Toshiba TV29C90 problem; Image fades to black...

I have a 29 that's excellent, however I need new fuses for it, both current
measuring fuses are blown, where's a good place to order new ones?
"Bob M." <xxxxx@yyyy.zzz> wrote in message
news:jE6dnSWi8Y6I1LWiU-KYvA@comcast.com...
The 187 and 189 meters are their top-of-the-line and are probably
replacing
many of the 80 series. The 189 can log about 1000 readings internally -
that's the only difference between the two. They retail for almost $400
but
sometimes you will find them on eBay for half that. I jumped on the
auction
at that price for a 189, then sold my 18-month-old 187 to a friend for the
same amount.

However, there are also things to be said for a good old 260. Hopefully he
will end up with both !

Bob M.
======
"Alan Harriman" <vtech@usol.com> wrote in message
news:miceiv04oj635va2pekebkqf1bidphfq72@4ax.com...
On 28 Jul 2003 18:50:28 -0700, captainvideo462002@yahoo.com (Lenny)
wrote:

My son who works with me in my electronics service business is
presently enrolled in an Electronics Technology course at the local
College. I introduced him to test equipment by getting him a used 260
and a new cheapo hand held digital from Harbor Freight, just so that
he could "get his feet wet". He's a hard worker, and a good boy and
now I would like to do something special for him. He has asked for a
Fluke portable meter with a case for his birthday.


The Fluke 87 III is an excellent meter. Especially useful is its peak
hold
feature, a must for troubleshooting shutdown circuits. They retail for
about
$350, but can often be found on ebay for $200 or less. See


http://search.ebay.com/search/search.dll?MfcISAPICommand=GetResult&SortPrope
rty=MetaEndSort&ht=1&query=fluke+87+III

Alan Harriman
 
"Stellijer" <howapropos@hotmail.nospam.com> wrote in message news:<SPKWa.24762$f%2.23107@fe05.atl2.webusenet.com>...
A group I'm in just got a used full sized VHS camcorder.

It cosmetically looks great and seems to generally function (image in
viewfinder, tape moves as it should, seems to be working 100%) BUT when viewing
the tape it supposedly recorded on, there's nothing on the tape. Not static or
a black screen with an apparent tracking signal but NOTHING. It would appear as
if the tape was erased but nothing recorded. It was a used tape and indeed the
original signal had been wiped clean.
Bias oscillator switching transistor is shorted collector-emitter , so
the bias oscillator is on in all modes . (seen this in "Television" a
few times)
Disconnect the erase head , and see if it then records (do this on a
totally blank tape, and it should work OK) .

-A


If I may assume for a moment that the camera WAS, indeed, in working condition
when it was shipped, what is likely wrong with it? Has anyone encountered a
problem similar to this before? Also importantly, can it be fixed reasonably
easily or should the group try to get its money back?

Please advise.
 
Thanks for the suggestions. I'll check out the prices of silver loaded paint
and, if I use it, promise not to 'slather it all over'. The demister repair
paint looks good too. I have used it in the past with success but forgot about
it. And Loctite - they have so many different variaties I don't know why I
didn't think of them. I'll post my results here in about a week.

Thanks again all

Robert
 
wbsearch@aol.com (WbSearch) writes:

Have a Micronta M/N 22-191 multimeter that recently won't display zero only on
DC at the 2 volt selection or higher. The 200 mv scale is fine, as are all
scales of AC volts. The display shows between 0.100 - 0.500 volts, even when
the plus and minus leads are touched together. I have cleaned the PCB and
switches which helped for a short time. All diodes, resistors, batteries and
fuses check fine. All other functions work properly as well. Any other help
is appreciated.
Also, does anyone know what the 2 POT's are for? The manual doesn't go into
that detail. Thanks in advance.
In any case, a sudden change in behavior isn't an adjustment.

I also have a DMM that reads slightly off 0 on just 2 or 3 ranges but is
otherwise accurate.

--- sam | Sci.Electronics.Repair FAQ Home Page: 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 Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: The email address in this message header may no longer work. To
contact me, please use the Feedback Form at repairfaq.org. Thanks.
 
