Toshiba TV29C90 problem; Image fades to black...

[David]

A small 13" degausser probably has a low enough field not to significantly
damage the built in magnetism Sony uses in the metal banding and aperature
grill of the tube.

Now if you had used one of the old larger 25 inch super strong jobs, good
chance of doing damage. You got the right one.

You will need to go completely around the set several times with the smaller
degausser and slowly move it away. The internal degauss would take a few
days for it to go away, but not with an external coil.

That size tube, anything within feet of the set with magnetic capable metal
on it can and will affect purity, as will the orientation of the earths
magnetic field. Since it is in the corner, I would bet that the tilt/earth
magnetic field correction might help the problem at a different setting.

If none of those things work even after moving all electronic equipment away
from the set, call in a Sony trained rep and make sure they contact Sony or
recently went to training for the PROPER Sony way to adjust the
purity/convergence/etc on that set.

<shokus@yahoo.com> wrote in message
news:a0b03522.0307301532.470d7157@posting.google.com...

I just bought a Sony 40XBR800 set. There are those that say
degaussing it manually with a coil is OK, and then there are those
like David who say to never use an older, big coil. I had my center
speaker for my sound system (it has since been moved) on top of the TV
and noticed I was getting a very slight yellowish color in the bottom
lower left of the screen that only appears when there is white in that
corner to show it. When other colors appear, it is not noticeable. I
went out to a local electronics store and bought a brand new degausser
(13" inches in diameter) and tried to fix the problem. It did go away
when I placed the degausser near it and began rotating away in a
circular motion, but as I moved away, the yellow came back again, and
the picture is as it was before the degaussing. Nothing seems to have
been damaged as a result of using this degausser but the problem still
remains. I have nothing near the set now except my 4DTV satellite
receiver on one of the shelves of the stand that came with it, and an
HD OTA receiver on the lower shelf. I have two questions - first, did
I do any damage to the set at all using this new degausser? If I did,
nothing is noticeable. Is there a way to check? Second, I'm told
when the object that possibly caused the magnetism is moved away, it
can take a few days for the set to automatically degauss itself and
clear up the problem - is that correct? Any help will be greatly
appreciated. Thanks!

Sincerely,

Stuart

 

[LASERandDVDfan]

Does anyone agree with this or could it something else. Unfortunately
my manual says the schematics would be provided in the next update
which I don't have.

The only advice I can offer is to take apart and clean the affected parts. Use
a good aerosol circuit cleaner spray as there could be mineral deposits from
the flood water that can cause problems. You may also want to look around for
cold solder joints. You may also want to consider replacing the old coolant
and, if required, cleaning out the lens assemblies according to the
television's service literature, even if you don't see any problems. -
Reinhart

 

[Jason D.]

On Wed, 30 Jul 2003 13:11:45 -0600, "woodward_electric"
<woodward_electric@hotmail.com> wrote:

vertical caps, vertical ic, diode in vertical circuit esr the caps and some
basic trouble shooting will solve the problem

"charlton shirley" <cshirle1@worldnet.att.net> wrote in message
news:BtDVa.76170$3o3.5214735@bgtnsc05-news.ops.worldnet.att.net...
I have a rca ctc168fc with a vertical problem. Only a half inch horizontal
line across screen. High voltage and sound ok. Any help would be greatly
appreciated.
C. Shirley
cshirle1@worldnet.att.net

That chassis is unusual for vertical circuit, doesn't use DC coupled
linear amp design that's used often with early ones using two
transistors vertical or more common ones using IC.

CTC168/CTC169 shares same basic design and how vertical pulses is
produced before going into main ampifier section is same. BUT
vertical is done with a SCR transistor amptitude chopping horizontal
pulses directly from secondary winding on flyback itself into what
looks like vertical waveforms. Vertical retrace simply had SCR full
on for few horizontal pulses. Really nifty & efficient but can be
confusing to people who have seen it for first time.

