I am hoping someone can share some knowledge.

I recently obtained an unpopulated Gottlieb display board from The Pinball Resource (PBR). It is listed on PBR as a Gottlieb System 80B board. When I Compare it to the board in my System 80B pin it appears the same with the exception of a capacitor added at C7 (see attached photo).

I followed the circuit from it where it enters at A4J1 to it’s end at the display glass . The circuit, as far as I can tell, is the same as the circuit from in the Gottlieb manual (Chicago Cubs Triple Play, CCTP). There in one exception that I see. That is a capacitor added between the incoming input from A4J1/#10) and Z2/pin 9.

I highlighted the circuit on the board from PBR (see attached picture). The outgoing path on the PBR board from Z2/pin 8 to U2/pin 5 is the same as the the schematics for board CCTP A4 board.

Since the CCTP schematics does not include C7, I am unsure of what capacitor could be used. If the board is populated with components per the CCTP manual, can C7 be left unpopulated? If not, can someone suggest a suitable capacitor?

Thanks,
Phil

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Thank you very much!

Thanks Ed and YeOldPinPkayer for catching my mistake I guess I shouldn’t work late into and into the early morning hours.

Hi Chris,
I don’t remember where I got the 10939 chips but, I got the 10941 from Ed (a couple years ago) he is out of them now. I did a quick search and found these vendors: ( there maybe more)
flippers.com. List both the 10939 and 10941. https://flippers.com/catalog_oc/index.php?route=product/search&search=10941

Marcospecalties lists both just search on the IC number: https://www.marcospecialties.com/control/main

Arcade Chips only lists the 10941, https://arcadechips.com/advanced_search_result.php?search_in_description=1&keywords=10941&pfrom=&pto=&categories_id=&x=0&y=0

I do not remember where I got mine. I have had the stored away for awhile. These two vendors show them in stock.

Action pinball lists them: http://www.actionpinball.com/parts.php?item=XO-840

Marcospecialties also has them: https://www.marcospecialties.com/pinball-parts/GTBDIS20-T