Flash
Williams, 1979The bottom row of segments are out on the display master board, player 1 and player 2. However player 3 and 4 are perfect. I narrowed it down to only the display master board by swapping it with a known good. It is also intermittent which makes it harder to find.
See photo that is attached.
0127202018_HDR.jpgAre you handy with a logic probe or scope?
Its probably IC5, IC9, and/or R4 on the master display board.
Remove the display fuse from the power board. Check IC5 segment D output, P12 for pulsing during display test. If missing replace IC5 (CD4543 replaces the MC14543). If IC5 P12 is pulsing R4 is open/burned or IC9 is bad. When the resistor burns that is usually an indication of a bad display or bad IC9. Don't recommend probing IC9 the 5v level to high voltage level chip... I pretty much make sure the 5v side is working correctly than do the HV part if needed.
In your opinion other than bad solder that I cannot find any...... It is hardly doing it. Had the game on 2 more hrs last night and two this morning and it's not doing it.
It could be a bad display like Chad said. I had a bad display damage a master display board segment circuit two times before I finally found it was actually a display doing it.
See if the series resistor after the the UDN7180 IC9 chip is overheating compared to the other resistors. If so you may want to try one display at a time looking for the one consuming too much current. Careful as there is high voltage at these resistors, so no touch with the power on.
To confirm the displays are all good. I have two games that have the same system. The problem follows the display master board or whatever Williams calls it.
I will check the resistor. Any chance a chip could be aging and starting to fail.
Quoted from Fordiesel69:To confirm the displays are all good. I have two games that have the same system. The problem follows the display master board or whatever Williams calls it.
I will check the resistor. Any chance a chip could be aging and starting to fail.
Integrated circuits and active parts don't normally fail intermittently, they either work or they dont for the most part. Might have questionable soldering somewhere. Wouldn't think its an output connector since the display on the MDB acts up too.
Wanna join the discussion? Please sign in to reply to this topic.
Great to see you're enjoying Pinside! Did you know Pinside is able to run without any 3rd-party banners or ads, thanks to the support from our visitors? Please consider a donation to Pinside and get anext to your username to show for it! Or better yet, subscribe to Pinside+!
This page was printed from https://pinside.com/pinball/forum/topic/williams-flash-display-issue and we tried optimising it for printing. Some page elements may have been deliberately hidden.
Scan the QR code on the left to jump to the URL this document was printed from.
Green Brook Township, NJ