Precision sockets are very OK.
I think deleted_01_21 meant the original ones which quality was a common sore.
I feel relieved now...
The bad thing is that you need to understand the schematics and the chips data sheets to check every important component complex.
There are probably good books on this.
Optimum would be if you can find the service manual; it would give you an easy step-by-step guide to find the problem area.
I'm working with a printed copy of it. That's where I found it -> http://www.zimmers.net/anonftp…ters/pet/2001N/index.html
The monitor looks okay to me. I guess it is free-running (not synched), as it does not get a valid signal.
The monitor is fine. It was tested and found working. Running unsynched? Good, that's really the kind of point I was seeking. The few characters displayed are seen correctly, I guess that this means that "Horz Drive" is ok and I should look for "Vert Drive". Suspects are, for now: G10 (74LS00) and H8 (74LS107); both of them in sheet 6. If found working then G8 (7474), G1 (74LS08), H5 (74LS00), I1 (74S04) and G2 (74LS20); all of them in sheet 7.
For the testing, sync signals can be obtained at the user port easily.
The dot after turning off is an old commodore flaw that provides for ugly burn-in holes in the screen middle.
There are fixes for that available in the web.
Yes, I know what it is and what it does. We call it "el punt verd de la mort" (the green dot of death) and I have other monitors that have this issue. What I didn't know is that there is a fix for them. I searched but cannot find the solution. Could you point me where could I find it, please?
Many, many thanks.