HP 67 and 97 odd behavior- HELP

[Fouad M. Kaadou]

Hello,

I have a problem with both my hp67 and hp97 both bought off auction sites. They both sometimes stop responding and when I press certain* buttons (not all have this problem) one of the numeric LEDs shuts off and turns back on when unpressed. The buttons always correspond to the same LED. Does this mean that both have fried circuits?

*On the hp67 only the last column (E, SST, h, CLX, 9, 6, 3, R/S)

*On the hp97 only the right set of buttons.

Help

-Fouad

[Katie Wasserman]

The keys on the 67 correspond to all the keys on the one column scan line. If the problem is intermittent you likely have a poor contact going to the keyboard on that line. Open up the calculator and clean the contacts to the keyboard.

On the 97, is the problem also intermittent and are all keys on the right half of the keyboard problematic?

Edited: 22 Nov 2011, 4:42 p.m.

[Fouad M. Kaadou]

Hello Katie,

Yes all the keys on the right hand side of the hp97 have this issue.

I will clean the keys on the hp67 and tell you what happens.

Thanks,

-Fouad

[Katie Wasserman]

Don't clean the keys on the 67, just the contacts between the keyboard and the main board.

On the 97, the only thing that distinguishes the right half of the keyboard form the left half is the contact sheet sandwich. It must be that the right half sandwich is misaligned. You need to take the keyboard apart and check the alignment. This is actually pretty easy to do, no keys need to be remove just unscrew the keyboard PCB from the keyboard and you should see the problem immediately.

[Fouad M. Kaadou]

Thanks Katie...

Cheers,

-Fouad