Toshiba TV29C90 problem; Image fades to black...

<runderwo@mail.win.org> wrote in message
news:1142381856.344175.108610@e56g2000cwe.googlegroups.com...
I'm not offended. It takes a lot to offend me. And I'm certainly not
going to be offended by someone who spends their free time helping
others for something they could charge money for. All I'm saying is
taking an unclear post, and from there jumping to conclusions about the
intelligence of the poster - instead of simply stating that the post
was unclear - is nothing more than noise. Posting nothing at all is
better than posting noise.

I guess I'm not going to get any more replies since I'm in everyone's
kill file by now. But I really didn't feel like the ad hominem attacks
were on target with respect to reaching a conclusion. Not that they
have to be - it's not my time they are wasting - but if the intent is
to convince me that I'm incompetent, I'm not interested, since I can
gauge my own level of competence and act (or not act) accordingly.
Click to expand...
I would doubt that you are in everyone's killfile - yet. But may I
respectfully ask that we just leave it as it is now. I'm sure we all
understand where you're coming from, and none of us wants to question your
intelligence. For the most part, from what I see in the many posts, it was
your expertise and competence to work on line powered equipment with a
degree of personal safety, that was being questioned, and I certainly don't
have a problem with that. I have no desire to help lead you to death or
injury. The reason that posters questioned your ability, was because you
were unable to recognise a type of fuseholder that has been used for many
years on all manner of equipment types - not just test equipment, but if
you've never had cause to work on such equipment, then fine, we will accept
that you were misled by a component that you didn't recognise, and not
question your competence, further.

Now, as I said before, calm down, forget about all the comments that you
considered to be at least unkind to you, if not offensive, put a new fuse
in, and tell us what happens. If it doesn't work, tell us, and we'll do our
best to help you.

Arfa
 
runderwo@mail.win.org writes:

I'm not offended. It takes a lot to offend me. And I'm certainly not
going to be offended by someone who spends their free time helping
others for something they could charge money for. All I'm saying is
taking an unclear post, and from there jumping to conclusions about the
intelligence of the poster - instead of simply stating that the post
was unclear - is nothing more than noise. Posting nothing at all is
better than posting noise.

I guess I'm not going to get any more replies since I'm in everyone's
kill file by now. But I really didn't feel like the ad hominem attacks
were on target with respect to reaching a conclusion. Not that they
have to be - it's not my time they are wasting - but if the intent is
to convince me that I'm incompetent, I'm not interested, since I can
gauge my own level of competence and act (or not act) accordingly.
Click to expand...
My only comment is that for someone to never have seen a fuse holder
like that means you have nver had the joy of working on older equipment
or industrial equipment. Those are the style fuse holder found in nearly
every non-consumer electronic equipment. If all you've dealt with are
computers, then perhaps not. But just do any kind of search on eBay,
for example, of "electronic equipment" and that's what you'll find.

--- sam | Sci.Electronics.Repair FAQ: 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 Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.
 
In article <1142381141.342637.160910@j33g2000cwa.googlegroups.com>,
runderwo@mail.win.org wrote:

I don't want to interrupt your outburst (heck we all have to let it out
at times), but let me point out several things:

1) Another poster posted a picture of a similar supply, which I
confirmed had the same type of fuse, and which I assumed everyone had
access to refer to. It was pointed out to me that not everyone has a
news reader configured to display inline images.

2) Why on earth would I have mistaken the holder for the fuse if there
were a fuse in it to begin with?

3) I can't buy the correct fuse locally. I either waste several
dollars on shipping for a single order, or I wait until I have a batch
of parts for several projects that I need to order.

4) I have "dabbled" in electronics for at least the past 15 years and
have never run across this type of fuse holder, ergo, at least one
statement regarding my lack of intelligence is false. "Electronics" is
a big and diverse field.

5) Apologies for the image link, but this is the fuse holder I am
talking about that I do in fact see in almost everything I have
repaired. I would be extremely surprised if you have not:
http://www.epn-online.com/images/editorial/33/11/P-11035.JPG
Click to expand...
Intelligence comes in many forms. If you know what a fuse does, that is,
connect two parts of a circuit, then you *should* have been able to tell
that the fuseholder wasn't doing that all by itself. That is a
particular form of intelligence called logic.

Also, if you know what a fuse does, and use logical, rational, problem
solving type of thinking, then you wouldn't jump to the conclusion that
a missing fuse equals a defective piece of equipment, particularly when
we're talking about a device that provides power to other things. It's
equally likely, if not more so, that whatever was last plugged into the
thing blew the fuse. Again, a failure of logic.