You have problem with vertical front end (power) or faulty component
that is too lossy in that circuit that is part of vertical winding or
the vertical generator using an 8 pin LMxxx IC is putting out weak
signal or distorted signals. Jungle IC only outputs narrow
vertical-rate pulses, this small IC turns it into sawtooth with
retrace, other half of same IC intergrates the horizontal rate with it
to get correct trigger timing for that SCR. Check solder real
carefully too. Scope is a must to find fault that causes power loss.

It has vertical size pot, check that circuit is working.

Cheers,

Wizard

 

[Bill Jr]

Tom,
Your diagnosis seems to be correct.
Just an added tidbit, if the coolant chambers for the CRT's are clear and
free of any algae then leave them alone.
I'll try to look up the part number for the G2/Focus block when I get to
work tomorrow.
It would be really helpful to have the model number as they used a variety
of different CRT's with different models and they require different levels
of focus/G2.

Good Luck,
Bill Jr




"Tom" <tom.rae@comcast.net> wrote in message
news:8f4c2129.0307301437.53faa27a@posting.google.com...

Someone we know had a flood and their Magnavox PTV500 Series was in
it. Covered by insurance they received a new one and I took the old
before the garbage man got it. The tv was off but plugged in, so
everthing powered by the standby voltage cooked and fell off the
board. I bought the repair manual from Philips for $30 and $50 worth
of parts that were obviously damaged. I replaced them but didn't have
it working yet and it sat for about 6 years. I finally got back to it
and found the final 1/4watt 15 ohm resistor that was open circuited.
This is the resistor that feeds the standby circuit of the power
supply. Turned it on and YES it worked great. No fluid bacteria that I
read about on the newsgroup which is suprising because it spent its 6
years in a damp basement. So the TV works great until summer comes
and the basement gets humid. The focus goes out and then clears after
the TV warms up. It slowly gets worse. Now when you turn it on only
the blue gun comes on and it flickers when one of the high voltage
cables going into the High Voltage distribution block shows some
arcing. As it warms the arcing stops and the green gun will come on
and then after much time the red. After a day of being on it looks
good but no perfect. I can point a small space heater at the boards
and within an hour the TV look like new with a great in focus full
color picture. Now the flood water came up about half way on all the
boards. About a foot high. This would put the high voltage
distribution block under water and there was dirt left on the boards.
I am thinking that the high voltage distribution block is the cause.
This is where the RGB focus and convergence pots are. Turning the
heater off causes the picture to get fuzzy but the color holds.
Turning the tv off for a short while causes it to go back to just blue
and then slowy comes back unless I leave the heater on.

Does anyone agree with this or could it something else. Unfortunately
my manual says the schematics would be provided in the next update
which I don't have.

Thanks for your opinions!
Tom

 

[Jon Scott]

Thanks to all who responded! In the absence of dissenting opinions, I humbly
accept the wisdom of my learned colleagues, and acknowledge that of my g.f.

Jon

Asimov wrote:

"Jon Scott" wrote to "All" (22 Jul 03 03:42:44)
--- on the topic of "Two amps, one speaker pair"

Your g.f. (god father?) is right. You are lucky to have a smart g.f.
to keep you from burning down the house. <g

JS> From: Jon Scott <prestwich@NSPearthlink.net
JS> Reply-To: prestwich@NSPearthlink.net

JS> So my g.f. wants to use the same pair of speakers for two different
JS> amps -- one music and one video source. She thinks she needs a selector
JS> switch; I think she can wire the speakers to both amps simultaneously
JS> without hurting the receivers or the speakers.
[,,,]
JS> Comments? I know there are other wiring options, and I know what they
JS> are, I'm just wondering whether this one could be deleterious.

... A couple of volts below threshold.

 

[Andre]

tom.rae@comcast.net (Tom) wrote in message news:<8f4c2129.0307301650.4657062b@posting.google.com>...

Andre,

There are current regulator diodes.
http://www.vishay.com/docs/70711/70711.pdf
and there are others. These range from .43 ma to 4.7 ma. May not be
enough to keep your fan going, but you could put a few in parallel to
adjust.

