Help to repair an HP91

[isanchez]

Hi Bernhard,
Thanks for your help. The 91 does not implement the card reader, only the printer. I am going to see which is the best option for the Act test...and the possible definitive solution.
I understand that using the second referenced Act you mention, it will manage the printer, but not with the first named Act.
By the way, I realised today that I had a PM from you from many weeks ago., when I was working in a 25....sorry, I noticed that very late. I have sent one PM to you today.
Steps could be:
1. Check input voltages
2. Check the ACT with any working ACT from an old 21/25...it will manage only the display.
3. The definitive ACT could come from a 29c, a late 25 or wait to your ACT progresses.:-)
4. If the Act is fine...then the ROM is the candidate...dead end....wait to your progresses :-)

Thank to all

Kind regards