Re: TECH: Sys7 Display help

On Jan 21, 1:49 pm, sgerde...@xxxxxxxxxxxxxxxxxxxxx wrote:
On Jan 21, 7:46 am, seymour-shabow <seymour.sha...@xxxxxxxxx> wrote:





sgerde...@xxxxxxxxxxxxxxxxxxxxx wrote:
Have a sys7 Cosmic Gunfight I'm trying to bring back to life.  None of
the displays work.

Game boots up and plays a game, solenoids work.
Fuses on pwr supply are good.
Pwer supply voltages are good.
Blanking signal at 1J3 pin 4 on the CPE measures a little low at 3.6v..
Same reading at 40 pin connector.

I've been trying to get thru the marvin section on this and all I've
done is confuse myself.  Any ideas on where to focus?

Got any other machines that take those displays?  Can you try them out
to make sure they're good/take the display driver board out of the other
machine, test in the CG?  (Board attached to the inside of the insert panel)

-scott CARGPB#29

This is the only sys7 game I currently have.- Hide quoted text -

- Show quoted text -


Sgerdeman

In my book, I would have thought blanking is OK if the solenoids and
lights work and you can play a game. Does sound like blanking is good
but the voltage is low.

Hmmm... all displays are out, probably not the displays then...

1. Start wirth the basics, F1 fuse on the power board (PSU) is a .25A
(1/4 Amp) Slow blow fuse from memory. Use only whatever value the
game needs.
Take the fuse out and examine the fuse clips, measure the fuse outside
of the game.

2. Try turning off the game and connecting only one display at a
time. Say, player one and 4 digit credits? Turn it back on. Or just
connect a single player display on it's own? Again remove and aonnect
displays only with power off. A bad display may stop all the good
ones from working.

3. You may also have a HV fault (I think +100v and -100v goes to the
displays) from the PSU, is there a faint orange glow (some say they
see a "dot" in the glass if you look close) of any displays? If no,
again no displays at all. I know you say voltages on the PSU are good
but how close are you? Is it +/-90v + ???

4. The Display Driver board (behind the insert panel / door) is faulty
or not connected up right? Reseat all the cables especially the
"edge connector" one. Orentation of the red stripe on the ribbon
cables is always towards "pin 1" of the display (or sometimes it is
denoted by a printed triangle shape).

5. Arrgh. It's your Sys7 CPU board. Could be IC18 (a 6821 PIA at
middle right abovbe RAMs) is bad which controls the Displays ? And
it's pulling down the blanking. You could swap it with the same 6821
PIA at IC38 above, which controls sounds and display commas to check.
You should get some displays but no sound calls. Do this If both PIAs
are socketed that is, if not don't bother Just check the PSU voltages
again and if OK, send the CPU board to someone for repair.

PSU Voltages to check and post:
3J5-1 Ground Reference
3J5-2 no connect
3J5-3 -100v DC **Careful**
3J5-4 +100v DC **Careful**
3J5-5 no connect
3J5-6 +5v DC

I had trouble posting this reply on google, so apologies in advance if
it is duplicated.

Cheers

-Richard
.

Relevant Pages

  • Re: TECH: Sys7 Display help
    ... Pwer supply voltages are good. ... Blanking signal at 1J3 pin 4 on the CPE measures a little low at 3.6v. ... to make sure they're good/take the display driver board out of the other ... Slow blow fuse from memory. ...
    (rec.games.pinball)
  • Re: Gtb. Amazon Hunt diagnosis
    ... If your voltages are good, the display issue could be a flaky ... one bad display could be dragging them all down. ... solenoid fuse is fine. ... and both DT reset coils. ...
    (rec.games.pinball)
  • Re: What kind of part is this?
    ... > Working on a sony PSOne video display with no documentation. ... > First problem was a tiny fuse of some sort; ... I would say that it is almost certainly a diode, and if it's right after the ... Assuming that it is a diode, and even being a surface mount type, it should ...
    (sci.electronics.repair)
  • Re: microwave - no power
    ... there was no power - the display was dark and nothing I could do on the ... What is the likelihood that it's just a blown fuse, ... 15 years ago I had a microwave that failed like that. ...
    (alt.home.repair)
  • Re: UL & fuse rating
    ... The fuse I've selected is a 5mm pigtail, 1.5amp fast action rated at 250V. ... Your label ratings are the problem - they should reflect AC nominal ... subtracts margins for evaluation to reflect typical line voltage ... voltages plus and minus similar margins. ...
    (sci.electronics.design)
Loading