Interestingly, you cannot parallel LM317x regulators to get more
current . Even if you use diodes to separate them it will not work .
2*100mA regulators give about 143 mA or so .

Any ideas why ?

-A

Tom

 

[Ed Ellers]

Scott McDonnell <NetSamurai@[delete]comcast.net> wrote:

"The model is RD8518AK04, it says it is made by Magnavox, but the only
reference I have found to it online is to a Sylvania with the same model
number."

Philips used to have a lot of identical sets under the Magnavox and Sylvania
brands -- Magnavox for mass merchandisers and Sylvania for independent local
dealers.

 

[Dan]

Here is what I found at repairfaq.org for those with the same problem:

Identifying connections on unknown or cut monitor cables:

Obviously, this is best done with a schematic. However, since such a
luxury may not be possible, how can you go about figuring out where
all the wires go? Easy answer - very carefully.
For the following, I assume a VGA/SVGA monitor. You need to identify
the grounds, video signals, H and V sync, and monitor sense lines. The
procedure is described with respec to a cut cable but if you are
trying to identify an unknown connector type on the monitor, the same
comments apply to the wiring **inside** the monitor.

First identify the grounds. Use an ohmmeter between each wire and the
shell of the video connector on the monitor. Resistance will be less
than an ohm for the ground wires. These will often be colored black.
The shields of the RGB coaxes will also be connected to ground.

The high bandwidth video signals will always use individual coaxial
cables. These may even be color coded red, green, and blue. If not,
you can determine which is which later on. If there are only three
such coaxes, they are the video signals. If there are four, the extra
one may be the H sync. If there are five, the extra two may be the H
and V syncs. Testing between these wires and ground with an ohmmeter
should measure 75 ohms for the video terminations.

Display a lively screen on your PC at a resolution you know the
monitor should support (remember, trying to drive a monitor of unknown
scan rate specifications beyond its ratings is like playing Russian
Roulette.) When in doubt, VGA (640x480, 31.4 kHz H, 60 Hz V) should be
safe.

Turn up the brightness and contrast on the monitor. If you are lucky,
even without any sync, there will be a visible raster. Set it to be
just visible. If there is none, then it should appear once there is
valid sync.

You will need to bring out wires from the video connector on your PC.

Connect the ground of your video card to the ground wires you already
identified on the monitor cable.

Attach a wire in series with a 200-500 ohm resistor to H sync (pin 13)
on the VGA connector.

Momentarily touch the end of this wire to each of the remaining
unidentified wires (including the coaxes if you have 4 or 5 of these
and it is not obvious which are the video signals) on the monitor.
When you find the H sync input, the raster should lock in and probably
brighten up. If the monitor was originally whining due to lack of
sync, it should quiet down.

Once you have located H sync, you can remove the resistor and connect
the wire up directly.

Now, attach the video signals. It is likely that you will now have a
picture but it will be rolling on the screen. Some monitors, however,
will not unblank until they receive both valid H and V sync. Use your
resistor with the V sync output of the video card (Pin 14) on the
remaining unidentified wires. Once you find the V sync input, the
display should lock in solid.

The only remaining unknowns are the monitor sense lines. For older
monitors - those without the ACCESS.bus interface, you can just wire
up the sense lines to the appropriate levels (Color: ID0 (Pin 11) to
ground, ID1 (Pin 12) NC).

See the document "Pinouts for various connectors in Real Life(tm)" for
detailed hookup information". Replacement VGA connectors are readily
available.



..

There's a writeup somewhere on repairfaq.org about this.

Black Red Yellow White Orange
and then there 3 additional wires wrapped in shielding that are Blue
Red and Green (RGB)

...
i am assuming red is hot, and black is ground

Not in this case.

There are only 8 wires, but according to the pinout for
standard pc monitor, there should be 13.

Each of the 3 coaxial wires occupies 2 pins (one for the conductor and one
for the shield). Anyway, only 10 of the pins are important.

-- uns

 

[Lionel Sharp]

Michael A. Terrell wrote:

Lionel Sharp wrote:

Will make it an expensive repair with the company having an $1000
minimum order policy.

