View Full Version : Asteroids shifted off center on monitor
Dokert
02-03-2009, 09:13 PM
My Asteroids picture shrank by about 2" and shifted off center down and to the left.
Monitor is a G05-802 that has been tested in another machine and is working perfectly.
A/R I is dead up nuts on +5.01vdc
Replaced both the + and - 15vdc regulators, and the picture size returned to normal. Video is still shifted down and left.
Test comes up shifted down and left. X and Y adjustments work as they should in both directions.
Lost, any ideas?
spanks_4
02-04-2009, 03:48 AM
Yep it is broken. Sorry no further help from me *this is why I am anti-vector*
Lindsey
02-04-2009, 05:17 AM
Monitor is a G05-802 that has been tested in another machine and is working perfectly.
Did you test the board in another machine?
Dokert
02-04-2009, 06:59 AM
No, I haven't.
Lindsey
02-04-2009, 07:01 AM
Might want to consider that if it's a possibility. Narrow down the problem a little more.
mspaeth
02-04-2009, 07:05 AM
...so install the parts listed shown as unpopulated in the schematics that control centering and center the image...
...or fix your deflection board... sounds like the 3.9ohm resistor is jumpered for one rail and not the other.
modessitt
02-04-2009, 01:25 PM
If you're picture can be adjusted to the proper size, but is off-center, and you're sure the deflection board isn't the issue, or the game PCB, just turn the centering tabs on the yoke to adjust the picture center back to the center of the tube....
Dokert
02-04-2009, 03:15 PM
If you're picture can be adjusted to the proper size, but is off-center, and you're sure the deflection board isn't the issue, or the game PCB, just turn the centering tabs on the yoke to adjust the picture center back to the center of the tube....
I believe this to be a game pcb issue. Noticed that the lines in test are jagged but straight if that makes sense. Can't seem to get a decent picture showing the test screen in relation to the edges of the tube.
road.runner
02-04-2009, 03:34 PM
I've seen this caused by a bad TL082 in the output section (or was it a 4016?) I will check my notes. Try piggybacking a known good chip and watch for any change in position
arcadejunkie
02-04-2009, 04:52 PM
this is the one that did this when i was there correct? it looked good then all of a sudden bam tiny picture. i just realized i added nothing to this thread http://forums.lymphoma.com/forums.arcade-museum.com/images/ubbgraemlins/tongue.gif
Dokert
02-04-2009, 04:55 PM
this is the one that did this when i was there correct? it looked good then all of a sudden bam tiny picture. i just realized i added nothing to this thread http://forums.lymphoma.com/forums.arcade-museum.com/images/ubbgraemlins/tongue.gif
Yes, replaced + and - 15vdc regulators and size returned to normal, but is still off center.
road.runner
02-04-2009, 06:35 PM
Checked my notes...it was a bad TL082 that was causing the test screen to be offset down. Must have been introducing a bias voltage to the Y OUT.....replaced it and all was well.
Dokert
02-06-2009, 06:14 AM
Ordered both the TL081's and TL082's, and all of the caps.
Brick Top
10-15-2009, 04:15 PM
Ordered both the TL081's and TL082's, and all of the caps.
Dokert,
Did this fix the problem? I am seeing the same thing with an AD machine.
Dokert
10-15-2009, 04:35 PM
Dokert,
Did this fix the problem? I am seeing the same thing with an AD machine.
Made it better, but did NOT completely cure the problem.