First post, by ints99
Hi, any suggestions?
There is the following problem on an otherwise clean (no battery damage + battery replaced) motherboard:
After about 10 minutes of use, Check-it 3.0 starts reporting DMA problem "Controller #1 failure" etc.
It seems that with more time, the error also starts to be more specific (also error on controller #2; specific DMA channels reported as failed...).
The total memory of the 1MB (4 pcs of SIMM, 70ns) seems to give slightly less errors, the 4MB -80 and -70ns SIMMs will trigger it faster (if not immediately).
Assuming I've tested it with a 3 or 4 different sets of SIMMs and basically just the CPU and Headland HT12/A chips are on board - should I assume that either the CPU or the HT12/A needs to be replaced to fix it?
Add a picture of the board:
