Toshiba TV29C90 problem; Image fades to black...

[Arfa Daily]

"Videlectrix" <bcgobraves@gmail.com> wrote in message
news:1165520681.497843.114230@16g2000cwy.googlegroups.com...

The side that the laser reads

Having repaired literally hundreds of the 3-player mechs in these over the
years, I really can't think of anywhere that this can be coming from. For it
to keep doing it, there would have to be a significant quantity of whatever
it is. I would have expected that, this being the case, you would have been
able to easily spot it. I'm assuming that whatever it is that gets on there,
is smeared around in a 'ring' on the disc ? Whilst the disc is on the
turntable, the only thing that comes close enough to the disc to thus
'spread' something that had been picked up as a spot whilst the disc was
being rotated on the carousel, is the lens. This being the case, you would
expect to then see something on the top of the lens after the event has
occured. Further, I would have expected the ring to be spread elsewhere on
the disc surface, by the passage of the lens across the disc - at least
until it had thinned it enough for the lens to no longer be able to touch
it.

There is actually very little grease used on this deck. The majority of the
open / close and sub-deck lifter gearing ( the blue gear, the black and
white gears, and the yellow rack slide ) are made from an oily plastic like
polythene, and run dry on their contact surfaces, although I seem to
remember that they might have silicone lubricant on their shafts. The only
other place that there is a significant quantity of grease, is on the
carousel worm drive, but this is located right underneath the tray, so I
can't see how any grease could get from there, onto the upper surface, where
it could get picked up by the disc.

It's a mystery, but one I would have thought that you could have got to the
bottom of by careful examination of the mech. If the contamination always
appears in the same place, then it should be an easy enough job to project
the band where it could be getting on the disc, onto the carousel, because
I'm sure that's where it *must* be getting on there, rather than from the
deck area, and then rotating the tray manually by working the worm gear with
a finger ( you can just get to it with the tray open ), and watching all the
way round, through one of the disc slots in the carousel. As I am very
familiar with this mech, I am most intrigued to know what it turns out to
be, so please share when you do find out.

Arfa

 

[William R. Walsh]

Hi!

1. What kind of waveform do they put out? Square wave?

Dunno for sure...I've seen references to modified sine wave units.

2. Is it possible to damage a piece of electronics using one? Plugging in
a radio, tv, laptop PC, what could the inverter do that would damage the
electronics?

Yes, it could be. I have a StatPower Portawattz (or something similar)
inverter that I bought reconditioned several years ago. The manual that came
with it had several things to say about this topic. I don't recall what all
was mentioned, but cordless drill chargers with notices printed about high
voltage present near the charging contacts were on it.

The only thing I've ever burned up or damaged on it was an X-10 remote
control module. (Don't ask. ) I've run computers, TV sets, box fans,
printers, clocks (with varying results in terms of clock accuracy), a stereo
receiver, laptop power bricks, and even a few lamps. They all worked
acceptably well.

3. If the electronics draws too many amps from the inverter, what will be
the result? Damaged inverter? Damaged electronics?

The inverter I have has been pretty good about this. It simply shuts down
with a loud beep and a red LED if it is overloaded or the battery voltage
falls below 10VDC. Any behavior is possible, but bad things generally
shouldn't happen. The worst case scenario that I'd consider acceptable would
be failure of a fuse in the inverter. Anything else failing inside it would
seem to indicate poor design.

William

 

[paragon66x]

If it seems to turn on normally, with the speaker relay coming on after the
usual delay, and just no display, there is a chance that only the -30 volt
line for the display is down (or some other section of the power supply).
There is a 100 ohm fusible resistor on the power board, R901, near the large
connector which goes to the main board. This resistor could be bad.

There is also a separate fuse board, and there could be bad fuses there -
don't recall if you said you had checked those.


Mark Z.

