I've usually found that the buffer ICs have issues when you get a bad beep. So I'd change the 74LS245/373's on the RAM/ROM address or Data buffers - starting with the data buffers. Or grab a Fluke 9010A and the correct pod and troubleshoot professionally... John :-#)# At 7:14 PM -0500 6/9/05, Bill Karkula wrote:
I worked on four Missle commands for the first time and got three of them working (what a design - not designed for easy hardware debugging). The fourth board has me stymied. It comes up with one high beep for one of the 4116s being bad which I have replaced twice but the error still comes up. If I intentionally remove any other drams the correct beep error is caught. I've checked continuity to the suspect Dram but all is fine. I've gone over all of the sections of the board and they all seem to be working but the board as a system won't come up. It just keeps looping the dram beeping test. Any suggestions based upon your collective experience would be welcome.
Thank You and Best Regards,
Bill
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