It's also possible that the last owner of the thing, uh, borrowed the
fuse for something that he needed more urgently.

I'm going to make you an offer. Delete the first h in my name, and send
me an email with your mailing address, and I'll send you a couple of
fuses at my expense. Then, perhaps, you can get to work doing whatever
you wanted to do with the thing in the first place.
 
Shawn@Thrillofthechase.biz wrote:
Hi all.

I have a large Viewsonic monitor.
Recently it started occasionally making a loud BANG sound and the
picture would freak out then come back to normal.
It did that for a few days and then just stopped working.
Is this repairable?
How expensive might it be?

Thanks
Shawn
Click to expand...

Without knowing the model number or having a crystal ball there's not
much we can tell you.
 
Sorry folks.
Not having any knowledge of electronics I did not know if this was a
common problem or not.
The model number is G810 made in 1999.
I've had no problems with it up until now.
I'll check out the troubleshooting site.

Thanks again.
Shawn
 
Do a google groups for the model G810 Viewsonic in this group for lots
of hits and one common problem with a fairly expensive part failure.

If you chose not to repair it, post your location here as someone might
take it for free so you won't have the hazardous waste disposal fees.
 
"Joust" <joust@microsoft.com> wrote in message
news:fdMRf.3060$fy1.178387@news20.bellglobal.com...
common problem
replace the DVD drive.
Click to expand...
Very ture about it being a common problem, but you can't just go out and buy
any dvd drive and put it in an xbox. You either have to buy a used xbox dvd
drive from someone or there is a dvd drive you can hack the crap out of and
make it work.. Looks like too much effort for me to try and have it not work
right. I'd look into getting a new optical assembly, but first I'd try
cleaning it.

-Mike
 
In article <1142391196.601886.28100@i39g2000cwa.googlegroups.com>,
alitonto@hotmail.com says...
I have seen some chargers that have the dropping resistor and LED in
series with each other and then this combination is in parallel with
another resistor of lower ohms which goes to the battery pack
Click to expand...
I assume your reason for considering this is to get a visual
indication that there is actually current flowing into the
battery. A reasonable thing to want, but...

Some of the makers who have done this have had trouble with
blowing out the LED's. Consider what happens when you plug
in a dead battery, or maybe even worse a bad one that happens
to be shorted...

If you have the room and can tolerate more parts, maybe
consider something like using the b-e junction of a power
transistor that can shrug off the worst case current and drive
the LED with a resistor off the collector.
 
"Ken G." <goodguyy@webtv.net> wrote in message
news:25085-441787F3-1876@storefull-3238.bay.webtv.net...
It wont read games but it will read & play a CD . I suppose the lazer is
shot .
Click to expand...
Try Cleaning the dvd drive.. If that doesn't work look into getting a new
optical assembly.. You have to find out what kind of dvd drive you have
first.. If it is a thompson here is a link to buy a new optical assembly

http://tinyurl.com/hgr6m

or

http://cgi.ebay.com/NEW-XBOX-THOMSON-LASER-LENS-COMPLETE-ASSEMBLY-PARTS_W0QQitemZ8257822096QQcategoryZ20385QQcmdZViewItem

Check out www.xbox-scene.com they have all kinds of info on xbox related
repair and etc..

- Mike
 
Thanks for promp reply. James,
does this mean that any resistor in series with the battery being
charged should have a voltage drop equal to the total voltage drop
across the LED and its dropping resistor?
Is it common to have a resistor (in series with the battery to be
charged) within all chargers?
(I haven't opened the charger yet)
Ali
 
hi there again!

Could anyone help me out this monitor?


NTC, model No: KM-411
The problem is low width and pincushion. It also has slight breathing.
I checked diodes, and transistors in the horizontal and pinamp area but

not found the culprit. Check coils by substitution but still no effect.

Comparing the voltage from a known good monitor, I discovered that this

one has low B+ output. Measured from flyback primary winding, the good
monitor has 200 volts. But the defective one has only 170 volts.
Anyway, I have tested capacitors with my ESR meter in the psu and
horizotal. They seem okay. Disconnecting flyback primary winding creeps

up the voltage to 215 volts. Does it mean the problem lies on the
horizontal section and not on the low voltage power supply section?
Where should I look now. It seems I'm lost.


Thanks in advance for troubleshooting tips.
ian

Ps. Ive reposted it so that other who may ran same problem be helped a
lot.