<< Orignal capacitors were 2200 uF @ 35V, perhaps I can change them
to 2700 or 3300 uF, shall it have any side effects other than more LF
passthrough I should be aware of before I solder and try them on.
(Electrolytics are just put in series between power end, fuse and the
speakers). Or is there a better kind of elecrolytic I shall use in here. And
last question, what are differences between different marked 2N3055s? >>

Jonie-

I'm a little rusty, but it looks like 2200 uF should be OK to below 20 Hz for
an 8 Ohm speaker. I calculated that it would have a reactance of about 7 Ohms
at 10 Hz. (I haven't done that in years!) Is it possible your smaller new
capacitor is mis-marked?

I see no reason you can't substitute larger capacitors to improve low end
response. Today's capacitors may be smaller in size than those from 20 years
ago, so a higher capacitance should fit in the same space. Just be careful of
the bias adjustment. The voltage at the point where the capacitor connects,
could exceed the rating of the capacitor if the bias was off.

The letter at the end of the 2N3055 part number may be different for different
manufacturers. I normally associate the "K" suffix with the metal case version
of the transistor. Perhaps your original transistors were marked with a
proprietary letter to designate gain, so they could be used in matched pairs.
Just replacing one transistor might result in distortion, even after
compensating for a difference in bias adjustment. It might be beneficial if
you could devise some kind of gain test, and select the closest pair out of all
you can get your hands on.

Fred
 
On Sat, 02 Aug 2003 15:32:38 GMT, Doug Taylor hath writ:
Well digital TV is here to stay.
So is a lot of things. I don't have to participate.

The public in general is going to have a fit when they are
told to junk all their equipment and buy NEW digital stuff.
There'll be no fit here. It's been a number of years since
there was much other than wretched dreck on TV.

I'll save my money. I'll dust off my library card, and get some
long-needed exercise walking down to the local library several
times each week.

Jonesy -- sometimes I have to be forced into dropping bad habits.
--
| Marvin L Jones | jonz | W3DHJ | OS/2
| Gunnison, Colorado | @ | Jonesy | linux __
| 7,703' -- 2,345m | config.com | DM68mn SK
 
Doug Taylor wrote:

Well digital TV is here to stay.
Question is.... What do we do with all those millions of
analog TV's, VCR's, Video Cameras and Analog video test
equipment.
Ship it to third-world countries so they can have a chance of building a society
like ours was 40 years ago at least.
Beats trashing it.
 
You were not answering the post to which you responded, but before trashing
a mb with suspect BIOS; find the BIOS shorting pins and clear it out. Works
sometimes....

jak

"Peter" <pmhughes@ozemail.com.au> wrote in message
news:rehWa.13$0a.799@nnrp1.ozemail.com.au...
I reckon you're right about the bios chip having failed. Did you try
removing the bios chip and carefully reseating it?
In future when this happens get a replacement bios chip from
www.badflash.com

Peter
"jakdedert" <jdedert@bellsouth.net> wrote in message
news:0jfWa.8632$f%2.2068@fe05.atl2.webusenet.com...
Disconnect *everything* except for CPU & video! . If it won't POST
with
just CPU, mb, video and ps; something must be wrong with one of them.
Substitute each until you get POST.

If it does POST, keep reconnecting things--starting with RAM--until it
doesn't...BINGO!

jak

"Gary Tait" <taitg@hurontel.on.ca> wrote in message
news:ticthvsr2i4oni1268nmung38sbre9rfvs@4ax.com...
On Wed, 23 Jul 2003 13:48:56 GMT, techno2nospam@videotron.ca (Doug
Taylor) wrote:


Well here goes a run down of a typical PC repair experience
for me....

A friend gives me his old PC Pentium 100 Mhz as it's not working.
As a challenge I decide to dig into to see whats wrong.

