Sys 6 Firepower Display issues

[TUF-427]

Ok got a couple of display issues on the Firepower,

borttom line out on 1-2 and credit displays which is prob connection or dry joint somewhere ?

also now score 3-4 are all 8s but will score if played but numbers arent fully correct if that makes sense..

Master display board is the earlier one with the transistors over the later Ics which I guess should be easier to repair..

this things been a pain ever since ive moved house!

Picture tells a thousand words...

[beaky]

i would first disconnect each display one at a time to make sure there are no shorts in the displays them selves. (turn machine off, disconnect player one display and turn it back on. then plug player one back in and do the same with player 2 and so on)
I have had situations where there was a fault with the one player display and it caused problems with both player one and two.

[TUF-427]

Cheers for the reply Andrew,
Will give it a try and report back.
The missing segment problem seems to appear once the machine warms up ,
Sometimes all ok when first turn on.
All the 8s are a new problem that's there solid now...
Peter...

[Mr Pinbologist]

I have had situations where there was a fault with the one player display and it caused problems with both player one and two.

+1 i have come across this several times, where a fault in one of the display glasses causes segments to go out in other displays. Had that problem on my Flash when i got it up and running.. segments out on the master display and players 1 and 2. It ended up being a bad display glass on the master display itsself causing the problem.

Havent seen the all 8s fault before though, that a new one to me   I would still try beaky's suggestion for the 3 and 4 player displays as well. could possibly be a bad glass affecting the other

[TUF-427]

ok disconnected each display seperatly,no change unfortunatly...

Geez I hope its not the master display shorted ! sounds like the same fault you had tho..

Ive got a hunch on all the 8s, theirs 2 Bcd to 7 segment decoders MC145437 on the discrete component master board,

one runs displays Master + 1-2 and the other displays 3-4,

will swap these Ics and see if the 88888888 fault moves...

[Retropin]

If all 888888 then yes id be going straight to the BCD chip.
Missing segments on 2 displays more likely a connection issue or it is possible the same resistor is out on both display boards

[beaky]

Make sure you socket any I.C. you remove.
it will make things easier to replace in the future.

[TUF-427]

thanks for the comments and ideas guys..

I swapped the Bcd chips to see if the 88888 fault  moved ,

and cycling the chips in and out of the sockets fixed that issue,

I removed the Master display board and tested all resistors etc and looked for dry joints,

found a few possibles but didnt fix the missing segments unfortunatly..

Wonder if it originates from the Cpu board on the display drives plug connectors?

[beaky]

if its a  constant fault it could be one of the other chips on the master display board if you find the fault is not in the wiring or plugs.
Or it could be a faulty PIA chip on the cpu.
If it is intermittent then it is more than likely a wiring problem if it is not a problem in the glasses.
 

[TUF-427]

Was playing the machine for a couple of hours today,

and the missing segments actually starts to come back once its on for awhile...

will pull the cpu and have a look there I think..