Toshiba TV29C90 problem; Image fades to black...

[JW]

On 20 Nov 2006 05:18:53 -0800 "Sarah" <SCSH123@hotmail.com> wrote in
Message id: <1164028733.662682.6650@m73g2000cwd.googlegroups.com>:

Hello, can anyone help with what to do if certain DVDs don't play on my
Dell Inspiron 640m laptop. VCDs and some DVDs ok. Thanks! Sarah

Have you checked the region code of both the DVD and the DVD player to see
if they match? The region code of your DVD player can be accessed (and
changed, but only 5 times IIRC) in the device manager under advanced
settings for the drive. See:
See http://hometheater.about.com/cs/dvdlaserdisc/a/aaregioncodesa.htm

 

[R!]

wrongaddress@att.net wrote in
news:1163387574.804150.266160@h54g2000cwb.googlegroups.com:

I have an old 8 gernamium transistor, protable AM radio that is noisy
on weak stations when cold. It works reasonably well when set it in
the sunshine and warms up. The problem seems to be the RF section
since the noise goes away when the volume is turned down. I'm
suspecting the germanium transistors may be the problem and wondering
which one might be replaced with a silicon variety to cure the
temperature problems?

I'm not sure what all 8 transistors do. Two are in the output stage,
and another is used as a audio driver that drives the audio input
transformer.There are four RF coils, the usual oscillator (red) and
mixer (yellow) and white (1st IF) and (black (second IF). But that
only requires 6 transistors, and there are eight total. The detector
is a diode, so they didn't use a transistor for that. I haven't
figured out what the other 2 transistors do.

I'm thinking of replacing the oscillator transistor with a high gain
silicon variety to try and eliminate the temperature problems?

Any other ideas?

-Bill

I was just thinking are you shure it is the oscillator ?

Tune near the bottom of the band take another radio and try to tune to
the oscillator probably 455Kcs above tuned frequency, listen for a dead
spot with a little background noise, that changes when the dial is
rocked slightly on the defective radio. Do this while the radio works
then chill it and see if you can still tune the oscillator or not,
don't
change the dial on the now cold radio.

I had a problem similar to this and it was a bad IF transformer
worked fair when warm got worse as temperature droped and guit
completely at aproximately 25 deg. F.

If it worked with gernamium transistors at one time when the defect is
repaired it should function without major modifications, which would be
necessary with the change to silicon transistors.

Hope you understand what I am saying.

R!

 

Hi all,

I got a Fluke 97Scopemeter, ...
I am looking for the service manual ...Philips/Fluke no longer sell it. Here's a scan of my own:
http://www.users.on.net/~fzabkar/PM97/

Thanks a lot Franc, very appreciated!!!

Obviously my Scopemeter is faulty. Now with the service manual I'm
trying to find out what's wrong with mine.

Looking for repair info on usenet i've seen that there are a lot of
people with the same symptoms... dead lcd but ICs correctly supplied
with 5V.

Maybe a common failure? Did someone has found a solution?


Thanks
Bye
Federico

- invert my username from my address when replying by email.

 

[reqluq]

"b" <reverend_rogers@yahoo.com> wrote in message
news:1163417185.310025.311060@h48g2000cwc.googlegroups.com...

joanneo0322@hotmail.com ha escrito:

CHICAGO - A small study suggests that eating dark chocolate can lower
your blood pressure
- a delicious instance in which something that tastes good might, for a
change, be good for
you, too.

http://www.chocolatebite.blogspot.com

koko

please don't post this on here. this is for electronics repair.

But this might apply here; shhesh sometimes trying to fix things can run my
blood pressure up, it's nice to know that a bite of choco is good for the
palate and the ol' pressure; and thus good for the heart

So, here's the connection: Electroincs repair=high blood pressure=eat dark
chocolate=lower blood pressure=repair electronics.
So I'd say it's a valid post hehe.
req

 

[Jim Land]

"R!" <hobbob123@mailinator.com> wrote in news:1164112908.770760
@nnrp1.phx1.gblx.net:

I had a problem similar to this and it was a bad IF transformer
worked fair when warm got worse as temperature droped and guit
completely at aproximately 25 deg. F.

How did you figure out it was the IF transformer? And did you figure what
was wrong with the IF transformer? I mean, gee, what could go wrong with
an IF transformer that would vary with temperature?

 

[James Sweet]

Jim Land wrote:

"R!" <hobbob123@mailinator.com> wrote in news:1164112908.770760
@nnrp1.phx1.gblx.net:


I had a problem similar to this and it was a bad IF transformer
worked fair when warm got worse as temperature droped and guit
completely at aproximately 25 deg. F.


How did you figure out it was the IF transformer? And did you figure what
was wrong with the IF transformer? I mean, gee, what could go wrong with
an IF transformer that would vary with temperature?

Broken winding I suppose, or worn through insulation causing a shorted turn.

 

[R!]

Jim Land <RrrrFfffTttt(NO)@(SPAM)hotmail.com> wrote in
news:Xns9882A71FBADDCRrrrFfffTttt4396hotm@216.168.3.44:

"R!" <hobbob123@mailinator.com> wrote in news:1164112908.770760
@nnrp1.phx1.gblx.net:

I had a problem similar to this and it was a bad IF transformer
worked fair when warm got worse as temperature droped and guit
completely at aproximately 25 deg. F.

How did you figure out it was the IF transformer? And did you figure
what was wrong with the IF transformer? I mean, gee, what could go
wrong with an IF transformer that would vary with temperature?

The IF transformer has some really small capacitors in their base, one
of the capacitors developed leakage that varied with temperature.

I use an old radio to find problems such as this. Make a removable
connection at the detector circuit in a working radio and use it for a
signal tracer. The connection contains a .01uf capacitor in series as
well as a 100k resistor near the end used for a probe. Connect chassis
together for ground return, sometimes the + side of the power supply.

R!

 

[Jumpster Jiver]

bz wrote:

Jumpster Jiver <me@no.spam.today> wrote in news:45620E6A.3020902
@no.spam.today:


Sarah wrote:

Hello, can anyone help with what to do if certain DVDs don't play on my
Dell Inspiron 640m laptop. VCDs and some DVDs ok. Thanks! Sarah


First check that you have the latest drivers, and reinstall if necessary.
However... chances are the drive is bad. If you are able to
disassemble it you can try cleaning the lens, but your best bet is to
replace the drive.
You can buy any brand drive - it doesn't have to be dell brand.


I think you missed the fact that it is a laptop computer.

1) She doesn't need to disassemble in order to clean the lense.
2) It is unlikely that another brand drive will fit. It is even unlikely
that the drive from another model dell will fit.
She COULD get an external drive.
She could check with dell for price of a replacement drive
She could look for a junker of the same model and hope the cd drive is
good.

Oops, I did miss that. Silly since I'm typing on an Inspiron right now.

 

I concurr!!

On Nov 21, 8:29 pm, "reqluq" <scredcropshonnos...@hotmail.com> wrote:

"b" <reverend_rog...@yahoo.com> wrote in messagenews:1163417185.310025.311060@h48g2000cwc.googlegroups.com...



joanneo0...@hotmail.com ha escrito:

CHICAGO - A small study suggests that eating dark chocolate can lower
your blood pressure
- a delicious instance in which something that tastes good might, for a
change, be good for
you, too.

http://www.chocolatebite.blogspot.com

koko

please don't post this on here. this is for electronics repair.But this might apply here; shhesh sometimes trying to fix things can run my
blood pressure up, it's nice to know that a bite of choco is good for the
palate and the ol' pressure; and thus good for the heart

