HP 97 keyboard and more issue. Message #1 Posted by Ignazio Cara (Italy) on 18 Jan 2010, 9:54 a.m.
Hi guys, I need your help with a faulty Topcat HP-97, serial number 2008B65177 and mother board 97S like. When turned on, show 0.00 at the display, but it don't receive input by the keyboard in RUN mode, display light-off if any key was depressed in PRGM mode. If something is sent to the printer, show 'Error' and if a card is inserted in the reader appear incongruous data on the display and the driving motor not start.
I have tried to make some substitution among the electronic component taken from a working PCB. Step by step I have replaced the PIK 1820-1952 with a 1820-1723 ( is it compatible?), the ACT, the ROM 0, ROM 3 and ROM 6. Nothing to do, the calculator show always the same issue. I have tested the voltages Vss and Vgg. With a Vbat = 5,20 I have read the following values: Vss= + 6.00 and Vgg = - 11.61. Unfortunately I do not have an oscilloscope to check the SYNC, STR, RCD, Ô1 and Ô2. What other measures can I do with a multimeter to see what does not work? Thank in advance for your kindly help.
Edited: 18 Jan 2010, 9:55 a.m.
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