Toshiba TV29C90 problem; Image fades to black...

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?

Advice please.

Charlie
Click to expand...
I've seen this problem a few times caused by bad electrolytic capacitors
in the power supply. Often the PSU is just replaced though, unless it's
a high end one it probably isn't really worth fixing unless you just
want the challenge.
 
wefixpcmotherboard wrote:
the top of a cap is always metal.
Click to expand...
You KNOW you can get motherboards serviced by the manufacturer, or if
cheap enough toss 'em.

--
Adrian C
 
Bill -

Let me offer my most heartfelt thanks for publishing the Battery FAQ. I
am an electrical engineer, and I find that the whole arena of lead-acid
batteries is one of the most misunderstood topics I have encountered.
Problem is, it SEEMS so simple, and there is so much mis-information and
pure BS advertising hype out there, that everybody and his brother
thinks they understand it, and that they are experts.

I belong to a Solar Power Forum where this problem arises quite
regularly. People invest tens of thousands of dollars in their systems,
and then beat the hell out of their batteries, and wonder what went
wrong. I am pleased to be able to quote a bit of knowledge from your
site, and then add a link to the rest of it. When I do, I can almost
hear the ethereal sigh "Ooooh, so that's what happens! That's how it
works!"

Bill Jeffrey
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Bill Darden wrote:

Hi all,

The Car and Deep Cycle Battery FAQ has been updated. The current
version is 5.4, dated February 26, 2006 and can be found on
www.batteryfaq.org. Answers to Frequently Asked Questions, tips,
manufacturer's information, references and hyperlinks are contained on
this free, consumer oriented Web site about car, motorcycle, power
sports, truck, boat, marine, recreational vehicle, solar, and other
starting and deep cycle applications.

The most popular sections in February were:

Battery Manufacturers and Brand Names List

FAQ Section 9 HOW DO I CHARGE (OR EQUALIZE) MY BATTERY?

Section 7 WHAT DO I LOOK FOR IN BUYING A NEW BATTERY?

Battery Information Links List

Section 4 HOW DO I TEST A BATTERY?

If you have time, please visit www.batteryfaq.org. If not please
bookmark it for future reference. Questions, comments and suggestions
for improvement are always welcome at info@batteryfaq.org.

Many thanks and kindest regards,

BiLL.....
Click to expand...
 
Smitty Two wrote:
In article <dv9kdc$h1m$1@news.doit.wisc.edu>, Bob <no@spam.org> wrote:

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.

Look here, my good fellow from Wisconsin, spotting a cracked solder
joint often requires heaping quantities of magnification and lights
bright enough to toast marshmallows. Don't be tellin' me there's no
cracked joints if you haven't surveyed that thing at 10x on a high
rooftop at noon. Even then it's likely you'll have to wiggle suspicious
components to see the crack.
I agree...... You definitely have a bad solder joint. Check devices that
Click to expand...
generate heat first. Sometimes you just have to resolder all joints to
find the faulty one.

Newfdog
 
<captainvideo462002@yahoo.com> wrote in message
news:1142445107.874278.126800@v46g2000cwv.googlegroups.com...
I replaced two noisey intermittent preamp transistors in one channel of
this unit with NTE324's. These are supposed to be a direct replacement
for the originals. The unit seems to work well. All transistors in both
channels under quiescent conditions seem to run cool enough and there
is no noticeable distortion when driving the amps at sufficient volume.
However I have noticed that after a few minutes at sustained loud
volume the complementary output transistors on the repaired channel
seem to be running noticeably warmer than the other. They are nowhere
near "alarmingly" warm but just enough to let me know that there is a
difference. I have taken some comparative voltage measurements between
both channels and as expected have noted some differences. I have
attempted to tweak the bias pot on the repaired channel to even things
out between the two channels but it seemes like for instance if I
adjust the pot so that the emitter on one of the outputs matches the
same transistor on the the other channel it throws sonmething else off.
Should I just go for 0volts at the midpoint of the two outputs at the
big inductor or might there be more to it than that? Without the
service manual I don't know where to make the measuremenrt or what to
adjust it for. This appears to be a direct coupled amp with 4A fuses to
the speakers and without a capacitor on the output. I've seen
amplifiers of this type destroy speakers before so I don't want to make
a mistake with this. Can anyone advise me further. Thanks for any
assistance. Lenny Stein, Barlen Electronics.
Click to expand...
Measure across the emitter resistors with no load. Adjust for the same as
the other channel. If the heating difference re-appears with a load, there's
a dc offset, maybe a small one but it can make a difference in effective
bias.

