Toshiba TV29C90 problem; Image fades to black...

"TEX" <TEX@Nospam.com> wrote in message news:41c509ee@news.iconz.co.nz...
| I have had another look and there is a proper posistor (black box with
| three legs), this thing I am having probs identifying looks like a large
| disc ceramic capacitor. Black in color. Has the markings 15D15. Runs
| inline with the fuse.

Inline with the whole set?

N
 
NSM wrote:

"TEX" <TEX@Nospam.com> wrote in message news:41c509ee@news.iconz.co.nz...
| I have had another look and there is a proper posistor (black box with
| three legs), this thing I am having probs identifying looks like a large
| disc ceramic capacitor. Black in color. Has the markings 15D15. Runs
| inline with the fuse.

Inline with the whole set?

N


Yeah. it runs in series straight after the main fuse on the live trace.
Click to expand...
It looks like it might be a heater or something? It measures 23ohms
across it, even with a chunk missing from it. Any more help??

Thanks

TEX
 
"TEX" <TEX@Nospam.com> wrote in message news:41c51add$1@news.iconz.co.nz...
| NSM wrote:

| > Inline with the whole set?
| >
| > N
| >
| >
| Yeah. it runs in series straight after the main fuse on the live trace.
| It looks like it might be a heater or something? It measures 23ohms
| across it, even with a chunk missing from it. Any more help??
|
| Thanks
|
| TEX

Maybe a soft start device? Seems odd, since I assume this has a SMPS.

N
 
"TEX" <TEX@Nospam.com> wrote in message news:41c51add$1@news.iconz.co.nz...
NSM wrote:

"TEX" <TEX@Nospam.com> wrote in message
news:41c509ee@news.iconz.co.nz...
| I have had another look and there is a proper posistor (black box with
| three legs), this thing I am having probs identifying looks like a
large
| disc ceramic capacitor. Black in color. Has the markings 15D15. Runs
| inline with the fuse.

Inline with the whole set?

N


Yeah. it runs in series straight after the main fuse on the live trace.
It looks like it might be a heater or something? It measures 23ohms
across it, even with a chunk missing from it. Any more help??

Thanks
Click to expand...

Sounds like a posistor to limit the inrush current when the mail filter
capacitor charges, the resistance drops as it warms up. They're often used
when the power supply is software controlled to prevent the current spike
from damaging the triac controlling the power.
 
Thanks for that James. That is what I thought, one posistor for the
degauss (the back box type with the three legs) and one for the software
power on (the disc ceramic looking one with two legs). I have put back
in anyway, but the psu is still doing the same thing....not doing anything.

Gonna have to check if the standby voltages are present, otherwise just
convert the silly thing to a PC ATX power supply and mod it to a new case.

Thanks

TEX


James Sweet wrote:

"TEX" <TEX@Nospam.com> wrote in message news:41c51add$1@news.iconz.co.nz...

NSM wrote:


"TEX" <TEX@Nospam.com> wrote in message

news:41c509ee@news.iconz.co.nz...

| I have had another look and there is a proper posistor (black box with
| three legs), this thing I am having probs identifying looks like a

large

| disc ceramic capacitor. Black in color. Has the markings 15D15. Runs
| inline with the fuse.

Inline with the whole set?

N



Yeah. it runs in series straight after the main fuse on the live trace.
It looks like it might be a heater or something? It measures 23ohms
across it, even with a chunk missing from it. Any more help??

Thanks



Sounds like a posistor to limit the inrush current when the mail filter
capacitor charges, the resistance drops as it warms up. They're often used
when the power supply is software controlled to prevent the current spike
from damaging the triac controlling the power.
Click to expand...
 
James Sweet wrote:
"NSM" <nowrite@to.me> wrote in message news:F37xd.5807$KO5.1825@clgrps13...

"Damian Menscher" <menscher+usenet@uiuc.edu> wrote in message
news:cq2t33$vl6$1@news.ks.uiuc.edu...

| Thanks to you and everyone else for the advice. I'll certainly think
| more carefully about this (and probably just use a real HV probe).

If you ever have any doubts about the power of electricity, watch the
episode of "The Beverly Hillbillies" where the bear eats granny's love
letter and Jethro comes up with a plan to X-ray the bear.

N




I would hardly think Beverly Hillbillies to be a good source of information
on electricity safety, anything in a TV show like that is pure fabrication,
it may coincide with real life but no more likely than what any random
person would assume to be true.
Click to expand...
Great analogy to newsgroups.

