asteroids video question

[Scoots]

seems my monitor is shrinking! i didn't realize it at first, but i was cleaning under the glass (cocktail cab) and with the smoked plexi out of the way you can see where the screen has burned in. the total displayed image area was obviously once bigger than it is now. this isn't a major flaw right now but if it were to continue i definitely wouldn't be too psyched.

i found this on an asteroids repair site:

11. Problem: Display only visible in a very narrow vertical band in centre of screen, some activity can just be seen in the band (revision 04 board).

Fix: TL082 op amp at C12 had been removed, as well as the two capacitors at C98 and C119 (220 pf radial lead epoxy dipped 100V Mica capacitors). Replaced.

this seems to be an extreme version of what i'm dealing with. anyone else have any experience with this issue? any feedback would be appreciated.

[Arcade Antics]

Has the monitor been recapped since you got the machine?

[Scoots]

no, i've only had it for 3-4 weeks and the previous owners were not game/tech people, they just lucked into an arcade cab. the only repair i can tell that has been made is that the chips at C4 and C5 (i think, i'm going by memory here) were replaced at one point (i'm assuming since they were definitely not factory soldered).

i don't think i want to get involved with a full recap if it's avoidable. i'm an "ok" hand with a soldering iron but i'd be wary about my results on such a precious machine.

[Arcade Antics]

i don't think i want to get involved with a full recap if it's avoidable. i'm an "ok" hand with a soldering iron but i'd be wary about my results on such a precious machine.
Can't say for sure that a recap would solve your problem, but if it was my machine, that's the first thing I'd do. Maybe order a cap kit and pull the monitor, see if the caps listed in your first post are easier to get at and go from there. Or if you've got a friend who can help out with the soldering, cap kit is always a good idea, especially on machines that are 28+ years old. ;)

If you do recap it and it's not any better, you can move on to the next item on the troubleshooting list. And when it's all fixed up, the new caps will make it look like new.

[Scoots]

thanks for the input. i know recapping is the "right" thing to do, but like everyone else i have 100 projects going on simultaneously 24-7-365 so i have to pick my battles. from a time/money standpoint, getting it exactly right the first time is the way to go.

[Scoots]

i don't believe that there are any horizontal or vertical controls. none that i could find anyway.

[chadtower]

There is no reason for them on a vector, since the electron guns don't scan.

Cap kit is the first thing to check, since it's probably something in there. It needs a cap kit anyway or it will continue to deteriorate with use.

I also always recommend replacing the power supply filter cap on any old Atari cab. Those go bad and you start seeing all kinds of problems, plus is places more stress on your voltage regulators and diodes.

[chadtower]

Telling someone not to cap a 20+ year old arcade monitor is like telling someone not to replace the original tires on their 125,000 mile car.

If you don't do it, they WILL fail, and soon.

[Scoots]

i see your penchant for hyperbole is intact, chad.

[chadtower]

It is, but I don't consider this one hyperbole.

[Arcade Antics]

Telling someone not to cap a 20+ year old arcade monitor is like telling someone not to replace the original tires on their 125,000 mile car.

If you don't do it, they WILL fail, and soon.
He didn't tell him not to recap it though. He just said that if the current problem is the adjustment pots, it won't matter if the caps are old or new. ;)

Given that Scoots is looking to invest as little time/money as possible right now, that's the best advice on solving the problem. He can always recap it later on when he's not so busy.