Mark Z.
 
forget Google there is a guy on ebay that sells the thompson drives new
for 24.95 i think just search for the xbox replacement drive....
comes from canada unless you can do better than 24.95 for a new drive


Michael Kennedy wrote:
wow.. all I had seen in the past was how to hack a pc drive to make it
work.. but after a quick google I found a real xbox dvd drive..
http://store.richspsxparts.com/xbthdvddr.html

"James Sweet" <jamessweet@hotmail.com> wrote in message
news:WuZRf.18084$wH5.5618@trnddc02...

Ken G. wrote:

It wont read games but it will read & play a CD . I suppose the lazer is
shot .



The DVD drive has failed, there's places that sell replacements, I don't
have a link on hand but Google should turn something up, just look for
Xbox DVD replacement.
Click to expand...
 
Michael Kennedy wrote:
I've put an air compressor togeather with a tank.. I have one problem
though.. Once the tank is pressurized and the compressor shuts off
there isn't a leak down for the air pump. I have a checkvalve between
the compressor and the tank but I need some sort of pressure release
for the compressor pump itself so when it shuts down it will release
pressure.. If you don't release the pressure the motor cant start the
air pump.. There is just too much backpressure on it.

Does anybody know what I can do to remedy this problem other than
leave the fittings loose?

Thanks,

- Mike
Click to expand...
Also check out the pressure switches, there should be some that have a small
valve (like an auto tyre valve) that bleeds off the discharge line when the
switch goes open at pressure.

--
Regards ......... Rheilly Phoull
 
Thus spake Rheilly Phoull:

Also check out the pressure switches, there should be some that have a small
valve (like an auto tyre valve) that bleeds off the discharge line when the
switch goes open at pressure.
Click to expand...
Automatic pressure switches for compressors are available with and without
pressure "blow-off" valves. When the motor contactor releases at the pre-set
pressure, there is a little lever that opens the blow-off vavle releasing the
pressure between tank and pump.

Good luck,
--
DaveC
me@privacy.net
This is an invalid return address
Please reply in the news group
 
Hello,


I have a Sony KV-A2921D (chassis AE-1C...i think). The problem is that
it shuts off after een few seconds when turned on with the main switch.
It goes like: TV goes on, the tube is static, the LED blinks 4 times
(fast) and then the TV shuts off/goes in protection.
I found some information on the web, about replacing the C605, C608,
C611 and the C617. So I did. After that the TV worked for aprox 15
minutes and returned to the same problem.

Can some help me fixing this problem??? Because the picture is still
good when the TV works.


Thanks in advance.
Jantje
 
Or cab anyone reccommend a specific TV engineer type forum or group
that may be able to help? I'm desperate here folks :)
 
I am working on a Sanyo AVM-2547U Tv , all of the electrolytic caps
check out fine.There is no audio when you power it up. when it runs for
about 10 min. the audio slowly comes back, but it is garbled. their are two
IC's TDA 7132 audio output IC,s I freeze sprayed them but no change. I think
it could be the tuner? there is a 2 watt resistor in the supply right beside
it maybe causing this? any suggestions?

James
 
Trying to give you a definitive answer based solely on the info you
gave is a little like divination, but it sounds like your tube is OK,
and that you otherwise have some problem in a video output section
somewhere.

I'd guess you're going to need a schematic and a scope for this one.
 
You should calculate everything, the shunt resistor too!

I assume the current to the batteries is constant enough to do this.

Ideally, you would have a wire (0 ohms) feeding the current to the
batteries. But you want to tap off just enough current to light the
LED, while sending the rest to the batteries as before. There's
probably a range of values that will work for you.

Measure the (max) current to the batteries first, to see what you're
working with.

Take the voltage drop of the LED, and add just a bit of headroom (for
instance, if the LED drops 1.0V during conduction, use 1.5V.) Then use
Ohm's law to figure out what series resistor you'll need to get the mA
current you need (the LED's rated operating current) through the LED
with 1.5V across the whole thing.