First, I set it up on the bench, remove the modem and sound card
and restart it with only video card to see if It will boot.. Blank
screen.
Then I sub out the video card and reboot... Blank screen.
Could be power supply, although seems to be getting power O.K.
to drives etc, check power plug motherboard with meter...O.K.
Sub out power supply anyways to be sure. ...blank screen.
Hummmmm whats next....
Sub out memory and re-seat.... no go.
Reseat CPU ..... nope............
Check out motherboard to make sure it is not shorted to bottom metal
plate.(happened once before on another system)
What's next.... motherboard or CPU....
Go out and buy used Pentium 125Mhz motherboard with CPU.
Sub CPU.... no go ....
Sub motherboard & CPU ....BINGO ... we got a winner......

Have to cut bigger hole in case for PS2 mouse & keyboard of new
motherboard as old motherboard had COM port mouse and DIN keyboard
plug.

Plan to put Linux on this system and use as a learning tool.

Question: Do you people have some constructive input into
the method I used to troubleshoot this system?

I'm kinda old(54) dyslexic & semi-retarded with bad eyesight,
but besides that I'm not a total idiot. 8*)

My conclusion is that the BIOS Rom failed.
What do you think?

Doug

Try disconnecting drives. Try a known working video card, or
that video card in a known working system. Same with other components.
 
I didn't mean to imply I was going to mess with the POT's. I did find in the
manual they are to calibrate the DC and AC volts. So I assume they are OK and
haven't/won't change them. I agree something else is happening.
 
Why do you think China would need your used analog equipment? Just look on
the back of your brand new digital equipment and see what's written there:
Made in China!

"Jeff Liebermann" <jeffl@comix.santa-cruz.ca.us> wrote in message
news:j9ppiv4u7ujj268758j744a8qjtsutq52l@4ax.com...
On Sat, 02 Aug 2003 14:48:33 -0400, A E <aeisenhut@videotron.ca
wrote:

Doug Taylor wrote:
Well digital TV is here to stay.
Question is.... What do we do with all those millions of
analog TV's, VCR's, Video Cameras and Analog video test
equipment.

Ship it to third-world countries so they can have a chance of building a
society
like ours was 40 years ago at least.
Beats trashing it.

Most 3rd world countries have substantial tariffs and taxes on the
import of test equipment making such donations difficult, especially
if they have a domestic electronics industry to protect. For example,
China has spent the last 2 years reducing their cut:


http://www.mac.doc.gov/China/Docs/industryfactsheets/scientificequipment.html
There are ways to do such donations, but they are complex.

Drivel/Rant: I recently demonstrated a VCD (not super-VCD) playback
on a common DVD/VCD/CD player (encoded from DV). I kept repeating the
"it's digital" mantra which automagically proclaimed to those watching
that this was in some way superior to analog. It was a little better
than horrible, but because the local analog CATV is full of RFI, the
digital cable is full of over-compression artifacts, and over the air
is full of ghosts (mountain area), they were unable to notice the poor
quality of the VCD. I don't think that anyone present had actually
ever seen a decent video picture. However, because it was "digital"
several viewers proclaimed the VCD to be superior in some
undescribable way.

It's also fun to take an analog VCR NTSC output and display it on an
HDTV screen (re-encoded to MPEG-2 on a computah) and proclaim that the
conversion to digital has somehow "improved" the picture. Duh.

I predict a small market servicing those neanderthals that consider
analog to be superior to (over-compressed) digital (as in the tube
audio fanatics). Perhaps one should save some of the analog test
equipment.


--
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
 
"WbSearch" <wbsearch@aol.com> wrote in message
news:20030802091245.06272.00001524@mb-m03.aol.com...
Have a Micronta M/N 22-191 multimeter that recently won't display zero
only on
DC at the 2 volt selection or higher. The 200 mv scale is fine, as are all
scales of AC volts. The display shows between 0.100 - 0.500 volts, even
when
the plus and minus leads are touched together. I have cleaned the PCB and
switches which helped for a short time. All diodes, resistors, batteries
and
fuses check fine. All other functions work porperly as well. Any other
help
is appreciated.
Also, does anyone know what the 2 POT's are for? The manual doesn't go
into
that detail. Thanks in advance.
If cleaning the PCB and switches solved the problem previously, there may be
something there that needs further investigation. Look vewy, vewy closely,
using a magnifying glass or other high-powered optics, at the CPB and the
area around the switches for anything that may look out of place. Like a
burned area such as may be caused by arcing. Have you used the DMM to check
a high voltage source just prior to it exhibiting the problem? How about
moisture or spilled liquid? Or component leads touching?
In this case, your eyes may be your best tool.

