Monitor Acting Funny

[Tempest]

I had my PCjr unplugged for a while, so when I went to plug everything back in today I discovered my monitor is being weird. I get a lime green picture with some distored lines rolling across the screen. I assume the cable plugs in with the D side up? When I plugged it in the other way all I got was a black screen so that must be wrong. What on earth could be wrong with my monitor? Please tell me it's not dead.

[Tempest]

It looks like the monitor is trying to display the colored bars, I can sorta see them, but they're all distorted. When the next screen comes up (some kind of text), what should be a black background is a lightish green. Everything is still distorted so I can't see what's going on.

The last time something like this happened, I had s bent pin on the port, but I'm not seeing anything wrong with it this time. Could I have accidentally fried something plugging it in wrong? I sure hope not...

[Brutman]

Can you post a few pictures or even some video? It would help us figure it out ...

[Tempest]

Yeah I can do that tonight. Basically the picture looks like it's there, but one of the syncs are wrong. The image is distorted into little lines diagonally going bottom left to upper right. The black is also a greeny black instead of the solid black.

Can someone confirm the correct orientation of the cable? Does the side with the D go up or down?

[Trixter]

The shell has two lips on the top of it that are supposed to prevent you from plugging it in the wrong way. I guess if you apply enough force you can smash past that limitation (!) so stop doing that. The "larger" part of the plug/shell should be oriented towards the top of the PCjr.

[Tempest]

I read somewhere that the earlier versions of the PCjr didn't have that lip or it wasn't as pronounced, I think I must have that version because it goes in easily either way.

[jmetal88]

It's easy to plug mine in upside-down because the divider between the ports actually fell out.

[Tempest]

I got it working. I guess I didn't have the cable plugged in all the way or it wasn't aligned properly. Everything is good now.

[Tempest]

I'm still having a bit of strangeness with my monitor. The picture seems to want to slowly roll at times. I can get it back to the right spot with judicious use of the vertical hold knob, but it seems to want to go back to slowly scrolling up or down the screen after a while. I'm assuming this is because I fiddled with the knob and it hadn't been used in about 20 years, so maybe it's dirty? Any way I can fix this?

[Brutman]

You can try exercising the vertical hold knob a few more times to break away whatever other cruft/oxidation is in place. If it really is just dirty/oxidized Radio Shack sells a can of some chemical nastiness called "tuner cleaner" which is designed to clean switches and potentiometer type knobs. You will need to get good access to the know internals and wear eye protection because the blast is quite powerful and the overspray is dangerous to eyeballs.

As for the connectors on the back of the machine ... everybody needs to be really careful with the pin orientation of their connectors. Fixing those motherboard pins is a nightmare.


Mike