So, here's the connection: Electroincs repair=high blood pressure=eat dark
chocolate=lower blood pressure=repair electronics.
So I'd say it's a valid post hehe.
req

 

[Art]

Jason: Happy Thanksgiving!!
Check for poor solder connections at the inter board connectors, common
problem. Also the DCU, the item within the metal box tyo are tappin on has a
plugin connector where it plugs into the main board. Possible bad
connections there or an actual problem inthe DCU itself. The interboard
cpnnectors have been a concern, those form the main signal to the deflection
and those from the deflection onto the convergence power amp board. They are
a pain to access, requiring removal of the pc boards and a good mag glass.
"Jason D." <depotcon@kos.net> wrote in message
news:4563407e.12425794@news.kos.net...

Knocking on STK392-110 no result, but knocking on the metal can box
for convergence generator makes little noise lines in the picture,
also bit different results if I knock around on the signal mainboard.

Is there any known issues with 51SWX20B convergence problems?

While ago we had to replace that convergence generator box on a older
Hitachi. This convergence generator box is located under the CRTs in
middle on the "floor" of cabinet for very intermittent extreme pulling
apart at tune of 400 for this tiny box, replacing caps did not repair
this.

Cheers, Wizard

 

[nonya damnbizness]

Make sure you have the latest codecs installed
http://www.free-codecs.com/download/K_Lite_Mega_Codec_Pack.htm


"JW" <none@dev.nul> wrote in message
news:qal5m212bctjvijotk7t10gsr55dn0dv2n@4ax.com...

On 20 Nov 2006 05:18:53 -0800 "Sarah" <SCSH123@hotmail.com> wrote in
Message id: <1164028733.662682.6650@m73g2000cwd.googlegroups.com>:

Hello, can anyone help with what to do if certain DVDs don't play on my
Dell Inspiron 640m laptop. VCDs and some DVDs ok. Thanks! Sarah

Have you checked the region code of both the DVD and the DVD player to see
if they match? The region code of your DVD player can be accessed (and
changed, but only 5 times IIRC) in the device manager under advanced
settings for the drive. See:
See http://hometheater.about.com/cs/dvdlaserdisc/a/aaregioncodesa.htm

 

[Jim Land]

"Simoc" <simoc@suomi24.fi> wrote in news:1164217441.280032.134440
@e3g2000cwe.googlegroups.com:

I got Technics 323 tuner amp, which is lacking a volume pot. It has
balance adjustment on the same knob, too. The knob came with it, it has
a "head" and "sleeve" which both have the same radius, and have no
space between them.

So might the balance adjustment be done so that the "head" just adjusts
one channel and the sleeve the other, and thus their ratio could be
adjusted, and when the volume is adjusted, both of them (ie. the entire
knob) are turned same amount?

What might be the name of the pot of such kind (a stereo pot having the
both channels separately adjustable?)

Then there is one more problem. There is a 5-wire ribbon cable for
connection of the pot...what might be the pinout? Or if anyone doesn't
know, how could I analyze it with a scope maybe? It just cannot be
easily done by analyzing the circuit, since the mainboard is very
complex and has a lot of stuff above it, and the device hasn't a
detachable bottom, so disassembling for analyzing the circuit would be
quite an infernal job...:

So the unit arrived missing a pot? Better get the service manual, which
is easily available, according to Google:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=9719888771&category=
64610

Then you'll have a clue to the wiring, and will know the part number for
the pot and can look for one. Some parts for this model are available
from

http://www.partstore.com

and if you're very, very lucky, they might have the pot you need. Good
luck!

 

[David Naylor]

ghamilton99@gmail.com wrote:

I have a Toshiba TP50H15 with a power supply shutdown problem, The -18V
overcurrent is tripping the sutdown circuit (found some power supply
functional detail on the web) I cannot get any fruther without the
rest of the schematic. Can you provide any help?
Any clues or suggestions would be appreciated.