I actually checked the "hidden" fuses on the power supply board above
the transformer a while back. I went ahead and removed the power
supply from the stereo again tonight, removed the fuses again and they
checked ok for continuity. I then checked the resistors on the board
and they seemed to check within tolerance - one of these was the R901
you speak of. I went ahead and checked the switching diodes (they
seemed ok) and the two 1N002 diodes. One of the 1N002's (D902) tested
kind of odd so I pulled one leg out and it checks out the way it
should. When I put it back in the board it cheked out the same as
before across the ends - ".051" and it didn't matter which way I had
the black and red leads of my DMM. As you probably already know these
should ideally check between .4 - .6 one way and "OL" the other. So I
am not sure why this diode is reading this way, but I did notice one of
the traces is going to a small transistor Q901, but I do not recognize
this as one I know how to check/ meter out The numbers on it are C107
(top line) and M131 (bottom line). On the same trace going the other
way it leads to an OMRON 5VDC black box (not sure if its function).
Does this diode reading sound suspicious or like soemthing else on the
board is causing this goofy reading? Considering I pulled one leg out
and it read ok I beleive the diode to be good. Other than this, I
don't readily see anything that looks out of the ordinary. Any other
ideas for me to try? I will leave the power supply on my bench
overnight. Thanks for your help this far. John

 

[paragon66x]

Oh and as far as it turning on normally, I am not sure if I am
misleading you or not. The thing doesn't turn on. When you press the
power button it doesn't do jack. When you plug it in though it does
put power to the power button LED and it looks like there is fire going
to the cassette motor too as it lunges forward a bit. But that's all
she does other than make the click after plugging it in, but I don't
know what that click means - just seems like it always did that. John

 

[Meat Plow]

On Fri, 08 Dec 2006 10:47:01 -0800, fjp999 Has Frothed:

Hi all, looks like a great group here.

I have been using this one JVC S-VHS recorder for a number of years and
it may just be getting old.

I have been using it to record a 3 hour daily morning show. No problems
except for a few days ago.

The timer recording stopped before the three hours. I noticed it and
pressed the record button three times so that it would record for
another hour and automatically stop. I let it go and then noticed that
it stopped early as well.

The next day the three hour recording stopped at exactlly the same area
causing me to think that it was maybe a tape issue. I put in another
tape for the next mornings taping and it worked. I thought that was
that but then the next day (today) this tape also ended early by about
15 mins.

The first shut down tape of a few days ago, when played, would also
shut down the vcr at the area of the memory recording shut down. It
plays then makes a strange electrical vibration noise then shuts down.
I am playing todays tape and no shut downs at all - yet...

I am guessing that it is a serious problem and just need to find a new
machine.

thanks for any suggestions that might keep this one alive.
frank

Could be a belt, drive wheel, roller, etc.. ever fix one?

--
Pierre Salinger Memorial Hook, Line & Sinker, June 2004

COOSN-266-06-25794

 

[KarlB]

I don't know how close you are to your local TV transmitters, but I found I
can get a beautiful, clear HD picture from all three area network stations
on an old pair of UHF rabbit ears. I don't know how well that would work on
a VHF signal.


"Elle" <honda.lioness@nospam.earthlink.net> wrote in message
news:OaZdh.7787$sf5.3021@newsread4.news.pas.earthlink.net...

Thanks for all the suggestions, Jerry, RFI Guy, Charles, B, and T Shadow.
I'll keep studying and exploring this.

 

[fjp999]

Nope, never really had much luck with electronics and dont think I
could do well with these fingers.

The machine just played a 2.5 hour vid with no problems. Would these
issues be possible if it was playing with no trouble then have the
issues with the timer?

thanks for responding,
frank


Meat Plow wrote:

Could be a belt, drive wheel, roller, etc.. ever fix one?

--
Pierre Salinger Memorial Hook, Line & Sinker, June 2004

COOSN-266-06-25794

 

[Homer J Simpson]

"fjp999" <fjppaoh@yahoo.com> wrote in message
news:1165603621.163058.159510@j44g2000cwa.googlegroups.com...

