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 If you've enjoyed this video and you'd like to help support the channel, you can make a one off, no obligation donation, using the PayPal link below: https://www.paypal.com/paypalme/Grump... Outro Music "As Yet Untitled" by GrumpyTim (available to download from GrumpyTim's Bandcamp page) https://grumpytim.bandcamp.com/ http://www.grumpytim.com