Re: Stuck output(s) on G80 X/Y Cards / CPU no LED.

Anyone have any ' good ' methods for troubleshooting SEGA G80 CPU and / or - X/Y Timing / Control - Cards?   I also wonder if I may have a Watchdog issue on the CPU Board itself?   But if the X/Y Cards provide clocking to the CPU Board and if these are not functioning correctly, then I suspect the CPU may never come up.   Again appreciate any ideas that anyone can offer.   Thanks,   Sent: Tuesday, January 10, 2012 9:59 PM Subject: VECTOR: Stuck output(s) on G80 X/Y Cards / CPU no LED. >I have three sets of Sega G80 X/Y Timing and Control Cards.  >All three sets of the ' Timing ' Cards remain stuck a constant voltage  >output in the range of 1.50 to 1.66 VDC. Also the ' Control ' Card output  >remains at 0.16 to 0.22 VDC on all three ' R G B ' ouputs. I suspect that  >this may be the reason that my CPU card will not come up, and the CPU's >LED remains off. I have replaced the crystal, on the CPU card, Z80 CPU >along with memory (2114) on both the X/Y and CPU Cards. I also replaced >the LED, itself. So far I get no output and the CPU seems to be non functional. >As a sidenote, I am using an Original Sega G80 power supply / transformer. >All voltages(including the Reset power on voltage) measure as ' Good ' . >Appreciate any ideas that anyone can offer. >Thanks,
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Received on Tue Jan 17 09:46:55 2012