The timer recording stopped before the three hours. I noticed it and
pressed the record button three times so that it would record for
another hour and automatically stop. I let it go and then noticed that
it stopped early as well.

Try a different brand of tape first.

 

[N Cook]

fjp999 <fjppaoh@yahoo.com> wrote in message
news:1165603621.163058.159510@j44g2000cwa.googlegroups.com...

Hi all, looks like a great group here.

I have been using this one JVC S-VHS recorder for a number of years and
it may just be getting old.

I have been using it to record a 3 hour daily morning show. No problems
except for a few days ago.

The timer recording stopped before the three hours. I noticed it and
pressed the record button three times so that it would record for
another hour and automatically stop. I let it go and then noticed that
it stopped early as well.

The next day the three hour recording stopped at exactlly the same area
causing me to think that it was maybe a tape issue. I put in another
tape for the next mornings taping and it worked. I thought that was
that but then the next day (today) this tape also ended early by about
15 mins.

The first shut down tape of a few days ago, when played, would also
shut down the vcr at the area of the memory recording shut down. It
plays then makes a strange electrical vibration noise then shuts down.
I am playing todays tape and no shut downs at all - yet...

I am guessing that it is a serious problem and just need to find a new
machine.

thanks for any suggestions that might keep this one alive.
frank

The start of the tape only has a small diameter to wind on to the spool,
as the tape progresses the diameter increases and the amount of torque
required from the drive motor increases. At some point if the slip clutch
slips too much or a drive belt slips then it will cease to rotate, reel
rotation sensor notices this and cuts the drive to avoid great loops of tape
in the cassette. Likely to be the same for playing the ends of tapes as
well.

VCR repair briefs on my file
http://www.divdev.fsnet.co.uk/repair.htm

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

 

in english:
also I have the same problem, black screen and the key power that it is
ignited and is extinguished. it could be the local power supply?

in italian:
anche io ho lo stesso problema ,schermo nero ed il tasto power che si
accende e si spegne. potrebbe essere l' alimentatore?

stuart2z9sl ha scritto:

To webpa:

Thanks for the info.
Had a feeling that it would not be something simple.
Did not cost much to begin with (ex Ebay) so not worth messing around
with.
Will bin it and buy a new one - NOT Ebay.

Thanks again
Regards - Stuart


--
stuart2z9sl
------------------------------------------------------------------------
stuart2z9sl's Profile: http://www.futurehardware.in/member.php?userid=176
View this thread: http://www.futurehardware.in/showthread.php?t=547628

Future Hardware - http://www.futurehardware.in

 

[Mark D. Zacharias]

paragon66x wrote:

If it seems to turn on normally, with the speaker relay coming on
after the usual delay, and just no display, there is a chance that
only the -30 volt line for the display is down (or some other
section of the power supply). There is a 100 ohm fusible resistor on
the power board, R901, near the large connector which goes to the
main board. This resistor could be bad.

There is also a separate fuse board, and there could be bad fuses
there - don't recall if you said you had checked those.


Mark Z.

I actually checked the "hidden" fuses on the power supply board above
the transformer a while back. I went ahead and removed the power
supply from the stereo again tonight, removed the fuses again and they
checked ok for continuity. I then checked the resistors on the board
and they seemed to check within tolerance - one of these was the R901
you speak of. I went ahead and checked the switching diodes (they
seemed ok) and the two 1N002 diodes. One of the 1N002's (D902) tested
kind of odd so I pulled one leg out and it checks out the way it
should. When I put it back in the board it cheked out the same as
before across the ends - ".051" and it didn't matter which way I had
the black and red leads of my DMM. As you probably already know these
should ideally check between .4 - .6 one way and "OL" the other. So I
am not sure why this diode is reading this way, but I did notice one
of the traces is going to a small transistor Q901, but I do not
recognize this as one I know how to check/ meter out The numbers on
it are C107 (top line) and M131 (bottom line). On the same trace
going the other way it leads to an OMRON 5VDC black box (not sure if
its function). Does this diode reading sound suspicious or like
soemthing else on the board is causing this goofy reading?
Considering I pulled one leg out and it read ok I beleive the diode
to be good. Other than this, I don't readily see anything that looks
out of the ordinary. Any other ideas for me to try? I will leave
the power supply on my bench overnight. Thanks for your help this
far. John

