Digipos Pro

This is a point-of-sale system which I bought as non-working in December 2022. It was listed as powering on, but displayed no output and output a number of beep error codes. The problem turned out to be relatively easy to fix - the included single 16MB SIMM module was either faulty or incompatible and after replacing it with two 32MB EDO SIMM's from my spares it powered on correctly.

Case Pictures

Internals

Motherboard

• Processor: IDT Winchip C6 200MHz
• Motherboard: DTV-07 Ali Aladdin M1521, Socket 7, 512KB Pipeline Burst cache, 2x 72pin EDO SIMM sockets, 3x ISA + 2x PCI (3 total max.)
• Video: Onboard Cirrus Logic GD-7548 (PCI)
• Storage: 3.5“ Floppy + 4.3GB Seagate IDE

• Processor: IDT Winchip C6 200MHz
• Motherboard: DTV-07 Ali Aladdin M1521, Socket 7, 512KB Pipeline Burst cache, 2x 72pin EDO SIMM sockets, 3x ISA + 2x PCI (3 total max.)
• Video: S3 Virge/DX 4MB (PCI)
• Network: Realtek RTL8139 10/100 + XT-IDE ROM
• Audio: Labtec ESS Audiodrive 1868F
• Storage: 3.5” bay mounted Compact Flash reader

As I said in the introduction, this was supplied with a single faulty 16MB SIMM and was fine after replacing it with two 32MB EDO modules.

After powering on the system for the first time I had ongoing issues with the keyboard not working, my KVM not detecting a keyboard, and, when the keyboard did work, the key repeat feature would not work. I also had trouble getting several types of PS/2 keyboard recognised (a basic Dell keyboard wouldn't even power up). Looking at the +5v line of the AT keyboard connector it was fine, and I tried multiple BIOS images without any improvement.

Eventually I started poking about near the AT connector on the motherboard and notice what appeared to be the typical PS/2 keyboard fuse:

Testing that for continuity I got really bizarre resistance readings, so I decided to bypass it - at that point the keyboard started to work properly. I'm not sure what failure mode the fuse was in, but it certainly hadn't 'failed open', which is what I would have expected. Anyway, bypassing it with a wire link proved that it was at fault, and my Dell keyboard came to life:

The system uses a 40x40x10mm fan over the custom PSU as well as a 50x50x10mm fan over the heatsink/heatpipe, both of which were noisy. They were removed and replaced with much bigger, slower spinning items.

No standard AT/ATX PSU in this thing - it was entirely bespoke, with a bespoke motherboard header. I decided to remove the 25+ year old PSU and replace it with a modern, solid state, cool-running PicoPSU instead:

dtv_07v4.pdf