Toshiba TV29C90 problem; Image fades to black...

[kony]

On Tue, 19 Oct 2004 16:09:44 +0100, Franklin
<no_thanks@mail.com> wrote:

On 17 Oct 2004, Chip wrote:


"David Maynard" <dNOTmayn@ev1.net> wrote in message
news:10n3k1osh82u7f3@corp.supernews.com...
[...]

"OK"? Well sort of. The idea that you have a "550W" PSU with a
maximum 12V supply of 14A I would say is "sharp practise" at
best, and fraud at worst.

The 35A on the +5V line might save them?

Huh?

"Output current +5V [A] 25A (Sticker 30A)"

Compare to name-brand 400W units that can sustain 40A 5V.

 

[Sofie]

Hey... "Dude" Marc:
Yes there are several makes and models of DVD Recorder/VHS combo units that
allow recording from VHS to DVD and visa-versa. Check out the following
link:
http://hometheater.about.com/od/dvdhardwareandsoftware/tp/dvdvcrrecorders.htm
So Dude Marc....... I hope you found this helpful and please give the
salesperson at the National Electronics chain store a break..... flipping
hamburgers and selling electronics are noble employment opportunities.....
and he appeared to be well informed as the website link above indicates.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -



"Marc" <dbacks@attglobal.net> wrote in message >

Bill, do I understand your post correctly?

You want a combo unit to record a vhs onto a dvd?

I have never seen a combo unit that records from a vhs to a dvd.

If you have seen such a unit, maybe you can post the brand and model
number on this ng, and we can all learn something from that info.

But, as I suspect, there might have been a "salesperson" at a national
electronics chain store, who's favorite word was "DUDE" that may have
misinformed you about a product.

You need to take into account that this salesperson has only a few
remaining active brain cells, and was flipping hamburgers only a
couple of weeks ago for minimum wage...(Peter Principle)

And now, just because he works for a "major" national chain store, he
is an "expert" on all subjects relating to audio/visual.

 

[Chuck Harris]

numcrun wrote:

I have tried it on another player, as I said in the post, and it
played fine. So I don't think it's defective mastering.

Once apon a time, back when DVD players were very expensive, and
relatively rare, there was a website that did comparisons of the
accuracy with which different players rendered certain media.

Well, most were pretty good, but each had a problem with some
test DVD or another. I know "The Big Lebowski" was one of the
test DVD's, and I seem to recall that "La Dolca Vita" was another.

The test DVDs were chosen for their ability to screw up the
various rendering programs.

-Chuck Harris

 

[john]

Dont use a Generic in this Model it will FRY.

kip

 

[N Cook]

"Theo" <theodore.twyler@ntlworld.com> wrote in message
news:4Qcdd.586$mT.456@newsfe6-gui.ntli.net...

The main problem with modern 'motion' detectors is the gravitic anomalyser
adjuster fitted to the differential time constant manipulator within the
self repricating interoscittor biasing network. The flux indicating
squelch
controller tends to supersaturate with binary fluctuations in the temporal
memory latch, producing negative
feedback nodes within the positive regeneration diplexer.

I couldn't have put it better myself

 

[Chuck Harris]

james@nospam.com wrote:

Let's have a show of hands.... How many really find a curve tracer to be
a piece of test equipment you use regularly and would dearly miss if you
didn't have one.


I remember the first time I used a curve tracer at work. Took me a
long time to realize that little line running out past 12 volts was
the whole show.

Later on, I got cheap kicks watching the temps scratching their heads
after hours of sitting in front of the Tek with the ludicrous
operation manual open next to them.

The books for the Tek 577/177 are sure a piece of .... work.
They don't even have one example of how to trace a transistor, and
have it survive... I guess you are just supposed to know.

Did anyone ever write a decent book explaining how to get the
most out of the Tek curve tracers?

-Chuck Harris

OBTW, I have used my 577/177 more for tracing tubes than for tracing transistors.

 

[LASERandDVDfan]

I have tried it on another player, as I said in the post, and it
played fine. So I don't think it's defective mastering.

Check to see if there is a default language settings in the player's setup
menu.

This menu sets the player to automatically select which soundtrack and which
subtitles by default when playing without going through the menu. - Reinhart

 

[ldservice]

Hi David,

I just worked on one of these today, same problem. The mechanical
transport is Sony, optics as in the MDP-605. The problem with this unit
appears to be a failure of the mode switch, which then allows the optics
to run all the way into the spindle motor, bending the objective lens and
causing a severe focus problem. No focus, no spin. Replaced the optics,
serviced the mode switch and all is OK.

Duncan

 

[syale]

Daniel, would you have the service manual and scematic for this set. I am
an amateur electronic hobbyist and have fixed two televisions so far. I
have this set donated to me and want to find out where the test voltage
points and values are. I can hear the transformer hum on but have no
picture.

Stephen Yale

 

[James Sweet]

If you're just starting out, just go to Radio Shack or whatever similar
place near you and pick up a basic 25w-35w soldering iron, once you get more
skilled you might wish to look into something better.


