Post Reply 
HP-97 sudden death
12-26-2014, 07:25 PM
Post: #1
HP-97 sudden death
Hello everyone,

I have an HP-97 on which I fixed the card reader and printer and rebuilt the battery pack. For some time all worked fine, then one day after a charge cycle the machine did not respond anymore. Battery voltage is fine. I also checked the inverter, Vss and Vgg are OK (6.25 / -12.2 V). The calculator draws ~350 mA (~140 without the printer board) but there is no display and no visible digital activity (no Phi 1/2 clock, strobe or other signals). Reset to the ACT chip is OK.
Does anyone have any other ideas or do I have to assume the ACT is dead?
Thanks in advance!
--WD
Find all posts by this user
Quote this message in a reply
Post Reply 


Messages In This Thread
HP-97 sudden death - wine+dine - 12-26-2014 07:25 PM
RE: HP-97 sudden death - PANAMATIK - 12-27-2014, 12:52 AM
RE: HP-97 sudden death - Katie Wasserman - 12-27-2014, 01:29 AM
RE: HP-97 sudden death - wine+dine - 12-27-2014, 01:21 PM
RE: HP-97 sudden death - PANAMATIK - 12-27-2014, 07:25 PM
RE: HP-97 sudden death - wine+dine - 12-27-2014, 08:30 PM
RE: HP-97 sudden death - PANAMATIK - 12-27-2014, 09:55 PM



User(s) browsing this thread: 1 Guest(s)