my robotron upright quit working

[qbertandernie]

the machine was running fine, i had finished playing about 10 mins before and it was just displaying demo stuff. i walked by to let the dog out, opened the door and came back - literally like 10 seconds - and the screen was black. :(

the screen still has power to it, it will fire up but just displays a black screen.

the sound still works, i reset a button in the back and a demo song came on.

there was a red led display light that said "0" on the back panel(visible with the coin door open) that is now out.

i replaced all of the fuses i could see and nothign changed.

Any suggestions?

[Flack]

If you turn the machine off and wait a day or two, does the monitor come back on? If so, it could be a bad capacitor. If not, something blew.

I don't know anything specifically about Robotron, but general advice would be to first install a capkit on the monitor, and if that doesn't work, start looking at ways to get the monitor repaired and/or replaced.

98pacecar might have some more advice, I know he's worked on monitors in the past.

[FABombjoy]

the screen still has power to it, it will fire up but just displays a black screen.

...

there was a red led display light that said "0" on the back panel(visible with the coin door open) that is now out.

You don't happen to have a service manual do you?

If the display is black, how do you know it's on? Can you still see faint scan lines on it? If not, what happens when you crank the brightness control up?

The LED thing is probably unrelated to the monitor itself, and the fact that it is unlit signals a potential board problem. Does inserting coins & pressing start cause game sounds to play?

[qbertandernie]

i printed off the service manual from KLOV.com last night but havent had a chance to check it out. there are faint lines on the screen when i turn the unit on, and the marquee lights up. the manual did say that the LED should be lit to let me know the problem, so i figured thats where the lack of power is coming from
(maybe the monitor is getting power but the board is not?) i checked all of the fuses i could see, but only one seemed blown and i replaced it with no apparent change.
contact to the quarter slot doesnt make any noise, but the stupid demo song will play incessantly while im trying to track down the problem..

i havent plugged it back in in several days, maybbe itll fire up when i try again. thanks for the advice, ill keep posting if i find any other possibilities or if it starts working.

[FABombjoy]

The opening sound effect plays continuously? That's the same sound effect for when you've gotten another life, right? If it keeps playing repeatedly, it sounds like the board is resetting itself over and over. The fact that the diagnostic LED is completely unlit points to a board problem, especially if it is supposed to be lit all the time.

If you can see faint lines on the screen when powered up, then I doubt the monitor has anything to do with the problem. The game should still play and sound as normal even with a blown out monitor. You could disconnect the RGB connection to the monitor to verify that it is not the cause.

Have you made a physical inspection of the boards?