Cheers!!
--
Tweetldee
Tweetldee at att dot net (Just subsitute the appropriate characters in the
address)

Time is what keeps everything from happening all at once.
 
On 02 Aug 2003 13:12:45 GMT, wbsearch@aol.com (WbSearch) wrote:

Have a Micronta M/N 22-191 multimeter that recently won't display zero only on
DC at the 2 volt selection or higher. The 200 mv scale is fine, as are all
scales of AC volts. The display shows between 0.100 - 0.500 volts, even when
the plus and minus leads are touched together. I have cleaned the PCB and
switches which helped for a short time. All diodes, resistors, batteries and
fuses check fine. All other functions work porperly as well. Any other help
is appreciated.
Also, does anyone know what the 2 POT's are for? The manual doesn't go into
that detail. Thanks in advance.
You may have checked this already but..............if it has a
rotary switch built into a circuit board then check to make sure
that no conductive smears have formed between the different
contacts of the switch.
 
On Sat, 02 Aug 2003 15:32:38 GMT, techno2nospam@videotron.ca (Doug
Taylor) wrote:

Well digital TV is here to stay.
Question is.... What do we do with all those millions of
analog TV's, VCR's, Video Cameras and Analog video test
equipment.
The actual TVs and VCRs will still work, as there will (hopefully) be
digital STB convertors with analog outputs cpmatible with old analog
TVs.
 
On Sat, 02 Aug 2003 22:37:15 -0400, Gary Tait <taitg@hurontel.on.ca>
wrote:

On Sat, 02 Aug 2003 15:32:38 GMT, techno2nospam@videotron.ca (Doug
Taylor) wrote:


Well digital TV is here to stay.
Question is.... What do we do with all those millions of
analog TV's, VCR's, Video Cameras and Analog video test
equipment.

The actual TVs and VCRs will still work, as there will (hopefully) be
digital STB convertors with analog outputs cpmatible with old analog
TVs.
....and with a major (?) niche market for manufacturers.

Tom
 
Seeing as all TV programming is total crap these days, I prefer making my
own. It may not be much better, but I enjoy the process and I like doing
visual effects and illusions with the camera.

That's what I will do with my "obsolete" analog video equipment for many
more years to come.

The day digital TV is all that can be had is the day I stop watching TV
completely. I'm not paying good money for a signal that won't degrade as
gracefully or provide anywhere near as good a quality as a strong analog
signal...nor am I paying for a conversion box.

William
 
In article <dbfce1c0.0308010425.15c8a302@posting.google.com>,
davidlubich@hotmail.com (David Lubich) wrote:

Hello Group
My G3 Powerbook (bronze keyboard, 400MHz) no longer recognizes any
Firewire devices connected to it or even the CD-ROM drive. Even worse,
the trackpad has stopped working: thankfully, it still recognises USB
devices, so I can at least control it with a mouse.
These problems built up over a month - first the CD-ROM, then the
Firewire, then the trackpad - so I'm hoping that it's a software
problem.
Any help would be hugely appreciated.
Thanks
David
Try disconnecting any external devices you may have connected,
restarting, holding down the Command(Apple) Option and the P key and the
R key simultaneously (zapping the P RAM) through the start until the PB
chimes three times, then hold down the Command and Option Key until you
get asked if you want to rebuild the desktop file, if so unsaved
comments will be loste etc. Click OK and wait until a new inventory of
your hard drive is complete.

Your problems are weird enough that one of these simple proceedures
might solve them. You should rebuild the desktop every couple of weeks
or, if you handle lots of digital images, every few days.

