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Author Topic: Help- baby PAC vidiot board  (Read 1195 times)
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b.moore2011
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« on: January 13, 2017, 11:21:47 pm »

Just picked up this PAC. Start the game up, led on vidiot board blinks 8 times. I found some info that says ""The 6809 CPU chip at U8 attempts to test the VDP (Video Display Processor, which is the TMS9928 at U16). If there is no ninth LED flash, the TMS9928 at U16 is bad."". I tried pulling the chip, cleaning the legs, and reseating the chip. I checked for continuity from the top of the chips leg, to the solder point in the bottom of the board. Still the game won't pass this point. Thing is, the game wasn't working past the EPROMs earlier. I cleaned those and reseated them, and for a few, I got the game to actually play. But now it won't show anything on the screen.  Anyone have any tips? Only other thing I see is there is a resistor and small cap installed across 2 pins of that chip on the bottom side of the board.. don't know if this is normal.
https://imgur.com/gallery/fWCdCO
« Last Edit: January 13, 2017, 11:26:44 pm by b.moore2011 » Logged
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