"Marc" <dbacks@attglobal.net> wrote in message
news:20e8027b.0410190656.3cb30262@posting.google.com...

OK, here is where I could really use the assistance of experienced
technical types.

I have an interest in electronics, but I am not proficient at
soldering.

I need advice on soldering tools: irons, solder, etc (I do have a
variac to regulate the iron)

Brand names, wattage, etc,

Part numbers...

solder, with or without rosin...

ANYTHING...

Thank you in advance for your help.

Marc

 

[Chuck Harris]

James Sweet wrote:

If you're just starting out, just go to Radio Shack or whatever similar
place near you and pick up a basic 25w-35w soldering iron, once you get more
skilled you might wish to look into something better.

You are much more likely to become "more skilled" if you start
with the best iron you can afford. There isn't much excuse for
not using a temperature controlled soldering station these days.
I have seen them on sale for as low as $40 for a no name chinese
make unit.

-Chuck

 

[James Sweet]

"Henry Markov" <jnhblhr@yahoo.com> wrote in message
news:41741AC8.3C76A53C@yahoo.com...

A few things occurred to me immediately after posting. You may not have
enough
memory to run XP (although BartPE is a reduced XP) and XP may not run on a
386.
It's possible that you would have neither restriction with Knoppix
(Linux).

XP won't run on a 386, nor is it likely to work on a 486. Even on a 133-233
MHx Pentium it'll be painfully slow and unuseable with any less than 128MB.

 

First bit of advice is to buy a decent regulated soldering iron.
Using a variac doesn't really give you a controlled temp. Decent
fixed temp irons can be had for $30.

-Chris


On 19 Oct 2004 07:56:59 -0700, dbacks@attglobal.net (Marc) wrote:

OK, here is where I could really use the assistance of experienced
technical types.

I have an interest in electronics, but I am not proficient at
soldering.

I need advice on soldering tools: irons, solder, etc (I do have a
variac to regulate the iron)

Brand names, wattage, etc,

Part numbers...

solder, with or without rosin...

ANYTHING...

Thank you in advance for your help.

Marc

 

[Jerry G.]

When the HOT is shorted out, this can be from a drive problem, or there
is a defective flyback, and or there are defective components on the
output side of the flyback. Very often in this series of set, I found
the flyback had to be changed, and or there were problems in the drives
from the scan gen circuits to the HOT. If the HOT is shorted, there is a
good chance that some damage to the power supply may have also occurred.

Considering the age of the set, there is a strong possibility, that
there will be many electrolytic caps that have become high in ESR from
their age.

To service the set, you will have to work one step at a time until you
resolve all the issues in each area. This is something that cannot be
predicted over an email.

I would not look at servicing a TV set a good way to learn electronics.
You will gain only some familiarity of how TV sets are built, but not
really a strong learning of the detailed theory of how they and their
circuits operate.

--

Jerry G.
======

"Marc" <dbacks@attglobal.net> wrote in message
news:20e8027b.0410190626.59ff68d3@posting.google.com...
I recently acquired a non-working Sony KV-2780R television
manufactured in 1987.

I know nothing of the history of this television, but it was one step
away from the dump...and is an excellent candidate for educational
purposes...(aka FREE!)

I pulled the back off, and checked the main fuse, it was ok.

I plugged it in, and turned it on. I could hear the "on" circuit come
on, but no sound or picture.

I then unplugged it and began taking a closer look at the video
circuitry.

(the audio portion of the circuitry appears to be contained on a
separate board,
probably modular, and probably used on several different models of
televisions)

The only "clean" area on the video circuit board was a
heatsink/transistor sub-assembly located just in front of the flyback
transformer.

The heatsink/transistor sub-assembly was just sitting there, loose,
de-soldered from the board. (all three of the transistor leads, as
well as the heatsink mountings were de-soldered from the board)

The transistor (D1497) is shorted out.

My guess is this: that a repair technician checked the set, and
determined that, at the very least, the HOT was bad, and the overall
cost of the repair was too expensive, so the television was not
repaired.

Here is my question:

When the HOT is determined to be shorted, is this symptomatic of a
larger problem???

Possibly other parts down stream or up stream (so to speak) shorting?

Again, any and all help is appreciated,

Thanks,

Mark

 

[Jerry G.]

The amplifier is going in to protect mode, because one or more of the
output devices is shorted, or biased to pull too much current, and or
there is DC at the output. You will have to change the output devices,
and their associated drivers to verify this. Driver transistors can be
easily checked. Usually in these amplifiers the driver and pre-driver
stages are DC coupled. Check in the schematic to know for sure.

--

Jerry G.
======

"Perion" <RazroRog@hotmail.com> wrote in message
news:SfKdnY7On_qak-jcRVn-qA@comcast.com...
If anyone is REAL bored maybe you could print this out, have a look at
the
schematic at (pdf) at
http://mywebpages.comcast.net/dharp/files/str_se501/STR_DE515.pdf . It's
the
closest I can find to my str-se501 - the amplifier section is real close
to what
I have. See page 2 - at about G21. [All 5 of my ch. amps are like the
top
three - I don't have IC601 or IC651]

Here's the deal:
1. It goes into protect mode - duh....

