I've found one in the dumpster, belive me or not someone throw this piece of hardware away.
By a first visual impression it has the monitor plastic case damaged, I think it was due to the way the previous owner throw it away, also the keyboard is missing.
As usually happens with PC of this hera that haven't been boot for a while, the first boot was an explosion. So I decided to disassebly it and take a look inside.
It turns out one tantalum is gone. I've removed it and checked for other problems.
I've found another tantalum is in short. I've notice they are on the + and - 12v lines.
I've read on the Vintage Computer Federation forum (https://forum.vcfed.org/) that tantalum problem it's a common issue on the +-12v lines.
I've replaced all + and -12v caps, since they are not many. At first I've replaced it with 10uF ceramic, then I've moved to something next to the original one.
I've ended up replacing all the tantalum on the +12V, -12V and -5V line with new 10uF tantalum 16V caps. The one I've found has 2 pins, indeed the original one has 3, but this is not a problem since 2 of the three pins are shorted.
Once replaced I've boot it up... and it works!
But... the boot process ends up with an error. I've investigated further on this, that was an error referred to the missing keyabord.
I've found an XT type keyboard, and plug it.
And finally... it boots!
It's Microsoft MS-DOS 3.30 Italian version.
My PC has:
- Type 13 20mb WD25 HDD clicking on IBM 5160
- 5.25 floppy drive with it's driver board
- Video card
- A Serial port board
- A mysterious board
- Monochrome green phosphor CRT monitor
On the front there's the sticker of a shop that sold it, now of course it closed, it was called Master Audiovisivi Studio. Indeed the mystery board it's a AV board, AVL Genesis, a rare ISA board for AV production. Find more info here: https://www.stevenmichelsen.com/AVL/
Now it's time to repair the monitor case. By using Fusion 360 and design an upper plastic cover to hide the plastic damage and repairing the monitor case by soldering it's plastic with an soldering iron. The result it's pretty good.
After a couple of month I've try to boot it up again, and it stops working... better saying, it works after a few time I try to power it on. Hard drive it's not recognised and the boot process does not start.
Long story short, it was a PSU issue. It takes me a while to solve this, but finally was done and working again.
Long story short, it was a PSU issue. It takes me a while to solve this, but finally was done and working again.
Thanks to the people at https://forum.vcfed.org/ forum and eevblog forum https://www.eevblog.com/forum that helps me in this restoration!
My IBM vintage PC it's now good to go!
- read risk disclaimer
- excuse my bad english