I've already found the problem. It's the
flyback (LOPT). Substituted it by a known good one and the set was
fixed. I
just dont know why flyback fails this way. I guess its defective
internally. Maybe partially shorted or open. I am not sure. Its because

when i disconnect the B+ supply in the primary winding of the flyback
before the problem was solved, the voltages in the horizontal section
creeps up to 200 volts.


So if someone encounters this problem, NTC, Model No: KM-411, if after
checking yokes, capacitors esr and capacitance and other components
especially in the low voltage psu and horiz section reveals nothing, a
big chance its the flyback breaking down when under load.
 
runderwo@mail.win.org writes:

Sam, save the flames for someone more deserving, please. I said that I
have never seen THIS TYPE of fuse before, because I mistook what is
apparently a broken fuse holder for the fuse itself. That is not
equivalent to asking "how do I test a fuse?". As for "questioning my
experience", go right ahead, I'm not going to get into a pissing match,
but it is usually less effort to simply answer the question as posed.

I openly admit that I rarely get to deal with nice test equipment. And
I don't see where that means that I should simply accept that it is
broken and not attempt to learn about it - just as I learned about
microwaves, televisions, monitors, amplifiers or any other piece of
electronics that could be dangerous if one does not employ common sense.
Click to expand...
Have it your way. You have been doing a great job of pissing off some
of the most helpful people on this newsgroup.

Enough said. :)

--- sam | Sci.Electronics.Repair FAQ: 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 Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.
 
I have a G810 in great condition I could sell you for $75+shipping. I'm
switching to LCD. Might be cheaper than the repair.

I think the latter post mentioning HV arch is probably your issue.

<mailto:marathonfl@hotmail.com>
-Brian
 
I recently acquired a Sansui T-80 am/fm tuner. The sound was pretty good,
but I had some flaky performance issues: The tuner would periodicaly lose
its' quartz-lock and the "tuned" inducator would drift badly. Also, the
entire digital display would periodically dim and lose some or all
functionality.

I opened up the case and first off noted that the main filter caps on the
power supply were leaky. Well, I figured, might as well bite the bullet and
replace all of the electrolytics given that this tuner was built in 1981.
So last night I replaced all 44 caps. I had trouble finding one of the spec
caps, a 0.15uF 100V electrolytic, and so ordered and installed two film caps
of this rating instead. All replacement caps matched the ratings of the
originals EXCEPT those 0.15uF caps... I think a previous owner had run into
the same problem with availability of this cap in an electrolytic and had
substituted a 0.22uF 100V.

I cleaned up the boards, put the whole unit back together and powered it up.
Well, first thing I noticed was the sound... low volume, tinny, no base at
all. Whereas before I started 25% volume on my amp would shake the house,
now I can easily go past 50% and still can't feel any thump in the floor.
The tuner drift issue has gone away, I suspect a cap labelled "AFC bias" was
the culprit there. However, I still have the dimming issue with the digital
display; perhaps the +5VDC regulator that powers the display board is flaky?
It's in a tough spot to blast with heat or cold without affecting a whole
whack of other components.

I left the tuner on all night thinking maybe there is some sort of initial
"burn-in" period and I THINK it sounded a bit better than at midnight last
night, but who knows...

Can anyone tell me where I might start to diagnose the tinny sound problem?
There are but a handful of coupling caps in the FM signal path, some in the
IF amp section, some adjacent to the MPX decoder. I am inclined to toss
back in the 0.22uF electrolytics that I replaced with film caps; they are
output coupling caps just to see what happens.

Any assistance greatly appreciated.

Dave
 
I have a Sony STR-D390 receiver -- circa 1992, digital tuner, drives 2 pair
speakers, has remote -- that (1) produces no sound except a very slight
hiss/buzz at full volume, (2) does not display "stereo" on startup when in
tuner mode tuned to an FM-stereo station and (3) has a dead tiny red light
in its motorized volume control knob.

All these symptoms began as an intermittent annoyance a few months ago,
always curable with a light tap or two on the chassis, then not-so-light
taps, then a couple good whacks, then hitting on it so hard the "logical"
next step was a sledgehammer. Good thing I don't have one.

Disconnecting everything and taking off the cover and gently poking around
I can find nothing obviously wrong -- solder joints look OK, no loose
components or broken wires or loose connectors. Does anyone out there have
any insights as to what the most likely problems would be and what a fix
would involve?

I have an old multitester and there are repair manuals available on line
but my skill/knowledge level got maxed out when they used vacuum tubes you
could take out and test at Radio Shack. Repair by Sony at their flat rate
would cost almost as much as buying a newer unit, and I'm trying to gather
what info I can before deciding to take it in for repair locally or
replacing it.