Current Terms and Conditions...

Minimum Order..... $1000 (orders less than $3000 are scheduled for
single release)
Shipping.................. F.O.B. - Tempe, AZ
Packaging............... Standard packaging will be used unless
otherwise specified.

Lionel L Sharp
VK4NS

Michael A. Terrell wrote:

"G. Skiffington" wrote:


Looking for 4 units (or 2 minimum) of this 18 pin dip. Used in the
Yaesu FT767GX, Heathkit HW5400 and likely other equipment - not having
any luck, so far, trying to find a supplier in Canada or the US with
stock. Any leads or help appreciated (I have data).

remove REDUCE to reply



Obsolete, and the rights to manufacture were sold to Lansdale
http://www.lansdale.com/prdmot10.htm


You might get them to tell you who bought a quantity, and buy a
couple from them. I know that Lansdale is hard to deal with. They make
their money on E.O.L. parts to complete contracts. At least SOMEONE is
making replacement parts.

Just as a matter of interest I checked with Dick Smith Electronics who
were the FORMER distributors for YAESU. DSE spare parts department reply
is as follows:-

Thanks for your e-mail dated 31//7/03. Unfortunately the
G 1090550 MC145145P was discontinued by Yaesu back
On the 1/06/02 and therefore is no-longer available.

Another company worth trying is lowe Electronics @

http://www.lowe-electronics.com

Or Comptrade @

http://www.comptrade.com/

Lionel L Sharp, VK4NS

 

[woodward_electric]

run stby
pin 1 -40.1 -27.8
pin 2 -33.3 -22.7
pin 3 hgnd
pin 4 -1.54 2.01
pin 5 1.32
pin 6 1.45 1.31
pin 7 -.43
pin 8 0.12
pin 9 0.12
pin 10 nc
pin 11 156.5 169.2
pin 12 156.5 169.2

"Sidney" <sidneybek@yahoo.com> wrote in message
news:fecdbb87.0307301818.6f318616@posting.google.com...

25" GE stereo TV model:25GT539,chassis:CTC187AB,year:Oct 97,no
power,the power supply does not chirp,pins 11 & 12 of
U4101V=STK730-130 have an output,I would like to know the proper
standby voltages for U4101V=STK730-130.
I checked R4104=1.5 M ohms,1/4 watt supplies start up voltage to
U4101V but it was fine,I checked the Q4401=2SD1878 and of course
T4301I=horizontal driver transformer for cracked solder.
I resoldered tuner which had many cracked grounds,I also checked th
EEPROM for activity like VCC,clock and data but all were missing
because I assume that the problem lies with a defective
U4101V=STK730-130,I need the standby voltages for it.
Thanks in advance.

 

[Frank de Lange]

google-f@unternet.org (Frank de Lange) wrote in message news:<93f382d9.0307290927.16636f1e@posting.google.com>...

This monitor came out of powersave mode, I heard and saw a spark
somewhere inside (sparkgap?), and the picture cam up washed out and
way too bright. Retrace lines were visible, picture got bigger/more
washed out, turned unit off.

I found the problem:

On the CRT board, top right, solder side, in the +195V (measured, I do
not know the design voltage as I do not have a schematic
diagram/service manual) supply line, a (surface-mounted) diode had
turned into a useless o/c glass tube. This was caused by sparkover on
the component side between the supply line and ground (caused by???
dirt? bugs?).

(This does not seem like a normal failure mode for this monitor...)

Replaced the diode with something which measured more or less
identical on my DMM (there's no ID on those SM diodes, and I do not
have a schematic diagram...), turned it on, it works.

Cheers//Frank

 

[Dave D]

"Andre" <testing_h@yahoo.com> wrote in message
news:2c2cf14c.0307310003.4cf2199d@posting.google.com...

tom.rae@comcast.net (Tom) wrote in message
news:<8f4c2129.0307301650.4657062b@posting.google.com>...
Andre,

There are current regulator diodes.
http://www.vishay.com/docs/70711/70711.pdf
and there are others. These range from .43 ma to 4.7 ma. May not be
enough to keep your fan going, but you could put a few in parallel to
adjust.