Thanks very much
G. Hamilton

one of your convergance amp ics has gone south these are the large stk

ic located on the large heat sink there are to side by side look for
1 or 2 blown resistors and change out the ic's and the blown 2.2 ohm
resitors very common problem in projo's

 

[b]

Arfa Daily ha escrito:

Hi

Has anyone got schematics for an Aiwa MX-Z9500MK that they could either have
a look at for me, or scan ? Need to know how the VFD filament supply is
derived - and before everyone rushes to say " I think it's via a cap ", in
this Aiwa model, it's not.

Thanks

Arfa

have you tried eserviceinfo?

 

[Arfa Daily]

"b" <reverend_rogers@yahoo.com> wrote in message
news:1164233121.094084.21630@k70g2000cwa.googlegroups.com...

Arfa Daily ha escrito:

Hi

Has anyone got schematics for an Aiwa MX-Z9500MK that they could either
have
a look at for me, or scan ? Need to know how the VFD filament supply is
derived - and before everyone rushes to say " I think it's via a cap ",
in
this Aiwa model, it's not.

Thanks

Nothing listed for this model. I'm not desperate, as the system is not worth
that much, but as it was apart on the bench, and I had sorted the
missing -24v problem, it was a bit annoying that I still had trouble with
the filament supply. This appears to be switched with a couple of
transistors near to the -24v reg. They actually derive the -24 on this
model, direct from a rectifier, rather than by the more traditional Aiwa
voltage multiplier. I don't really know why they bother switching the
filament supply to unused displays when the unit is off. Possibly to
preserve their life, I guess, but I have seen plenty of units where the
filament supply is always on. Anyway, having found these transistors, I went
looking for a control signal, but I couldn't find anything in the area that
moved when you switched from standby to on. There is a little surface mount
digital transistor that looks as though it ought to control this lot, and
what should be the base leg, has print disappearing off towards the front
panel, but as I say, no movement of voltages around it. Just for sport, I
tried shorting across the switch transistor, and this immediately restored
filament volts, and display on the amp, but still no filament volts up the
bus to the graphic, so that remained dead. That was the point that I called
it a day, and posted the request just to see if anyone had a manual.

No matter though, I have wrapped it back up now, and told the shop that
booked it in that the only way that it is going ahead, is if a service
manual could be found. They have indicated that they don't think that their
customer will want to be bothered, so it will finish up now as just another
of those jobs that end up only just about covering their time ... Thanks for
the suggestion anyway.

Arfa

Arfa

have you tried eserviceinfo?

 

[N Cook]

Simoc <simoc@suomi24.fi> wrote in message
news:1164217569.182181.260600@m73g2000cwd.googlegroups.com...

Hi!

Does anyone here know how to adjust height of the tape (the tilted
guide posts) in Philips TurboDrive VR 232 / 13 ? There seem not to be
any screws or nuts on those guide posts, they can even be easily
detached as they're attached by plastic detachable parts. But I don't
find a way to do the adjustment

--
Top-posting not supported.

Why would you want to adjust the angled tape guides?
If they don't slide and lock into the V end stops then a problem with the
linkages/tensioner.
The repair manual for the 232/13 has the details for other tape guide
adjustments.
NB. If you should go into the test modes then one of the settings is for
erasing the contents of the EEprom

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

 

[Simoc]

N Cook wrote:

Why would you want to adjust the angled tape guides?
If they don't slide and lock into the V end stops then a problem with the
linkages/tensioner.

They're against V-stoppers, but the tape path seems to be misaligned. I
must admit that I'm still not very familiar with VCR mechanics, but
I've read about VCR repair from repairfaq.org, and according to it, the
height adjustment is done by the angled guides, isn't it?

The repair manual for the 232/13 has the details for other tape guide
adjustments.

Of course, but I probably can't get it without paying, can I?

--
> Top-posting not supported.

