Mike's PCjr Page

jmetal88 wrote:Man, I wish I could look at it in person... I bet I could diagnose the problem if I could. I doubt we live close enough, though. Never ran into anyone else on any of these forums from the Kansas/Oklahoma area.

So close but so far. I live in around this red dot

Eric wrote:

jmetal88 wrote:Man, I wish I could look at it in person... I bet I could diagnose the problem if I could. I doubt we live close enough, though. Never ran into anyone else on any of these forums from the Kansas/Oklahoma area.

So close but so far. I live in around this red dot

Closer than I thought (couldn't see the image embedded, but I followed the link). But still a ways away. Would've been a lot closer when I still lived in Pittsburg, but my new job is closer to the Wichita area, so that's where I went.

Is there anything I should try? Should I take pictures and record stuff? Maybe post a 4K video?

I feel that I'm at the point to where I can use a little hand-holding. Not spoon-feeding, but you know.

Well, my approach would be to take a multimeter and just follow the power into the monitor (being careful not to shock yourself, of course), through each component, looking up datasheets for anything I'm not familiar with, until I reach something that's not doing what it's supposed to. It's hard to be much more descriptive than that, since I haven't been able to locate the schematic.

jmetal88 wrote:Well, my approach would be to take a multimeter and just follow the power into the monitor (being careful not to shock yourself, of course), through each component, looking up datasheets for anything I'm not familiar with, until I reach something that's not doing what it's supposed to. It's hard to be much more descriptive than that, since I haven't been able to locate the schematic.

I'd try that, but there's an RF shield or something in the way of the solder mask (The components are mounted on the other side) and it's hard to follow the traces to there.


I also tried to locate some schematics on it, but there numbers screened on to the PCB aren't yielding any results through search engines, though I'm not too surprised.

the PCjr Technical Reference Guide on oldskool has the PCB schematic for the display.

geoffdaddy wrote:the PCjr Technical Reference Guide on oldskool has the PCB schematic for the display.

The reference has that? I wasn't sure if it would, but I'll have to check it out.

I'll have to check mine. For some reason I was thinking it was the PC Color Display that had a schematic in there rather than the PCjr Color Display.

jmetal88 wrote:I'll have to check mine. For some reason I was thinking it was the PC Color Display that had a schematic in there rather than the PCjr Color Display.

Ah ha! I'll bet you're right. I didn't notice that. The manual talks about the IBM Color Display in the sections before it and mentions that you must use the adapter cable to connect it.

geoffdaddy wrote:

jmetal88 wrote:I'll have to check mine. For some reason I was thinking it was the PC Color Display that had a schematic in there rather than the PCjr Color Display.

Ah ha! I'll bet you're right. I didn't notice that. The manual talks about the IBM Color Display in the sections before it and mentions that you must use the adapter cable to connect it.

Probably. Weren't most of the publications and the PCjr itself released a significant time before the color display became available and usually always mention the IBM color display? Doesn't mean it wouldn't have it, but…


By the way, does anyone know if the boards are similar?