Another update on this old thread. Everyone’s previous comments were extremely helpful.
I finally dug more into this chassis and followed the Randy Fromm flowchart. In the end it turned out that IC501, the STR381 voltage regulator which clearly had been changed on this chassis prior to my...
Hey all!
Realized I never followed up with a resolution on this. But for those doing future research, I followed the advice from @jjhudgins and changed R80 to 3.3 Ohm, and also replaced the shot C51.
After doing that, I was able to get the image to about 95+% the full height of the screen...
Spotted this this morning on FB. I’m not in the market for another project but it looks like the game boards are present and the last pic shows a monitor frame and I see a flyback, so looks like the monitor is present. Seems to me like a good price for a Tempest that may only need a coin door, a...
Hmm, thanks, good to know. I had to use that on APB because that’s what Atari originally used on that game — although no doubt the currently available stuff is probably of lower quality than the original Atari stuff. But maybe I’ll do something different for Afterburner then so I don’t temp fate...
Someone else pointed out I should put a blue coin reject plunger on the blue side of the coin door. Need to order one of those… Twisted Quarter sells them.
Did yellow on my 1943 to match the Numbskull 1/6 scale as I thought it looked sharp. The red/blue motif on Police Trainer works with the guns, and chrome on APB is what it’s supposed to have.
I’m planning to do chrome on my Afterburner as well, and saw someone else did a light sky blue on...
Update: After swapping the incorrectly installed cap with a fresh one, the picture looks great, is the correct size and is stable.
The cap that was installed wrong still tested a good ESR and at the rated value, but it was physically bulging on both ends so I did not attempt to reuse it. I’ll...
Well, I think I probably found the problem. Dammit. Seems double-checking polarity wasn’t enough.
I powered it back on and the image actually looked fairly stable but after 45 seconds I saw a whiff of smoke and spotted the cap bulging.
Guess I’m raiding the other 4900 cap kit I had on hand...
I also just remeasured the yoke since the flowchart mentioned a vertical deflection problem. Yoke measures 40.5 Ohm on Yellow-Green and 3.4 Ohm on Red-Blue
Hello!
I have a K4900 4-pot that came in a Williams cabinet I bought a while ago for restoration. It did work when I bought it although the picture was washed out. I decided to recap the chassis while doing the other restoration work. I also tested the tube on my B&K and it tested very good so I...
I know these are uncommon but I’ve seen a few sold here in the past couple months. If anyone has a Nintendo Vs/Playchoice light gun for sale, please reach out.
Just picked up a PlayChoice with a modded Zapper. It works but it would be cool to get the correct original part.
Thanks!