 

[Simoc]

N Cook wrote:

Why would you want to adjust the angled tape guides?
If they don't slide and lock into the V end stops then a problem with the
linkages/tensioner.

They're against V-stoppers, but the tape path seems to be misaligned. I
must admit that I'm still not very familiar with VCR mechanics, but
I've read about VCR repair from repairfaq.org, and according to it, the
height adjustment is done by the angled guides, isn't it?

The repair manual for the 232/13 has the details for other tape guide
adjustments.

Of course, but I probably can't get it without paying, can I?

--
Top-posting not supported.

 

[b]

Arfa Daily ha escrito:

"b" <reverend_rogers@yahoo.com> wrote in message
news:1164233121.094084.21630@k70g2000cwa.googlegroups.com...

Arfa Daily ha escrito:

Hi

Has anyone got schematics for an Aiwa MX-Z9500MK that they could either
have
a look at for me, or scan ? Need to know how the VFD filament supply is
derived - and before everyone rushes to say " I think it's via a cap ",
in
this Aiwa model, it's not.

Thanks


Nothing listed for this model. I'm not desperate, as the system is not worth
that much, but as it was apart on the bench, and I had sorted the
missing -24v problem, it was a bit annoying that I still had trouble with
the filament supply. This appears to be switched with a couple of
transistors near to the -24v reg. They actually derive the -24 on this
model, direct from a rectifier, rather than by the more traditional Aiwa
voltage multiplier. I don't really know why they bother switching the
filament supply to unused displays when the unit is off. Possibly to
preserve their life, I guess, but I have seen plenty of units where the
filament supply is always on. Anyway, having found these transistors, I went
looking for a control signal, but I couldn't find anything in the area that
moved when you switched from standby to on. There is a little surface mount
digital transistor that looks as though it ought to control this lot, and
what should be the base leg, has print disappearing off towards the front
panel, but as I say, no movement of voltages around it. Just for sport, I
tried shorting across the switch transistor, and this immediately restored
filament volts, and display on the amp, but still no filament volts up the
bus to the graphic, so that remained dead. That was the point that I called
it a day, and posted the request just to see if anyone had a manual.

No matter though, I have wrapped it back up now, and told the shop that
booked it in that the only way that it is going ahead, is if a service
manual could be found. They have indicated that they don't think that their
customer will want to be bothered, so it will finish up now as just another
of those jobs that end up only just about covering their time ... Thanks for
the suggestion anyway.

Arfa

I've generally found mini systems horrible things to work on. if it's
not dismantling the thing to access the front bit, its the awful audio
output stages and board layout etc. Often, for anything more
complicated than cap replacement, mechanical or electro- mechanical
stuff, a service manual seems to be the order of the day.....
good luck
-B

 

[Mark D. Zacharias]

Simoc wrote:

N Cook wrote:

Why would you want to adjust the angled tape guides?
If they don't slide and lock into the V end stops then a problem
with the linkages/tensioner.

They're against V-stoppers, but the tape path seems to be misaligned.
I must admit that I'm still not very familiar with VCR mechanics, but
I've read about VCR repair from repairfaq.org, and according to it,
the height adjustment is done by the angled guides, isn't it?

The repair manual for the 232/13 has the details for other tape guide
adjustments.

Of course, but I probably can't get it without paying, can I?

First of all, what problem are you having? If the playback picture is
jittery or rolling, alignment might help. Severe misalignment would show a
number of horizontal bars of snow.

The slanted posts are not adjusted, the height of the rollers is. A slotted
flat blade screwdriver is usually required. Older models have set screws
which must be loosened somewhat for the adjustment, then re-tightened. Newer
ones generally just have some tension built-in so that the post does not
rotate easily on it's own.

It's best by far to use an oscilloscope to make the adjustments, but I'm
assuming you don't have one...

You could try using a known good tape, then adjusting the entrance roller a
bit each way, and try to center it in the area of most stable playback. Same
eith the exit roller.

Mark Z.