Interestingly, you cannot parallel LM317x regulators to get more
current .

Try using the LM317 to drive a pass transistor capable of passing the
required current. Mind, the LM317 is more than capable of supplying the
200mA you say your fan requires!

Dave

 

[Mike]

I wouldnt run it anymore, untill you get that block replaced. Cause, if you
let it go, the block will eventually short, taking out the HOT, possibly
flyback. and youll have a whole mess of trouble.








"Bill Jr" <bill@nospam.usa2net.net> wrote in message
news:Ft1Wa.3463$qg3.209659@twister.tampabay.rr.com...

Tom,
Your diagnosis seems to be correct.
Just an added tidbit, if the coolant chambers for the CRT's are clear and
free of any algae then leave them alone.
I'll try to look up the part number for the G2/Focus block when I get to
work tomorrow.
It would be really helpful to have the model number as they used a variety
of different CRT's with different models and they require different levels
of focus/G2.

Good Luck,
Bill Jr




"Tom" <tom.rae@comcast.net> wrote in message
news:8f4c2129.0307301437.53faa27a@posting.google.com...
Someone we know had a flood and their Magnavox PTV500 Series was in
it. Covered by insurance they received a new one and I took the old
before the garbage man got it. The tv was off but plugged in, so
everthing powered by the standby voltage cooked and fell off the
board. I bought the repair manual from Philips for $30 and $50 worth
of parts that were obviously damaged. I replaced them but didn't have
it working yet and it sat for about 6 years. I finally got back to it
and found the final 1/4watt 15 ohm resistor that was open circuited.
This is the resistor that feeds the standby circuit of the power
supply. Turned it on and YES it worked great. No fluid bacteria that I
read about on the newsgroup which is suprising because it spent its 6
years in a damp basement. So the TV works great until summer comes
and the basement gets humid. The focus goes out and then clears after
the TV warms up. It slowly gets worse. Now when you turn it on only
the blue gun comes on and it flickers when one of the high voltage
cables going into the High Voltage distribution block shows some
arcing. As it warms the arcing stops and the green gun will come on
and then after much time the red. After a day of being on it looks
good but no perfect. I can point a small space heater at the boards
and within an hour the TV look like new with a great in focus full
color picture. Now the flood water came up about half way on all the
boards. About a foot high. This would put the high voltage
distribution block under water and there was dirt left on the boards.
I am thinking that the high voltage distribution block is the cause.
This is where the RGB focus and convergence pots are. Turning the
heater off causes the picture to get fuzzy but the color holds.
Turning the tv off for a short while causes it to go back to just blue
and then slowy comes back unless I leave the heater on.

Does anyone agree with this or could it something else. Unfortunately
my manual says the schematics would be provided in the next update
which I don't have.

Thanks for your opinions!
Tom

 

Thanks for the FAST reply, David. It's a relief to know the degausser
did not damage the set. This morning the problem still remains. On a
picture with just snow, the yellow splotch is very prominent in the
lower left corner, as is a very slight blue splotch in the top left,
and another yellowish splotch appears near the upper right corner,
too. When the tube is showing actual video, nothing compromises the
picture except the bottom left yellow splotch that I originally wrote
about. I went around the picture tube twice with the degausser;
obviously that was not enough. How many times do I need to go around,
and how far away from the set should I be when I start? I noticed
when I was about 1.5 feet away, it greatly affected the entire tube.
I don't want to get too close. Maybe I should just wait two more days
and see if the internal degausser fixes it? BTW, using the tilt
correction, which only has a + / - ratio of 7, did not help. Also,
that center speaker is now about 4 feet away from the set, up on top
of a wooden entertainment cabinet. That should be far enough away I
hope. Thanks again for the help!

 

[jakdedert]

Disconnect *everything* except for CPU & video! . If it won't POST with
just CPU, mb, video and ps; something must be wrong with one of them.
Substitute each until you get POST.