Yes, THIS is one of the better groups.
Some very smart people hang out here.
Some of them know what they're talking about.
Some of those have RELEVANT practical experience.
Some of those can communicate.

Multiply all those factors to get and indication of the
signal to noise ratio. Maybe we should call it the
newsgroup Hillbilly factor.

If you already know the right answer to
your question, you can often find it in the thread.
But if you already know the wrong answer, it's probably
in there too. Sigh!
mike
--
Return address is VALID.
Wanted, Slot 1 Motherboard
500MHz Tek DSOscilloscope TDS540 Make Offer
http://nm7u.tripod.com/homepage/te.html
Wanted, 12.1" LCD for Gateway Solo 5300. Samsung LT121SU-121
Bunch of stuff For Sale and Wanted at the link below.
http://www.geocities.com/SiliconValley/Monitor/4710/
 
Check for dry joints on the outputs and on the boards.
If you dont want to fix it I will take it off your hands.
lol

kip
 
The coil that I was referring to may not affect the picture. I think
you may have other issues if audio modulation is affecting your video.
As far as your color problem if the cable signal and the DVD is fine I
would suspect a VCR problem. Lenny Stein, Barlen Electronics.
 
"Asimov" <Asimov@-removethis-bbs.juxtaposition.dynip.com> wrote in message
news:MSGID_1=3a167=2f133.0_41c510ea@fidonet.org...
"NSM" bravely wrote to "All" (18 Dec 04 19:13:08)
--- on the heady topic of "Re: Magnetic sheilding"

What are you thinking, man?! Aluminum is about as good as a piece of
paper in holding any magnetic flux. Perhaps something easily found
like galvanized sheet steel is more likely to work if placed in close
proximity to the device to protect and grounded (to avoid static build
up). Even something like a metal shelf might work but then there is
always the problem of the colour purity being thrown out of whack.

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Take a video tape degausser and hold it close to a sheet of aluminium (or
copper). Note what happens. Physics theory will now tell you that the
conductive material is not 'amplifying or enhancing' the magnetic field.
Think it through.

Remember, the OP was looking for 'cheap enough to try'. That does not
include 6 foot squares of 1/4" mild steel plate.

N
 
<archersteven@yahoo.com> wrote in message
news:1103474571.784409.130380@c13g2000cwb.googlegroups.com...
| My 5 year old Sony DA30 ES reciever has taken to having the overload
| protector kick in when I turn it on. If I keep cycling it (which I
| know is bad for it) I can eventually get it to kick in and then it's
| fine. Any one have any ideas on a fix or what's causing it? I am
| going to take it out of the cabinet today to blow it out since it looks
| to be very dusty. Don't know if that could have anything to do with
| it.
|
| I know how to work a multimeter and some basic electronics knowlege
| from my intro EE clases
|
| Is a DA30ES een worth fixing if it's not simple?

I'd tend to assume a main filter capacitor is reluctant to form. The
cheapest 'fix' is to never turn it off.

N
 
"t.hoehler" <t.hoehler@insightbb.com> wrote in message
news:6Xixd.220160$V41.34442@attbi_s52...

| My brother in law was in on the design and prep for production for the
ced.
| He had already worked with the Japanese engineers on the RCA Selectavision
| VHS machines. He said the step from the very, very sophisticated
| electromechanical vcr to the ced system was like going from LP's back to
the
| cylinder phonograph. I saw some ced video demo at a Radio Shack in the
| eighties, not too bad, but knowing what a kludgey mechanical system it was
| kept me away from it.
| Tom

In 1982 the video quality of the Radio Shack/Hitachi and these disks was
much better than the VCRs of that time. But look at how many variations of
media we have had with the same content: 35mm and 16mm film, VHS, Beta, CED,
Laser Disk and now DVD. What's next, crystal cubes?

N
 
In 1982 the video quality of the Radio Shack/Hitachi and these disks was
much better than the VCRs of that time. But look at how many variations of
media we have had with the same content: 35mm and 16mm film, VHS, Beta,
CED,
Laser Disk and now DVD. What's next, crystal cubes?

N
Click to expand...
Supposedly DVD using a blue laser, allowing much higher data density. Once
they get the recordable/re-writable thing down solid and the price of
recorders and media drops to something acceptable I think VHS will all but
dissapear and we'll be with a DVD technology of some sort for at least as
long as VHS has stuck around. Even without recording ability, DVD has taken
the market by storm, I've never seen a new technology take hold so quickly,
it spread like wildfire. It works, very well, and it's cheap. I'm sure it'll
be around for a while.
 