Well, sorry we got off track. These models can be tough sometimes (well,
most of the time it seems).

Generally speaking - one must confirm the standby status first. The DC
voltage derived from the standby transformer, usually 5 volts. The reset
line to the microprocessor should rise smoothly and pretty quick from 0 to 5
volts when the power cord is inserted. The crystal should be running. If no
scope is available, the DC voltage on the crystal should be about 1/2 of the
5 volts. There would be a relay turn-on line from the micro which obviously
should fire when you press the power button.

I'm concerned about that relay firing when you plug it in, though - doesn't
sound right to me.

Although your model is somewhat different, there is a history I should make
you aware of.

On the HCD-GX450 and 250 models there was an issue with the flat cable which
connected the main board on the side with the front panel. Somehow even
though these were new units, sometimes there were bad or intermittent
connections where this cable plugged in, both at the main board and at the
front panel side. Caused a variety of unusual symptoms INCLUDING one I saw
where the relay fired upon plugging in, but would not turn on.

Sound familiar?

Mark Z.

 

[fjp999]

Thanks everyone for their suggestions.

I have another tape in the machine which gave me the same problem
yesterday but not today. Got my three hours as instructed. And yes the
machine is set to record EP as I am already getting over two hours even
when it doesnt respond accurately.

Anyways, will mark this somewhat resolved, by itself, but will come
back for more suggestions if, cross ones fingers, that it ever returns.

thanks again all,
frank



Homer J Simpson wrote:

"fjp999" <fjppaoh@yahoo.com> wrote in message
news:1165603621.163058.159510@j44g2000cwa.googlegroups.com...

The timer recording stopped before the three hours. I noticed it and
pressed the record button three times so that it would record for
another hour and automatically stop. I let it go and then noticed that
it stopped early as well.

Try a different brand of tape first.

 

[Homer J Simpson]

"fjp999" <fjppaoh@yahoo.com> wrote in message
news:1165697728.583868.282240@f1g2000cwa.googlegroups.com...

I have another tape in the machine which gave me the same problem
yesterday but not today. Got my three hours as instructed. And yes the
machine is set to record EP as I am already getting over two hours even
when it doesnt respond accurately.

I have many tapes which play and wind fine while one from the same batch
won't rewind and stops while recording. Some are just bad.

 

[coffee]

On Sat, 09 Dec 2006 12:16:49 -0600, jakdedert wrote:

coffee wrote:
This is a shot in the dark but just thought I would ask.

Ive got a NEC MT1040 projector that needs to be calibrated. I understand
that special software is needed to do this. I also understand that its
proprietary software from NEC.

My problem is that my colors are off. I think its called convergence. The
projector displays several colored lines instead of just one line.

Anyone have any idea how to repair this myself or on the cheap?

Thanks,

In many (all?) projectors, this is a matter of *physically* aligning the
three separate lcd panels. I'm not aware of any which can be aligned
electronically.

Has the projector been dropped?

jak

Wasnt dropped. The previous owner wanted to clean the projector and
removed some boards from the inside and reseated them. Im assuming that
this wipped out some information stored in them and now the projectors
colors are out of alignment.

This is the first time messing around with projectors. I dont have alot of
experience with them but Iam experienced in electronics.

He was telling me that he wanted to clean some dust out of the inside and
had an other person come over. They removed some circuit boards from the
inside and after they reseated them the picture was off. He went into the
settings on the projector but couldnt fix the problem.