If it does POST, keep reconnecting things--starting with RAM--until it
doesn't...BINGO!

jak

"Gary Tait" <taitg@hurontel.on.ca> wrote in message
news:ticthvsr2i4oni1268nmung38sbre9rfvs@4ax.com...

On Wed, 23 Jul 2003 13:48:56 GMT, techno2nospam@videotron.ca (Doug
Taylor) wrote:


Well here goes a run down of a typical PC repair experience
for me....

A friend gives me his old PC Pentium 100 Mhz as it's not working.
As a challenge I decide to dig into to see whats wrong.

First, I set it up on the bench, remove the modem and sound card
and restart it with only video card to see if It will boot.. Blank
screen.
Then I sub out the video card and reboot... Blank screen.
Could be power supply, although seems to be getting power O.K.
to drives etc, check power plug motherboard with meter...O.K.
Sub out power supply anyways to be sure. ...blank screen.
Hummmmm whats next....
Sub out memory and re-seat.... no go.
Reseat CPU ..... nope............
Check out motherboard to make sure it is not shorted to bottom metal
plate.(happened once before on another system)
What's next.... motherboard or CPU....
Go out and buy used Pentium 125Mhz motherboard with CPU.
Sub CPU.... no go ....
Sub motherboard & CPU ....BINGO ... we got a winner......

Have to cut bigger hole in case for PS2 mouse & keyboard of new
motherboard as old motherboard had COM port mouse and DIN keyboard plug.

Plan to put Linux on this system and use as a learning tool.

Question: Do you people have some constructive input into
the method I used to troubleshoot this system?

I'm kinda old(54) dyslexic & semi-retarded with bad eyesight,
but besides that I'm not a total idiot. 8*)

My conclusion is that the BIOS Rom failed.
What do you think?

Doug

Try disconnecting drives. Try a known working video card, or
that video card in a known working system. Same with other components.

 

[Luke]

Yeah it is caused by interference between the pixel grid of the image and
the dot pitch of the monitor.

It's probably more likely to happen when you are running a buget monitor at
a high resolution because cheaper monitors do not have such a fine dot
pitch.

So try changing the resolution or even just changing the size of the image
using the monitors geometry controls.

Also try cleaning your screen, sounds silly but fine streaky marks, residue
from careless cleaning or fine scratches can cause the same effect, so just
check that is not the cause.

Luke


"Rick Wilson" <nospam@earthlink.net> wrote in message
news:atqfon$1ph2b$1@ID-82690.news.dfncis.de...

"Michael P. Broida" <michael.p.broida@boeing.com> wrote in message
news:3E00BBF8.6CA427B6@boeing.com...
Anna wrote:

hi,
whenever i bend forward (rather quickly) towards the monitor or lean
back and i'm looking at a fixed point on a white (or otherwise bright
colour) background, i see vague white diagonal lines sort of crossing
eachother and converging at the spot i'm looking at. they disappear
when i stop moving my head. is this common for all monitors or is it
this brand (samtron) or is any setting wrong? it can get annoying if i
move forward or backwards in my chair when i'm reading text against a
white background or working on images that have a lot of white.
refresh rate is 85 hz but even setting it to 100 doesnt seem to help
much.

Sounds like a Moire pattern. Some monitors have
adjustments that are supposed to reduce that, but
I've never seen it help. Some people don't even
notice them anyway. Do you wear glasses? Strong
corrective lenses can make it more obvious, I think.

Try turning down the brightness/contrast a bit.

Biggest help: clean the glass on your monitor.
Spots on the monitor make it easier to see those
patterns. And clean your glasses as well.

Also try a different resolution on the monitor.

RickW

 

[Rep]

Message like the one you have below implies that you have way too much
lead in your system! You forgot to include wear a mask, do your
soldering on a ventilated system and wash your hands after.

"Mark D. Zacharias" <mzacharias@nospam.earthlink.net> wrote in message news:<h__Va.126365$Io.10746851@newsread2.prod.itd.earthlink.net>...

