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X68000 PRO CZ-652C Schematic to aid repair

Started by ejb, November 25, 2019, 08:13:39 pm

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ejb

Hi Folks

I am looking for the schematic for the X68000 PRO - CZ-652C.

I am restoring this machine and have
- Made a X68000 to VGA Cable
- Replaced the SRAM battery
- Connected a Micro ATX PSU and made the required inverter for the power.
- I do not have a keyboard or mouse at this point but from what I have read this is not needed at this stage.

On connecting the power I get the red standby light. Pushing the power button and the light goes to green. If I insert a cleaning floppy into the drives it spins and ejects. System powers up but I get no video. My LCD monitor goes from "No Signal" with the power off to "Sleep Mode" when the power is on. I suspect that I need to do the 74ALS05 replacement but want to double check that this is appropriate for this model. I have buzzed through the v and h sync lines and it looks like it goes to the only 74ALS05 on board but I want to make certain. I have checked the (R,G,B,V Sync,H Sync) with an oscilloscope and I get signals for the R,G,B but when I test the H & V Sync it just produces a flat line.

regards

Richard