HP-97 - More Tests - Still Not Working - Vintage Calculators

In the last video we looked at my 1979 HP-97 and 1990 Elektronika MC1103 vintage electronic calculators, both RPN (Reverse Polish Notation) calculators, and both were not working. This time round I'll concentrate on the HP, in the hopes I can get a bit closer to finding the fault, although, as I said in the previous video, I suspect the fault is a failed chip, if so, these are unobtainable, so the calculator will remain broken.

I'll show the tests I'd already performed using an oscilloscope along with a few fresh tests.

You can see the previous video here:
   • Epic Fail - HP 97  &  Elektronika MC 1103 ...  
...and you can see my other vintage calculators in this playlist:
   • Vintage Calculators - Mechanical and Early...  

Start 00:00
PCB Layout 00:18
Power on Reset 01:41
Sync, RCD, Strobe & Phi 02:43
Printer 04:03
Keyboard 04:49
IS & Data 06:04
Summary 06:48
Outro 07:02

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Outro Music
"As Yet Untitled"
by GrumpyTim (available to download from GrumpyTim's Bandcamp page)
https://grumpytim.bandcamp.com/

http://www.grumpytim.com