturing is still
reasonably good and their AZO dye formulation is very good. Many are OEMed by
CMC Magnetics under the supervision of Mitsubishi Chemicals.

As for Fuji, that's pretty much all I use now, as well. Although, allow
flexibility in your choice. If you come across a pack of Taiyo Yuden discs,
grab them as they will be the same quality as the Fujifilms. Afterall, Fuji
discs are currently made by Taiyo Yuden! - Reinhart

 

[Mr. Lee]

No reg ic only a switching transistor om the primary side of the
transformer.
"john" <va3mmTAKEOUTTHIS@niagara.com> wrote in message
news:newscache$43ihkh$xs3$1@newsfeed.niagara.com...

Yes you have to trouble shoot the power supply
as 265Volts is WAY to high loook for bad caps
or resistors in Power supply.
What is the IC in the poweer section a STKxx or STRxx ?

kip


--
"Watch the return E-Mail addy its false"
"Mr. Lee" <bubba@biff.com> wrote in message
news:y194b.54363$0u4.3085@news1.central.cox.net...
John i removed the hoz output transistor and plug in the set and tv was
pulling over 4 amps so i use a 300 Watt lamp in circuit and the B+ was
265V
on the 130v line tv was pulling over 3 amps with lamp in circuit! Any
ideas??

Ok ! Then trouble shoot the SMPS...with the HOT out of circuit.

kip

--
"Watch the return E-Mail addy its false"
"Mr. Lee" <bubba@biff.com> wrote in message
news:J984b.54185$0u4.11761@news1.central.cox.net...
don't know because when i plug in the tv the high voltage goes up
and
pop
the transistor shorts out!


What is the standby voltage on the HOT ??
kip

Set came in shop with shorted Horz output transistor. Replace
part
and
power
up tv and high voltage came up and pop horz output thansistor
shorted!
Any
ideas??

Thanks
Check driver transfomer horz output transformer and caps.

No luck.

 

[Jim Yanik]

paulh96636@aol.comkojunk (PaulH96636) wrote in
news:20030831121400.18495.00000308@mb-m13.aol.com:

There are no longer any batteries on the market with a
native voltage stable enough to use as a reference.

Yep, istr that there was one type of mercury battery which could
indeed be used as a reference cell, but nowadays
they cannot be made because of disposal problems. Perhaps they could
be made under the stipulation that they be made available only to
technicians or supply houses, so that the general population would not
have ready access, and thereby not contribute much to pollution
(ok, so that's a pipe dream... ;-) ) -ph

What for,when you can use an ordinary alkaline cell or 2 and a bandgap
reference diode or IC,and get better accuracy,and better tempco and
portability?
If you wanted to get elaborate,you could stack several references and have
a range of voltages to choose from.

--
Jim Yanik,NRA member
jyanik@kua.net

 

[Nigel]

What were they in ?

Make, model, type of equipment,etc.


"MacMan85" <macman85@mewgull.nildram.co.uk> wrote in message
news:dpo5lv04t2qcmedu60ff6evle9gd3h7u97@4ax.com...
Hi,

I have a couple of dead transistors which I can't find any reference
for or specifications. Both are TO-126 cases and are used as drivers
for high-power MosFETs. The type numbers are:

123T (mfg code H)

121 (mfg code ON) - this one could be type 143 (seen in another piece
of similar equipment)

Exhaustive searches in all the usual internet sites reveal nothing!
Can anyone shed any light on these?

Thanks,
Richard

 

[Arthur Jernberg]

Sounds like maybe you need to get the proper schematic for this particular
set, Eh. Not to be a pain but SONY tends to be quite particular with changes
from one particular set to another regarding component location and
applications. You may actually find that you are looking for an item that is
not even applicable to your particular set and that it may require a
parameter adjustment. Just food for thought.
"Bill" <elect21st@aol.com> wrote in message
news:8fb59540.0308311512.1606582e@posting.google.com...

I have a Sony KV32XBR10 with sound problems. I'm trying to bypass
SBX1593 which is NLA, but NOBODY seems to know where it is exactly on
this chassis !! Is it similar to SBX1637 which I replaced many times ?
Every time I go back to this set and look around with lights and
magnifier but still can't find it ! I would like to hear from someone
who actually did the bypass and knows for sure. Thanks !