The only thing that I have been able to dig up is the service guild on the
projector and it mentions software needed to "recalibrate" the projector.
Even gives the program needed:

(cut from pdf service guild)
Equipment to be used and working environment
<Equipment to be used>
ˇ Servicing adjustment software (Ser_99mt.exe Ver1.0)
Attached files: V-T Data, etc.
ˇ Personal computer [which allows Windows95 or Windows3.1 to operate and the serial port (COM1 or COM2
or COM3) is of the D-SUB9pin.]

(end of qoute)

It mentions "Ghost control" and was thinking that might be what Im
interested in correcting.

You know, Any help you can provide on the subject would be fantastic. I
just cannot believe that such a device would have to be sent in for repair
because the software is not available or not released for the general
public to use to calibrate it.

--
Thanks,

Coffee

 

[coffee]

On Sat, 09 Dec 2006 23:55:38 -0500, coffee wrote:

On Sat, 09 Dec 2006 12:16:49 -0600, jakdedert wrote:

coffee wrote:
This is a shot in the dark but just thought I would ask.

Ive got a NEC MT1040 projector that needs to be calibrated. I understand
that special software is needed to do this. I also understand that its
proprietary software from NEC.

My problem is that my colors are off. I think its called convergence. The
projector displays several colored lines instead of just one line.

Anyone have any idea how to repair this myself or on the cheap?

Thanks,

In many (all?) projectors, this is a matter of *physically* aligning the
three separate lcd panels. I'm not aware of any which can be aligned
electronically.

Has the projector been dropped?

jak

Wasnt dropped. The previous owner wanted to clean the projector and
removed some boards from the inside and reseated them. Im assuming that
this wipped out some information stored in them and now the projectors
colors are out of alignment.

This is the first time messing around with projectors. I dont have alot of
experience with them but Iam experienced in electronics.

He was telling me that he wanted to clean some dust out of the inside and
had an other person come over. They removed some circuit boards from the
inside and after they reseated them the picture was off. He went into the
settings on the projector but couldnt fix the problem.

The only thing that I have been able to dig up is the service guild on the
projector and it mentions software needed to "recalibrate" the projector.
Even gives the program needed:

(cut from pdf service guild)
Equipment to be used and working environment
Equipment to be used
ˇ Servicing adjustment software (Ser_99mt.exe Ver1.0)
Attached files: V-T Data, etc.
ˇ Personal computer [which allows Windows95 or Windows3.1 to operate and the serial port (COM1 or COM2
or COM3) is of the D-SUB9pin.]

(end of qoute)

It mentions "Ghost control" and was thinking that might be what Im
interested in correcting.

You know, Any help you can provide on the subject would be fantastic. I
just cannot believe that such a device would have to be sent in for repair
because the software is not available or not released for the general
public to use to calibrate it.

Im going to look into adjustment of the "lcd panels" that you talked about.

I dont see them mentioned in the service guild but maybe they are called
something else instead. Just like IBM calls a printhead on a laser printer
a "ROS Assembly". <grin>.


--
Thanks,

Coffee

 

[Jake]

Jim Land (NO SPAM) wrote:

"Jake" <gl1000gold@yahoo.com> wrote in news:1165436075.632350.204050@
80g2000cwy.googlegroups.com:

hello all, I've been searching for a schematic for a VT VR-140 Guitar
Equalizer amp from he 70's I've tried just about everywhere and I'm now
seeking information here. I'd really like to get it back up and see
what it sounds like so if anyone here has a schematic please let me
know.

Google is your friend.

http://www.musicparts.com/products.asp?Company=Vibration%20Technology

Twenty bucks.

