IBM G74 17" monitorProblem with Horizontal width max out

[Aslaner]

I have redone all of the cold joint, found a few bad caps.
I found a 3.3 uf non polarized reading about 35 on the ESR which isn't that
bad but still too high.
I don't have another to replace it with, and have my doubts as being the
problem.

The problem is that the Horizontal width is completely max out. The
adjustment barely make any difference.

I have looked at all transistors aroung the Horizontal cct but none really
read bad. Resistors all check out OK.
There has to be a component causing this but where wuithout a diagram it is
difficult.

Has anyone seen this problem before.

Model 6547-OAN

Any help appreciated

 

[Tom MacIntyre]

I have redone all of the cold joint, found a few bad caps.
I found a 3.3 uf non polarized reading about 35 on the ESR which isn't that
bad but still too high.
I don't have another to replace it with, and have my doubts as being the
problem.

In some circuits that value could be critical. Also, you can
temporarily create your own non-polarized electrolytic using 2
polarized electrolytics, back-to-back. There may be more to it,
though, and someone else may elaborate.

The problem is that the Horizontal width is completely max out. The
adjustment barely make any difference.

I am assuming that this is digital. It may be more than just a simple
analog problem, then.

Tom

 

[Jerry G.]

To replace a non-polar cap at 3.3 uF you can use two of 5.6 uF back to
back. Put the two neg's of the caps together, leaving two positive leads
to connect. This will work, but it is better to get the proper cap.
These caps have a 10 to 20% tolerance, therefore this value will be
close enough.

Some of the component values in these monitors are critical, and you
will not know if the cap is the problem or not, unless you try it, or
you are able to work it out from the circuit design.

--

Jerry G.
======

I have redone all of the cold joint, found a few bad caps.
I found a 3.3 uf non polarized reading about 35 on the ESR which isn't
that
bad but still too high.
I don't have another to replace it with, and have my doubts as being the
problem.

The problem is that the Horizontal width is completely max out. The
adjustment barely make any difference.

I have looked at all transistors aroung the Horizontal cct but none
really
read bad. Resistors all check out OK.
There has to be a component causing this but where wuithout a diagram it
is
difficult.

Has anyone seen this problem before.

Model 6547-OAN

Any help appreciated

 

[Aslaner]

That is what I am afraid, maybe the problem is with the factory set digital
values inside the eeprom, sometimes the data gets corrupted? I know those
Mag Innovation Monitor are notorious for that and some of the ACERs as
well.

 

[Aslaner]

I'll try that and let you know

 

[Aslaner]

Yep
That was the problem
I'll look for one of those caps tomorrow
3.3uf non polarized (bi-polar, I think is the right term for it) 65Vdc


So all of you out there with the same problem, start looking for a cap.

 

[Tom MacIntyre]

Yep
That was the problem
I'll look for one of those caps tomorrow
3.3uf non polarized (bi-polar, I think is the right term for it) 65Vdc


So all of you out there with the same problem, start looking for a cap.

It's always great to hear that we've helped someone.

Tom