OK, I've been waiting to post this. Here it goes:

First, learn some electronic theory and fundamentals, so that you will not
injure or kill yourself, and so you will know a bad part when you find one.
It is critically important to understand theory of operation and signal-flow
if you are to have any hope of repairing most equipment.
Buy a relatively inexpensive digital multimeter, probably at Radio Shack.
An oscilloscope would also be most useful; a decent used one can usually be
found for 100.00 or less.
Learn the appropriate safety considerations for using the tester and 'scope.
There are special considerations for working on most televisions and other
equipment not using a built-in isolation transformer. Most servicers use an
isolation transformer for any AC-powered unit under test.
Learn how to use the multimeter to measure resistance, voltage, and current.
Learn how to use the oscilloscope to observe and analyze waveforms.
Buy a soldering iron, solder, and desoldering equipment.
Learn how to solder and unsolder without damaging the circuit board.
Find a source for replacement parts. Most suppliers have about a 15.00
minimum order.
Order the replacement parts and install them.
Clean the circuit board where you were soldering. Treat the job as if it
were going to be inspected afterwards and graded for neatness.
Visually inspect the piece for any other problems or safety issues.

NOTE:
You are personally responsible for any safety problems you cause, or those
which you
SHOULD have noticed and failed to correct. So if you work on a TV and it
burns down your friend's house in the middle of the night because
of something you missed or that you caused, they can sue you, even years
later.
At this point you can just replace a blown fuse, if any, plug the unit in,
and hope your new parts don't just fail again because you missed something
or installed a part incorrectly. (Or you could use an AC variac to bring up
the line voltage slowly while measuring voltages etc. MCM sells one for
90.00)

Check for normal operation. Watch for any signs of overheating, hum, smoke,
etc and be prepared to shut down quickly.
Test for longer-term operational stability, check for neatness of lead
dress, re-assemble the rest of the way, making sure not to pinch any wires
etc. Make up your mind to re-assemble the piece exactly as it was. If there'
s screws left over, you did a sloppy job.
Final test the piece, and satisfy yourself that there is no possibility of
leakage current between any exposed metal and the AC line. There are several
ways of doing this. Please refer to the manufacturers' service data or your
textbooks.

Decide how to politely tell friends, family, freeloaders and cheapskates
that you must charge appropriately for your work.

Welcome to the exciting world of electronics repair.

Mark Z.



"Sofie" <sofie@olypen.com> wrote in message
news:vifo44ljlkra66@corp.supernews.com...
George:
Based on your original posting, a manual and a schematic are NOT going to
be
much help to you...... it will only be of most use to an experienced and
knowledgeable tech with the proper test equipment, tools, replacement
parts,
etc. In fact, most techs will repair this kind of problem without the
manual and schematic.
The Sansui 9090 is a very nice old and powerful receiver and is worth
repairing. Take it to a repair shop BEFORE any failed, botched or
aborted
home repair attempts and at the very least get a repair cost estimate so
you
can make an INTELLIGENT repair decision with facts instead of internet
guesses.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
-----------------------------------


Today I turned on the Sansui 9090 and the flashing red protector
light
next to
the power button continuously flashed and the stereo never did go on.
The tuner
seemed to be picking up signals, as evidenced by the signal meter,
but
the
sound output meters registered zero and no sound came from the
speakers.
Usually
the light flashes red for a few seconds, turns green and then the
tuner
and
stereo activates. Can someone tell me what the cause might be and if
there is a
simple fix> > I don't have a manual for the unit, and have no idea
what
the protector light is
for. Can someone tell me where to obtain a manual?
Thanks.
George

 

[Bob Myers]

"Luke" <luke_a_p@hotmail.com> wrote in message
news:bgbp72$hq8$1@sparta.btinternet.com...

Yeah it is caused by interference between the pixel grid of the image and
the dot pitch of the monitor.

