PCjr Monitor Adjusts

[Sharkey1331]

Revive of old thread!
I *FINALLY* got a real PCjr monitor!!! Bought it local no less, from a dude near York PA who is liquidating his warehouse from an old PC business. I paid $45 bucks. Not sure if anyone is near there- but he had a VERY nice, complete PC AT with the model M keyboard, monitor, etc. for $400-ish dollars. 2 PC convertibles there two, two 1541 commodore drives, other odds and ends including an Osbourne "portable" PC.. Anyways- if anyone is near and wants the contact info, let me know. He said he would not ship. There's 1 more PCjr monitor there, and several (many) IBM monitors..

Anyways, the unit I bought powered up in the shop, and looked decent. I brought it home, cleaned it up, and it looks physically very nice. Plugged it into the PCjr- the colors are amazing! BUT, it looks like it might need some adjustments? Picture seems a bit too small (it is not stretched all the way out to the edges), and the top-left corner seems to be a slight bit closer to the top of the case than the other corners. Maybe I am being too "detail focused" and it is fine? What do you guys think?




If it is out-of-adjustment, do you think this indicates a cap job needed, rather than actual adjustments? What do you guys think?
Jason

[Chuckphd53]

there is a HORZ center adj on the yoke board, R434 , but if you are going this far, then Yes recap and touch up all the solder joints on the yoke and other large components
as these tend to get solder fractures from shipping and time. especially the main bottom board with the flyback txfrm it is usually a hot spot.
Just be prepared to go slow and cautious, take PICs of all the cables and connectors for placement and orientation.
Ive done a couple Jr monitors and they usually come back to life as good as new.... my experience, you mileage may vary...
Chuck

[Chuckphd53]

just wanted to add....
As most already know..

If you delve into the Monitor, be sure to use caution, the High Voltage Flyback, generates 1000's of volts, and even when turned off
it can and does hold a charge... be sure to discharge it ( you can youtube search how ) it quite shocking if you dont...

also since you have to adjust the Horz with it turned on, you NEED to use a non- conductive tool, (no metal)
they make plastic tuning tools for this purpose,

and with the case off and monitor turned ON , caution, use one hand only, one in your pocket.
If you have not worked on a tv or monitor, you should get help and watch some youtube videos....

chuck

[Sharkey1331]

Yup- I appreciate any and all voice of caution! This hobby should be fun, not painful or scary!

So, I think I'm gonna remember some advice my grandpa told me way back in the day; if it ain't broken, don't fix it! At least, it appears to be working pretty well for now. When I get some more spare time, I think I will dis-assemble it, clean it inside and out, and re-cap/adjust it.

But for current use: The colors are bright and stable, there's no sizzling sound, no buzzing in the speaker, and it's not smoking/smelly. I think it's probably safe to use until any of those mentioned characteristics change!

I gotta say- after trying to use a composite LCD solution, and a cheapo composite->VGA converter... WHAT A DIFFERENCE! This CRT looks beautiful! Just makes you want to use the computer more!

Jason

[Chuckphd53]

I agree, the CGA2RGB is nice, but far from clean and crisp.
But you have to like the old style char. generator on the Jr monitor characters, which I actually do...it is very hard on the eyes long term but it is crisp...

If you do tear it down at some point, I have used Fabuloso (homedepot and others have it) to clean and de-grease the plastics.
I used a semisoft brush to get in the hard to get places especially, but it works great on the overall semi smooth surfaces very well...
My Jr monitor was rdy for the dump (visually) but it looked like it was right out of the box, after cleaning...
Just FYI as I have seen the 8-bit guy use all sorts of soaking for yellowing etc. Fabuloso works good for that too... and it is not expensive.

Chuck

[DoctorOctal]

Picture seems a bit too small (it is not stretched all the way out to the edges), and the top-left corner seems to be a slight bit closer to the top of the case than the other corners.

From what I can see in the photos, the picture looks fine. The text isn’t supposed to go all the way to the edges of the screen, nor should you expect it to be exactly centered. In fact, you may notice a slight shift in position when changing from one screen mode to another.

On my primary Jr monitor I’ve increased the vertical size a bit (using the knob in the back) to correct the aspect ratio and get perfect circles, but that’s a matter of personal taste.

CRTs are imprecise beasts compared to LCDs driven by digital signals.