View Full Version : Z-248 post issue

November 11th, 2017, 05:43 PM
The first PC's that I used were Zenith Z-248's, so for years I wanted to get one. I have one and it's bone stock, with all Zenith boards installed (CPU board, MFM/floppy controller, 16-bit I/O, 16-bit memory, 8-bit serial/parallel board with breakout connector, and EGA board). I seem to recall this being a pretty standard board compliment, usually including a ST-225 hard disk.

The problem is that it doesn't seem to post at all. When powered up, the power LED on the front panel lights up, and the hard disk spins up and chirps. The HD activity LED doesn't light at all, there's no display, no access to the floppy drives, and no beeps from the speaker.

Any suggestions on where to begin checking this out?


November 11th, 2017, 08:35 PM
I rechecked the diagnostic LED's on the backplane and the I/O board tonight. The green backplane LED's light up as they should. The red I/O board LED's light up and then as it completes the diagnostics tests the CPU, ROM and RAM LED's go out. It seems to stop at the INT LED, leaving the INT, DSK and RDY LED's lit, never completing the diagnostics.

Besides the compliment of Zenith cards, it also has two Panasonic floppy drives and a Seagate ST-238R hard disk.