Thanks in advance from southern Wisconsin.
 
Pawel Paron wrote:
On 15.03.2006 Arfa Daily <arfa.daily@ntlworld.com> wrote:


As the unit is intended to use a super bright plasma discharge lamp, then a
low wattage halogen lamp will be no use at all, and you are probably just
seeing dust or minor anomalies in the optical path. Bear in mind also, that
the spectral composition of the light is rather different between plasma
lamps and incandescent halogen lamps. With the correct lamp fitted, it will
probably look fine.


Well, I considered that, but I doubt it would look good with a "real"
discharge lamp. This broken LCD or polariser (or whatever is broken) will
still pass this red light, as there is a lot of red wavelenght in the
spectrum of a discharge lamp. The problem is that the screen is not uniform.
Narrow upper part is perfectly fine, but it's getting bad towards left lower
corner. This does not depend on the bulb placement, or the angle of the
light beam that I direct into the projector optics. These red patterns are
fixed to the same position, so it's not an optical phenomenon in the lenses
or whatever, it really exists somewhere in the light path.

It's neither a permanent red-tinted burn into any optical piece, as when I
send a white test screen to the projector, there is almost uniform white
projection, so all three light channels can fully "open", but for some
reason the red channel canno't fully "close" in this irregular area, it
leaks it like you can see in the pictures. And there is that darker spot in
the middle of red bloch, looks like a centre of the damage, maybe this spot
was overheated? That's just my guess, so I'm looking for advices from more
experienced people, maybe it's some typical malfunction.


I can see why you would want to check it this way, as the cost of a
replacement lamp is ball-breakingly high, but if you're confident that this
is all that's required, and there is no problem with the ballast unit ( high
voltage generator for lamp start and run ), then you probably have no other
option but to go for it, and hope for the best. I'm actually quite surprised
though, that you've managed to get this far with testing, as normally, if
any problem is detected with the lamp, the system control puts the unit into
a full shutdown.


I "cheated" the projector, wiring a standard 400W MH bulb (big one, so it
was outside the projector) to the internal ballast, and supressing the
security switch. All circuits seem to be fine, lamp was working OK, no
problems with ballast or any other functionality, except this red light
blotching the major part of the screen.

Regards
Pawel
Click to expand...

Can you find someone with a similar projector and borrow the correct
lamp for testing? In a pinch you could buy a new lamp, then sell it if
it doesn't fix the problem.
 
Charlie Bress wrote:
I am working on an older HP Pavilion Model 6830.
The first complaint is that it would not turn on. I pressed the on switch
several times and it fired up.
Now it will not shut down. Even pulling out the line cord doesn't reset it.
Plug the cord back in and it is still on. The p/s is an ATX-105.

There is nothing else attached. No keyboard, no monitor. I am just going by
the sound of the fan and front panel LED.

The power on switch goes to the mobo through a connector. Unplugging this
connector and testing the switch it tests good for continuity. It is a
momentary contact switch which tells me that there is latch someplace. Is
this latch somewhere on the mobo or is it in the p/s itself?

Hold down the switch for five seconds or so....
Click to expand...

jak

Advice please.

Charlie
Click to expand...
 
Can you find someone with a similar projector and borrow the correct
lamp for testing? In a pinch you could buy a new lamp, then sell it if
it doesn't fix the problem.
Click to expand...
I already know, it's not a lamp issue, the polarizer is damaged (first one
from left):

http://acn.waw.pl/pawelp/projektor/3pol.jpg

Not that bad as I was expecting, I think I can replace it, at least it's
separate from the LCD.

Thanks everybody for responding.

Pawel
 
"Adrian C" <email@here.invalid> ???????:47qstqFgsc6fU1@individual.net...
wefixpcmotherboard wrote:
something is wrong with these capacitor in Socket 370 motherboar...while
using a multimeter:

top of two caps measure around +5.0 V

and one cap is measured at -9.0 V.

Hmmm... where does the negative connection to this cap go? If ground and
same manufacturer model/series as the other caps, then this part is either
reverse biased (and probably been inserted backwards), or you are
measuring an AC signal weighted with a strong negative component enough to
fool your meter!

Model/Name of motherboard, detected fault and general area of the cap's
location is useful to mention.

--
Adrian C
Click to expand...
the top of a cap is always metal. the normal rating is around 0.5V. When I
powered up the motherboard, only three of these caps have very strange
measurement.


all other caps have normal rating.
 
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