Faulty Register RS5 in HP-97

[Karl-Ludwig Butte]

Dear All,

I just executed the "Diagnostic Program" from the standard pac on my HP-97 and it showed error code 15, meaning that RS5 is defect. I further investigated and found out, that storing a value in Reg 5, f P<->S, f P<->S, RCL 5 shows either 0 or sometimes -0,66 but never 5 which was stored in the first place.

Does this mean that explicitely RS5 is defect or is another reason possible? Have any of you ever had a similar case and could it be repaired?

Any hint will be very much appreciated.

Thank you very much in advance.

Best regards

Karl

[teenix]

It would appear that the part of the RAM chip (Probably in ROM 6) that stores/recalls RS5 is faulty.

You could also verify this by

Code:


15 [h] [ST I]
5 [STO] [i]
[RCL] [i]

The display should show 5.

cheers

Tony

[Karl-Ludwig Butte]

Hello Tony,

thank you very much for your reply. I entered the code sequence you described and got 5 as result just as you described.

I then repeated my original Test 5 STO 5, f P<->S, f P<->S, RCL 5 and received the correct result 5, too. It seems that the malfunction disappeared.

The I retested the diagnostic program from the standard pack again which passed without errors, too.

Everything works fine again. I don't know how and why but I'm not complaining ;-)

Thanks again.

Best regards

Karl