No, I'm afraid not. What everyone is missing so far is the
following from the original:

hi,
whenever i bend forward (rather quickly) towards the monitor or lean
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
back and i'm looking at a fixed point on a white (or otherwise
bright
colour) background, i see vague white diagonal lines sort of
crossing
eachother and converging at the spot i'm looking at. they disappear
when i stop moving my head.

Moire is NOT going to be affected by the motion of the
observer.

What's happening is simply the fact that if someone moves
quickly enough, such that a CRT monitor screen passes rapidly
through the field of view (and especially if this were going on in a
darkened environment, such that the monitor is the brightest object
in the field), you can see all sorts of such artifacts caused by the
normal raster-scan action of the display. It is perfectly normal,
and nothing to be concerned about.

Bob M.

 

[Peter]

I reckon you're right about the bios chip having failed. Did you try
removing the bios chip and carefully reseating it?
In future when this happens get a replacement bios chip from
www.badflash.com

Peter
"jakdedert" <jdedert@bellsouth.net> wrote in message
news:0jfWa.8632$f%2.2068@fe05.atl2.webusenet.com...

Disconnect *everything* except for CPU & video! . If it won't POST with
just CPU, mb, video and ps; something must be wrong with one of them.
Substitute each until you get POST.

If it does POST, keep reconnecting things--starting with RAM--until it
doesn't...BINGO!

jak

"Gary Tait" <taitg@hurontel.on.ca> wrote in message
news:ticthvsr2i4oni1268nmung38sbre9rfvs@4ax.com...
On Wed, 23 Jul 2003 13:48:56 GMT, techno2nospam@videotron.ca (Doug
Taylor) wrote:


Well here goes a run down of a typical PC repair experience
for me....

A friend gives me his old PC Pentium 100 Mhz as it's not working.
As a challenge I decide to dig into to see whats wrong.

First, I set it up on the bench, remove the modem and sound card
and restart it with only video card to see if It will boot.. Blank
screen.
Then I sub out the video card and reboot... Blank screen.
Could be power supply, although seems to be getting power O.K.
to drives etc, check power plug motherboard with meter...O.K.
Sub out power supply anyways to be sure. ...blank screen.
Hummmmm whats next....
Sub out memory and re-seat.... no go.
Reseat CPU ..... nope............
Check out motherboard to make sure it is not shorted to bottom metal
plate.(happened once before on another system)
What's next.... motherboard or CPU....
Go out and buy used Pentium 125Mhz motherboard with CPU.
Sub CPU.... no go ....
Sub motherboard & CPU ....BINGO ... we got a winner......

Have to cut bigger hole in case for PS2 mouse & keyboard of new
motherboard as old motherboard had COM port mouse and DIN keyboard
plug.

Plan to put Linux on this system and use as a learning tool.

Question: Do you people have some constructive input into
the method I used to troubleshoot this system?

I'm kinda old(54) dyslexic & semi-retarded with bad eyesight,
but besides that I'm not a total idiot. 8*)

My conclusion is that the BIOS Rom failed.
What do you think?

Doug

Try disconnecting drives. Try a known working video card, or
that video card in a known working system. Same with other components.

 

[Lionel Sharp]

Clifton T. Sharp Jr. wrote:

Lionel Sharp wrote:

Just as a matter of interest I checked with Dick Smith Electronics who
were the FORMER distributors for YAESU. DSE spare parts department reply
is as follows:-

Thanks for your e-mail dated 31//7/03. Unfortunately the
G 1090550 MC145145P was discontinued by Yaesu back
On the 1/06/02 and therefore is no-longer available.


I see it still appears that no one bothered to plug "MC145145P" into
Google.

Yes I did Clinton. That is where the comtrade reference came from in my
earlier email. Copy of relevant section from 31/7/03 follows:-

Thanks for your e-mail dated 31//7/03. Unfortunately the
G 1090550 MC145145P was discontinued by Yaesu back
On the 1/06/02 and therefore is no-longer available.

Another company worth trying is lowe Electronics @

http://www.lowe-electronics.com

Or Comptrade @

http://www.comptrade.com/

Lionel L Sharp, VK4NS