Finally, take the current you measured going to the batteries, and use
Ohm's law again to determine what size shunt resistor you'll need to
get your 1.5V voltage drop. Use Ohm's law again to make sure the shunt
resistor is large enough in terms of wattage.
 
I am working on a JVC M# AV-27770. I have checked all caps HOT verticle
caps, power supply caps. resistors are all measuring OK. The TV rellay
clicks but no start. I have put a few hours into and am really stuck. I am
thinking it might be the tube. Is JVC known for bad tubes the set is only 9
Yrs old.

Thanx James
 
"spudnuty" <spudnuty@lycos.com> wrote in message
news:1142540707.074366.178280@v46g2000cwv.googlegroups.com...
Mr Fixit wrote:
"Mac" <marmac2@mindspring.com> wrote in message
news:WvjSf.4846$sL2.2506@newsread2.news.atl.earthlink.net...
Hi folks,
I have a BenQ 567s V2 LCD monitor that is non-functional. It powers up
but the only picture I get is pure white with vertical red and blue
lines.
While booting, however, I was able to read some of the on-screen text
but
it's always fairly white. I disassembled the unit (observing all
precautions) but didn't find any loose connections.
I had sold the unit in working order but the buyer found it in this
state
after shipping. It was well packed with gobs of bubble-wrap. I had
him
ship it back. There are no signs of abuse inside or out.
Any thoughts?
Thanks,
-Mac
Did you disassemble the display all the way down to inspect the
connections onto the display itself? or the display driver board? I
just worked on a Compaq laptop with LCD problems and the flex cable had
just popped off the display driver board in a number of places. It was
a soldering problem because I tested some of the components on that
same board and stopped because they would just pop off under the
slightest pressure.
Richard
Click to expand...
I stopped just short of removing the panel from it's metal frame. I could
see the back sides of the FFCs, where they attach to the pcb, but not where
they connect to the panel. They looked prestine on the back so I didn't go
any further. Time for more disassembly.
Thanks,
-Mac
 
"Charles Schuler" <charleschuler@comcast.net> wrote in message
news:K6qdnfC2bse7RoTZnZ2dnUVZ_sadnZ2d@comcast.com...
Bill writes good stuff. I'll just add that Comcast is very responsive to
the these issues and you should first try their technical support. Has
always worked for me and at no extra charge.
Click to expand...
By the way, I always request broadband technical support ... maybe that's
the difference.
 
Ok Accept my apologizes I just didn't like the final line.
kip


"Mr. Land" <graftonfot@yahoo.com> wrote in message
news:1142532655.550674.315890@j52g2000cwj.googlegroups.com...
kip!

Read my post again.

Carefully, this time %^)

I was talking about the original poster, not you.
Click to expand...
 
I need to repair tek 2215a.Please i want diagram for tek 2215.
Thankyou!


--
dorel
 
I'm not sure if you get what he's saying, so my apologies for mentioning
it again- is it possible the buyer had an identical bad monitor and
ripped you off by keeping your good one and sending his duff one back?
This unfortunately happens on eBay- people look for someone selling a good
item identical to a faulty item they have, then try to return their own
garbage to the seller and demand a refund.

They might even go as far as to swap out the insides so on the exterior
you're getting the right monitor back with the correct serial number, but
the wrong innards- there's just no way of knowing now.

The only way to deal with this is the note the serial number of any
electrical items you send out, and if possible make the item tamperproof
so you know if they've opened it, ie by getting some labels made up to
stick over the screw holes, or filling one of the screw holes with wax.

It seems very suspicious to me that it worked when it went out, and came
back faulty. I doubt it could have been damaged in transit- the glass is
the most fragile part and that is intact so I have a feeling you've been
'had'.

Dave

Man, I never would have thought of that! I guess my mind just doesn't work
Click to expand...
that way.
Actually though, I did get the same one back. It has a tiny spot on the
screen in the lower right hand corner that looked as if someone had tried to
clean it and was a little too aggresive. It's only noticable when the unit
is off and the light is just right, but it's there. So unless he swapped
the anti-glare...
Well, short of having a donor for swapping parts, this ones a gonner. Oh
well, live and learn.
I do agree though, doesn't seem like a board could go bad in shipping,
unless they stacked it on an operating Tesla Coil!
Thanks for the help,
-Mac
 
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