 

[WbSearch]

Arthur is correct. I have a Sony VCR that my repair manual states there is a
battery, but shows a capacitor to keep the memory alive during loss of power.
In actuality, my unit has a jumper wire in the location, and no memory backup.
I placed calls to the Sony technicians, they insist there is a battery, parts
sales personnel insist there is a capacitor.

 

[sPoNiX]

On 1 Sep 2003 08:28:41 -0700, bigcat@meeow.co.uk (N. Thornton) wrote:

The only data I dont have is the failure modes for TVs 5 and 6. To
this day no-one knows why those 6 TVs died. What could have happened
in this tale of the Bermuda TVriangle?

What were the failures of sets 1-4? When you say the sets "died" are
they actually dead as in no picture or sound?

sPoNiX

 

[MacMan85]

Located in a Nikkai model QM82 800W 12V DC - 240V AC power inverter.

The transistors are used to switch the quasi-sine output into a MosFET
bridge (4 x IRFP450 FETs, rated at 500V, 14A) - the bridge is
switching about 380V DC but I think the drivers are running at 12V or
thereabouts since the FET gates are rated at 20V max.

Richard

On Mon, 1 Sep 2003 22:32:25 +1200, "Nigel" <Nigel@nospam.com> wrote:

What were they in ?

Make, model, type of equipment,etc.


"MacMan85" <macman85@mewgull.nildram.co.uk> wrote in message
news:dpo5lv04t2qcmedu60ff6evle9gd3h7u97@4ax.com...
Hi,

I have a couple of dead transistors which I can't find any reference
for or specifications. Both are TO-126 cases and are used as drivers
for high-power MosFETs. The type numbers are:

123T (mfg code H)

121 (mfg code ON) - this one could be type 143 (seen in another piece
of similar equipment)

Exhaustive searches in all the usual internet sites reveal nothing!
Can anyone shed any light on these?

Thanks,
Richard

 

[Sir Charles W. Shults III]

To add to this, we have NO failure data on any of the sets. Can't be much
help that way.

Cheers!

Chip Shults
My robotics, space and CGI web page - http://home.cfl.rr.com/aichip

 

[klmok]

On 1 Sep 2003 08:28:41 -0700, bigcat@meeow.co.uk (N. Thornton) wrote:

Hi. A true life conundrum for you.



Same examination, and again no cause found. Dealer C decides at this
point to refund the money, and advises customer to rent instead, from
their main competitor.


Try adding a surge protector on the power cord and add a stick-on seal

to that connection to prevent tampering. At least the dealer can
determine if power spikes is a cause. What about the polarity of the
power plugs?

 

[Jeff Liebermann]

On 1 Sep 2003 08:28:41 -0700, bigcat@meeow.co.uk (N. Thornton) wrote:

A customer gets 4 used TVs from dealer B, one after the other. Every
one of them dies within a week, thats the reason for the replacements.
Customer A is pretty unhappy with dealer B, blaming their duff
products.

I should point out that this story smells like a hoax because of the
lack of make, model, and numerical details. However, I'll treat it
seriously (for no obvious reason). I also don't know of any dealer
that would replace 4ea TV's under warranty. One is the norm, two for
good customers, but not three replacements.

It would have been helpful if you supplied some details such as the TV
makes and models, as well as the results of any post mortem analysis.
Some clues as to the exact desciption of "dead" would be helpful.

I'll assume that the sets are dead as in no power supply or no
picture. A short list of possibles are:

1. Major power glitches via the AC power.
2. Faulty ground on AC power.
3. Static electricity fries circuitry when touched.
4. Ionizing (nuclear) radiation breaks down circuitry. Is the owner a
nuclear power station employee that takes his work home?
5. EMP (Electro Magnetic Pulse). Proximity to large pulsed RF power
such as high power RADAR.
6. EMF (Electro Magentic Field). Proximity to a large magnetic or
electric field such as the transformer on an X-ray machine.
7. High voltage. Is there an operational Tesla coil in the house?
8. High power microwaves. Is someone experimenting with a microwave
oven with the interlock disabled and pointed at the TV set?

--
Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
(831)421-6491 pgr (831)336-2558 home
http://www.LearnByDestroying.com AE6KS
jeffl@comix.santa-cruz.ca.us jeffl@cruzio.com