Jim Scanlon
 
Lenny:
Did you verify that the B+ regulation is working properly and is holding the
proper voltage? .... Test with a variac on the AC line from about 105 to
125 Volts
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
-----------------------------------


"Lenny" <captainvideo462002@yahoo.com> wrote in message
news:d980bc2c.0308022206.5864f8c2@posting.google.com...
The complaint on this set was that sometimes it would work for a brief
time and then sometimes it would stay on for around 20 minutes. I
resoldered anything that looked suspicious and tried it. It will power
up and after about 10 seconds the picture will shrink in from all 4
sides and the set will quit. There is hardly enough time to decide
what to look at before this occurs. Does anyone have any information
on this set with this symptom? Thanks, Lenny Stein, Barlen
Electronics.
 
Michael:
Get into the menu or buttons on the television and switch from Stereo or SAP
.... to the MONO mode.... see if this changes the symptoms. Does this
happen on all channels? Some channels? Doe it happen with the A/V input?
I know it sounds like I am guessing here..... BUT you did NOT post the
MODEL NUMBER. I know that it is obvious to you that not all 15 year old
Toshiba televisions have the same features or the same circuitry. The more
information you post the better will be the replies. Always post the
model number.... always.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
---------------------------------------



"Michael" <nleahcimathotmaildotcom@nowhere.com> wrote in message
news:Xns93CBD25D41F51nleahcim@63.240.76.16...
Hi - I have a 27" Toshiba TV that is having some volume problems. It
fluctuates between playing kinda soft, to normal, constantly. Now that I'm
writing this - I think that it might be possible that perhaps just one
speaker is turning on/off. But I'm not sure just yet. So - where do you
think the problem is?
 
On Wed, 23 Jul 2003 13:48:56 GMT, techno2nospam@videotron.ca (Doug
Taylor) wrote:

A friend gives me his old PC Pentium 100 Mhz as it's not working.
As a challenge I decide to dig into to see whats wrong.
Just my two cents:
Is there a Dallas chip on the mobo? Black cube, dual inline,
print "Dallas" or "Odin" - sorry, don't remember the numbers.
AFAIR it is a clock with battery chip. I always wondered, who
ever got the brilliant idea to implement a battery into a chip
and then solder that to the board.
If there is, try to replace that. Estimated lifetime was about
ten years imho.
Eb
 
On Sat, 02 Aug 2003 14:48:33 -0400, A E <aeisenhut@videotron.ca>
wrote:

Doug Taylor wrote:
Well digital TV is here to stay.
Question is.... What do we do with all those millions of
analog TV's, VCR's, Video Cameras and Analog video test
equipment.

Ship it to third-world countries so they can have a chance of building a society
like ours was 40 years ago at least.
Beats trashing it.
Most 3rd world countries have substantial tariffs and taxes on the
import of test equipment making such donations difficult, especially
if they have a domestic electronics industry to protect. For example,
China has spent the last 2 years reducing their cut:

http://www.mac.doc.gov/China/Docs/industryfactsheets/scientificequipment.html
There are ways to do such donations, but they are complex.

Drivel/Rant: I recently demonstrated a VCD (not super-VCD) playback
on a common DVD/VCD/CD player (encoded from DV). I kept repeating the
"it's digital" mantra which automagically proclaimed to those watching
that this was in some way superior to analog. It was a little better
than horrible, but because the local analog CATV is full of RFI, the
digital cable is full of over-compression artifacts, and over the air
is full of ghosts (mountain area), they were unable to notice the poor
quality of the VCD. I don't think that anyone present had actually
ever seen a decent video picture. However, because it was "digital"
several viewers proclaimed the VCD to be superior in some
undescribable way.

It's also fun to take an analog VCR NTSC output and display it on an
HDTV screen (re-encoded to MPEG-2 on a computah) and proclaim that the
conversion to digital has somehow "improved" the picture. Duh.

I predict a small market servicing those neanderthals that consider
analog to be superior to (over-compressed) digital (as in the tube
audio fanatics). Perhaps one should save some of the analog test
equipment.


--
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
 

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