Thanks for the link, I managed to get the manual really apprichiate
your reply

Thanks Jim K

 

[nobody@anywhere.com]

On 3 Dec 2006 18:00:26 -0800, "tombates@city-net.com"
<tombates@city-net.com> wrote:

I hope this is the correct place to ask this question. I notice that
some new stereos come with a USB connection. I am trying to figure out
the purpose of it. I have visited a number of electronic stores and
asked, but I keep getting different answers. Is the USB to connect a
MP3 player, so you can play the songs from your MP3 player on your
stereo? Is the USB to connect your computer to your stereo, so you can
use the speakers on your stereo for music being played on your
computer? This would mean both would need to be in the same room which
would not make any sense, but maybe so. Is the USB used to connect a
flash or thumbdrive which contains MP3 files which you can then play on
your stereo? This is the reason I would be interested. Anyone have any
idea what is the real answer? I probably should take my flash drive
next time, and plug it in the see if it works.

Thanks

Tom

Some MP3 players rechage via USB, so perhaps the port is to
recharge/power the player when connected to your stereo? I notice alot
of car cig invertors now come with 120v outlets and usb ports too.

 

[Arfa Daily]

"Not me" <nobody@anywhere.com> wrote in message
news:51hnn2h5doa4c6q76ktq1bip7nqtj7lt9a@4ax.com...

On 3 Dec 2006 18:00:26 -0800, "tombates@city-net.com"
tombates@city-net.com> wrote:

I hope this is the correct place to ask this question. I notice that
some new stereos come with a USB connection. I am trying to figure out
the purpose of it. I have visited a number of electronic stores and
asked, but I keep getting different answers. Is the USB to connect a
MP3 player, so you can play the songs from your MP3 player on your
stereo? Is the USB to connect your computer to your stereo, so you can
use the speakers on your stereo for music being played on your
computer? This would mean both would need to be in the same room which
would not make any sense, but maybe so. Is the USB used to connect a
flash or thumbdrive which contains MP3 files which you can then play on
your stereo? This is the reason I would be interested. Anyone have any
idea what is the real answer? I probably should take my flash drive
next time, and plug it in the see if it works.

Thanks

Tom

Some MP3 players rechage via USB, so perhaps the port is to
recharge/power the player when connected to your stereo? I notice alot
of car cig invertors now come with 120v outlets and usb ports too.

The port would still have to be useable as a data-carrying USB though,

unless you are going to use the headphone output socket to connect the audio
to the system, which would be pretty pointless ??

Arfa

 

[george]

Michael

Great idea. Unfortunately the nomad has windows3.1 on it so no joy
there. Thanks.

George

Michael Kennedy wrote:

If you happen to be runing windows on this maching, you can use direct cable
connection to connect two computers with a null-modem cable with the serial
ports or the LPT printer ports.

Example
http://kb.iu.edu/data/ahcj.html


- Mike

 

[David Naylor]

Elle wrote:

My ten-year-old television's display is mighty snowy much of
the time (when receiving local channels), until I give it a
good whack and I guess cause some connections to work
properly again. It's humongous and so hard to move by
myself. I am getting old and do not want to have to move it.
Rather than try to repair it, I am thinking of buying a new,
lighter, flat screen TV. I have been keeping an eye peeled
for specials at Circuit City, Best Buy, and Wal-Mart. I
looked at the latest Consumer Reports article on the
subject.

Yesterday at Best Buy a clerk there said buying any of the
flat screen TVs meant I would have HDTV. Without cable or
satellite with HD, the display would have black vertical
bars covering something like three inches on both sides. If
I wanted to continue using an ordinary antenna, I'd have to
go to a conventional TV with a 4:3 aspect ratio.

Can someone please confirm or deny what the clerk said and
maybe elaborate? Meanwhile I am googling on the subject.

I do not want cable or satellite or any extra costs. OTOH, I
also do not want a huge television to move around.

TIA


go by the philips 32mf231d/37 and when you get is set up the aspect to

automatice.. and if your using an antenna youe will recieve your local
chanels in HD you will love that set..I work on those at a bb service
center and go crazy every time i see the picture it is unblieveable