Harry Hotspur <harryHotspur@freeserve.co.uk> wrote:
Anyway when I powered it up next, I found that (what it looks like) the
posistor has blown and spat all over the case. I suspect it is a
posistor as it runs in series with the fuse and is close to the degauss
coil. It is actually soldered on a set of pins exactly like the ones you
would normally plug the degauss coil.
It's the Degauss posistor,always seem to pop,they are only pennies to
buy and any TV shop will have them or close enough to run as the
degauss specs are not critical,don't run without it,buy a couple.
Click to expand...
From the description above it sounds more like the NTC resistor that is
in series with the power supply to reduce inrush current.

---
Met vriendelijke groet,

Maarten Bakker.
 
ok...ill sawp in another VCR and see what happens. Also the slight
picture interferance is fine by me, as long as i can get the audio
cleared up (or do you think both problems are linked?) Ill work on
adjusting the coils this week like i said and Ill let you know the
result.

Thanks again,
Keith
 
Are you a technician or otherwise able to read a schematic?

Mark Z.


<tuffhand@yahoo.com> wrote in message
news:CZoxd.598976$D%.489406@attbi_s51...
Does anyone have a service manual for this receiver? Mine goes into
protect
mode as soon as it powers up.

Thank you.
Click to expand...
 
<tuffhand@yahoo.com> wrote in message
news:CZoxd.598976$D%.489406@attbi_s51...
Does anyone have a service manual for this receiver? Mine goes into
protect
mode as soon as it powers up.

Thank you.
Click to expand...
A service manual probably isn't much use for this, chances are some/all of
the output devices are blown, basic audio amplifier troubleshooting applies.
 
Mothra wrote:

I have a car stereo front panel (model: Panasonic CQ-DFX572N mp3 player)
in which the display suddenly stopped working the other day.

I'm not much of an electronics buff, but on opening it carefully, I can
see that there is a large plastic backlight (presumably an LED?) the
size height and width of the whole front panel that sits behind an LCD
'mask' which then lets through the blue light to display the text,
giving a blue text on black background effect. The blue backlight also
liights up some front panel buttons and the area around the volume knob.
The only front panel light the currently works is a red one, and
therefore must have its own LED/backlight.

I plugged the naked circuit board into the car stereo head unit and saw
that the LCD screen still works, it's just the backlight that is broken.

I can see what I'm sure are the the two solder points on the back of the
PCB that correpsond to the backlight. They look OK, although by that I
mean the solder points don't seem to be loose or dirty.

So all that's broken is the backlight.

Questions:

Are these types of backlights just LEDS?

Do they normally have fuses, is this what might have blown?

Is this easily fixable, is there anything I can try given that a new
front panel is almost the same cost as a completely new stereo?
Click to expand...
You probably have a EL display. No, there NOT leds. They take a higher
voltage to make them work. Typically 40 to 100 volts.
If there is a higher voltage at the terminals and its dead, the display is
bad. If not, the power inverter the supplies the display is bad.

Bob



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that usually works great for me also, i went through my oldsmobile and
changed them, its strange that they still use typical bulbs in these
devices when led lamps will outlast the device and use much less current
(they do it for cell phone displays), i guess that is just the "built to
die" principle that manufacturers use these days. if just one stereo
manufacturer would really build consumer level electronics and design them
well it seems to me that they would take over the consumer electronics
market anyways im rambling , if you want to use led lamps you can go to a
hoopers parts supplier if one is nearby and the led package should give
you the resistance you should use in a 12v system. the cheapest way i
found to get a good bright white led is to get one of those keychain
lights for about $4 or go to http://www.superbrightleds.com/ and you can
order them
 
i would hate to attempt a hard drive repair, was the adapter to make the
smaller laptop drive connect to the ide cable professionally made? try to
wipe out you bios and reset the settings its a long shot but sometimes it
works, the motor in the drive will spin as long as the power supply is
connected usually. if the drive is toast because of power into the data
lines and the m/b not bad feel lucky and go buy a new hd, if your data is
extremely important and your hd still being made, go buy the exact same
drive and change controller boards
 
Every one I ever ordered (been a while) came with the entire upper cylinder and
heads as a complete assy...
 
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