2. All the speaker relays for each channel are energized.

3. Center channel is reading full supply voltage (sum of B+ and B- vs.
just B+
or B- like all the other channels) on each of its output transistors
from
collector to base! The other channels have near zero vdc on the base and
B+ or
B- from base to collector. Getting B+ to the base of Q553 and B- to the
base of
Q554). Also, output xistor resistances different than other four
channels.

4. Removed both center ch transistors. Still goes into protect mode.
Traced
where opposite supply voltages on the bases back to STL350-230 center
channel
driver IC. The other 4 channels all read the same and have identical
static ckt.
resistances - they are driven from uPC2581 driver ICs. Probably explains
why
center ch. reading different resistances than other four.

5. Removed the STK350-230 center ch. driver IC. No more weird voltage
readings
at the output xistors' solder points. On the STK350-230 IC I was getting
B+ on
pin 6 (+VEOUT) to the base of the Q553 and B- on pin 5 (-VEOUT) to the
base of
the Q554 which seems crap to me - maybe I'm wrong. Anyway, it still goes
into
protect mode.

6. Can't find anything else that doesn't seem right on any of the
channels.

Question:
1. Any brilliant insights into this?
2. If it goes into protect mode, shouldn't at least one of the channel's
amp
over load detect transistors (like Q570) be turned on and inhibit that
amp's
associated speaker relay?
3. Down at R6 (the signals to the display board) it seems to get its
"protect
in" signal (24) from the "OC Offset DET" (overcurrent detector?) at D25.
It
looks to me like this monitors each channel's over load detectors so
again, if
in protect mode, shouldn't at least one channel's overload detector be
turned?
4. Do I have to do something special to reset protect mode other than
power down
and back up?

thanks,
Perion

 

[Art]

Have you done any basic diagnostics, such as check if the H_output is not
shorted or if there are viable standby voltages being generated??
"syale" <stephen.yale@gmail.com> wrote in message
news:93a1196142755fc894e15719fb9d7c79@localhost.talkaboutelectronicequipment.com...

Daniel, would you have the service manual and scematic for this set. I am
an amateur electronic hobbyist and have fixed two televisions so far. I
have this set donated to me and want to find out where the test voltage
points and values are. I can hear the transformer hum on but have no
picture.

Stephen Yale

 

[Chuck Harris]

Norm Dresner wrote:

you off like that, I'd hate to be around you if somebody spilled wine on
your white jacket!! Woohoooooooooo

--


I do make a distinction between true accidents and intentional acts that are
not necessary. Playing music when I visit a site is not an accident. It's
intentional! And it's damned annoying to me. It doesn't matter why. It's
my office, my desk, my computer and my ears. And it's damned annoying. To
me.

If the site had a prominent button to turn the music off, I'd never have
complained. But it doesn't.

Norm

It doesn't need to, you have that power within your browser. If you don't
like sites that play music, remove the plugin that plays music.

-Chuck

 

[Tom MacIntyre]

On Sat, 16 Oct 2004 15:27:08 GMT, Tom MacIntyre
<tom__macintyre@hotmail.com> wrote:

On Sat, 16 Oct 2004 12:27:14 GMT, Ken <user@domain.invalid> wrote:

Wizard of Ozz wrote:
I'm using Windows 98 and I just bought a new monitor, a Samsung
SyncMaster 793s 17" screen. My old one was a Samsung Syncmaster 3 14"
screen.

When I went to change the monitor type on the Active Desktop list of
monitors, it obviously didn't have the newer 793s, so I tried to pick
a standardized monitor type from the list (at the top of the list it
says "standard monitor types").

I'm stuck between 2 options:
Super VGA 1024x768
Super VGA 1024x768 at 75 Hz

How can I tell which one I should pick? Also, does it matter if I
continue to use the monitor with the setting wrongly selected for the
older Syncmaster 3? What does this setting change, anyhow?

I should also note that the CD that came with the monitor only
provided drivers for Win2000 and up to Win XP, but not for Win 95/98.

Did the monitor not come with some software drivers? If not, you might
visit the maker's website and see if some are not available. Normally
you will have many possible settings if you acquire the proper drivers.

You may have some luck with whatever the newer Samsung drivers are
that are available with Windows also, but compare specs to yours
before you change anything. If you do make a change and lose your
screen, restart in Safe Mode (F5 or F* while booting).

....make that F5 or F8.

Tom

 

[Chuck Harris]

Jacques Carrier wrote:

You are much more likely to become "more skilled" if you start
with the best iron you can afford. There isn't much excuse for
not using a temperature controlled soldering station these days.
I have seen them on sale for as low as $40 for a no name chinese
make unit.

-Chuck



I would buy a good (Weller) temperature controlled station and avoid Radio Shack
and Chinese made equipment.You get what you pay for...........save now and......
repent later........

Jacques

I would too, but then, I use my iron to make a living.

There are some terrific deals on soldering stations to be had
on ebay. Soldering stations are kind of like used shoes and
beds; hard to sell.

-Chuck

 

[robertg]

Speaker info....Thanks very much!

Robert