(Topic ID: 272682)
Linked Games
Black Knight
Williams, 1980
Topic Gallery
You're currently viewing posts by Pinsider PINTEC.
Click here to go back to viewing the entire thread.
Chicago, IL
Quoted from WonderMellon:Sure thing. Here is the whole driver board and the switch section. The 2 large resistors are the ones I replaced thinking the original ones were bad. They are still 4.6k ohms, but rated at 1watt.
I tested each 2J2 pad to ground. All read 4.5volts except for 3 and 5 (ignoring the key spot)
I then tested the pad of each resistor closest to the header pins and every resistor reads 4.6volts. I thought the resistor lead straight to the header pin, but looking at the schematic you uploaded, that does not appear to be the case. Not sure where to trace the voltage back to see where it is being lost.
I very much appreciate your help with this. As you can see, I am quite lost.[quoted image][quoted image]
The 2 signals that arrive at IC 18 are generated from PIA 11 Check pins 16 and 15 which must be pulsing in game over mode.
No? Suspect PIA 11 failure
Also recheck and add additional solder at IC 18 pins 1-2 5-7 and re check pins 8-14
114 (resized).jpgI did a continuity test from the PIA to both 7406 chips, both chip pins and socket pads. The good news is that my solder job was good.
The bad news comes when I pulled out the logic probe. Pins 14 and 15 of the PEA had no voltage. It was not low, or high; just nothing. I assume that means the PIA is bad. For the record, here are the results of the first 1/2 of the PIAMissing signals replace PIA 11
Promoted items from Pinside Marketplace and Pinside Shops!
You're currently viewing posts by Pinsider PINTEC.
Click here to go back to viewing the entire thread.
Reply
Wanna join the discussion? Please sign in to reply to this topic.
Hey there! Welcome to Pinside!
Donate to PinsideGreat 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+!
