I have an AppleVision 850AV monitor, which uses a 20" Sony Trinitron tube.
It was made in late 1997. Over the last year it has developed a multitude of
problems effectively making it unusable.

1. Image has lost focus.

2. Many resolutions and/or refresh rates (but not all) have developed a
proportion problem. The image at the sides is very squashed whereas it is
spread out at the centre. Some resolutions and/or refresh rates have ceased
to work altogether, even if they are not out of range - screen goes blank
and makes a weird noise.

3. Most annoyingly - the whole picture ripples all the time. The pixels
basically jitter, and the monitor emits a buzzing sound. This occured
recently and very suddenly, on all resolutions.

I have taken the screen apart and looked at the Analog board. I found a
charred bit and resoldered a couple of burnt contacts. Put it all back
together but no improvement. 1 should be an easy fix, but what about 2 and
3? I have no idea where to begin.

TIA.

1. Loss of focus is usually attributed to high voltage regulation and focus
supply regulation faults. This can be from the HV multiplier to start with.

2. This sounds like you have a combination of pin cushioning and vertical
deflection problems. This is usually attributed to warn down capacitors in
these areas, and also possibly other support components.


3. Jitter can be from a stability problem. This can be from supply voltage
regulation, or noise in the supply voltage. This is usually attributed to
capacitors that may be wearing down, or other support components.

Unless you can have the service manual, training, troubleshooting skills,
and instrumentation, you will not be able to service this yourself. This
monitor also has multiple problems.

If this is an expensive model (No model number and manufacture name given.
Many use the Trinitron tube.), I would suggest you find out who their
authorized service centre is, and send them the monitor for an estimate, so
you may be able to make an intelligent decision about servicing it.

There are very serious safety issues when servicing monitors, and TV sets.
There are some very high voltages employed, and the power supply used can be
lethal. Strong safety precautions and procedures are in good order when
working in these.

--

Jerry G.
=====


"Peter Baran" wrote in message
...
I have an AppleVision 850AV monitor, which uses a 20" Sony Trinitron tube.
It was made in late 1997. Over the last year it has developed a multitude of
problems effectively making it unusable.

1. Image has lost focus.

2. Many resolutions and/or refresh rates (but not all) have developed a
proportion problem. The image at the sides is very squashed whereas it is
spread out at the centre. Some resolutions and/or refresh rates have ceased
to work altogether, even if they are not out of range - screen goes blank
and makes a weird noise.

3. Most annoyingly - the whole picture ripples all the time. The pixels
basically jitter, and the monitor emits a buzzing sound. This occured
recently and very suddenly, on all resolutions.

I have taken the screen apart and looked at the Analog board. I found a
charred bit and resoldered a couple of burnt contacts. Put it all back
together but no improvement. 1 should be an easy fix, but what about 2 and
3? I have no idea where to begin.

TIA.

"Peter Baran" wrote in message
...
I have an AppleVision 850AV monitor, which uses a 20" Sony Trinitron tube.
It was made in late 1997. Over the last year it has developed a multitude
of
problems effectively making it unusable.

1. Image has lost focus.

2. Many resolutions and/or refresh rates (but not all) have developed a
proportion problem. The image at the sides is very squashed whereas it is
spread out at the centre. Some resolutions and/or refresh rates have
ceased
to work altogether, even if they are not out of range - screen goes blank
and makes a weird noise.

3. Most annoyingly - the whole picture ripples all the time. The pixels
basically jitter, and the monitor emits a buzzing sound. This occured
recently and very suddenly, on all resolutions.

I have taken the screen apart and looked at the Analog board. I found a
charred bit and resoldered a couple of burnt contacts. Put it all back
together but no improvement. 1 should be an easy fix, but what about 2 and
3? I have no idea where to begin.

TIA.


I don't think you should even bothertrying a repair. It sounds exactly like
my Apple 17" that I tossed last month. Trinitrons just never seem to repair
right. Just get a new monitor on ebay. I bought 3 (yes, three) 17"
Viewsonics for about $100 including shipping.

I just looked and there's a 17" applevision 17AV, for $10, plus shipping. A
bit smaller, but you won't need a monitor adapter nor have to buy an
outboard sound system.

Once you get something like that then keep your eyes open for a nice cheap
19" monitor with speakers. Buy a monitor adapter anyway so you can use any
monitor on your Mac.

"Jerry G." wrote in message
...
1. Loss of focus is usually attributed to high voltage regulation and
focus
supply regulation faults. This can be from the HV multiplier to start
with.

2. This sounds like you have a combination of pin cushioning and vertical
deflection problems. This is usually attributed to warn down capacitors in
these areas, and also possibly other support components.

3. Jitter can be from a stability problem. This can be from supply voltage
regulation, or noise in the supply voltage. This is usually attributed to
capacitors that may be wearing down, or other support components.

How can I tell which capacitors are wearing down? They all look normal (no
bulging or leaking), can I use something like a multimeter?

Already swapped it out with a 17" Sony 200ES, for the time being; found it
on a dustbin in good condition a while ago. It's hooked up to a G4 which has
VGA video anyway.

Peter