Dantali0n  1d ago

This is the #HP #16702a logic analyzer restoration thread. It covers cleaning up pcbs against corrosive glue, replacing the harddrive and cleaning the device and case alltogether (ita extremely sticky)

A more cohesive story will eventually land on https://museum.dantalion.nl

Special thanks to @tubetime and @CuriousMarc for the inspiration over the years!

Show threadDantali0n  

So first up we pull out the #16716a turn it upside down and indeed see the protective covers, the foam and ahesive. This needs to go as the glue turns corrosive damaging the traces.

#corrosive #glue

Mar 22 at 6:44amWeb
Show threadDantali0n  1d ago

Luckily, our glue and foam became extremely dried out and britle, this is a big plus and combined with the minimal corrosion made removal trivial.

I used the plastic sleds as a scraper, being careful to test on a non-critical area hoping the plastic would be chosen to be to soft to damage silkscreen and traces.

This turned out extremely effective and I had most of the board clean in about 3 hours.

Show threadDantali0n  1d ago
There was a little oopsie with a 50 (51 with lead reistance probably) ohm resistor at one point and I only had this old school flux but we managed to put it back on.
Show threadDantali0n  1d ago

Then some thorough cue tip cleaning with isopropyl and we are good to go for this board hopefully. Worst corrosion is a couple of vias which have become untented, I consider myself very lucky.

Next up imaging the IDE harddrive and replacing it. It makes sounds that make me very nervous.

Show threadDantali0n  1d ago
Shit tits up, well have to do some digging but first a new harddrive before this one cooks it.
Show threadDantali0n  1d ago
To be frank, I think I actually recall this test failing prior to my repair.
Show threadDantali0n  23h ago

Turns out its not #IDE, its not even 40 pins, the analyzer uses a 3.5 inch 50-pin #SCSI connector.

Possible options, SCSI to USB converter with the necessary 3.5 inch 50-pin to high density 50 pin adapter. This option probably is not going to work very well.

Alternatively we buy a second hand PCI (not PCIe) SCSI adapter and use that on an old machine to make an image.

For this last solution I have high hopes. Currently looking at an Adaptec AHA-2940 or 2904

Show threadDantali0n  23h ago

To replace the drive we can either go fill tilt and convert 50-pin SCSI to IDE and IDE to Sata.

Or we can do something more reasonable and buy a SCSI to SD card board.

The SCSI to sdcard board is about 80 euro.

Show threadDantali0n  21h ago

Rather then some no name Aliexpress SCSI to sdcard converter I am going to go for the #ZuluSCSI blaster

The board looks neat and tidy and the firmware is open-source and configuration seems straightforward.

https://zuluscsi.com/

https://github.com/zuluscsi/zuluscsi-firmware

Show threadDantali0n  6h ago
An Adaptect AHA-2940U has been ordered and its on its way. It has #Linux driver support checked using https://linux-hardware.org/?view=search&name=2940u#list
Show threadLord egeltje 🦔 🇪🇺   6h ago
@dantalion #memories
Show threadDantali0n  5h ago
@egeltje these must have been expensive back in the day, you can get one for between 20/30 euro on marktplaats now. In case you need one for 'sentimental reasons'
Show threadpenguin4222h ago
@dantalion Is this the one that's a PARISC Unix box?
Show threadDantali0n  21h ago

@penguin42 I am unsure about the exact architecture of the CPU at this point, it runs at 150 MHz.

The system indeed does some form of HP Unix with X11 window server and a window manager to make it look and feel like windows 95.

Show threadpenguin4221h ago
@dantalion OK yeh I'm pretty sure it's the PA/RISC type then; I'm not sure if it's quite the same model, but we had one at the place I worked in ~2000. I'd expect it to be similar to an HP9000/7xx workstation.