HP41 Auto off in 10 secs

[Mark Perlick]

I have several HP41's, both CV and CX. One CV has a strange problem. When I turn it on, it will auto-off in 10 seconds instead of the normal 10 minutes. If I "XEQ ON" it stays on continuously. Any one seen this before?

[Vieira, Luiz C. (Brazil)]

Hi;

I have one with the same problem. Besides the fact it's a lot less power consuming, it's something tricky.

The LCD driver controlls the auto-off. I traded the LCD assy with another 41CV (fullnut) with corroded keyboard and now it works great. I saved the LCD, because it's working alright except for this.

Hope this helps.

[Erik Wahlin]

I saw this problem once when I had a bad connection at the main cpu board.

[Vieira, Luiz C. (Brazil)]

Hi;

that's new info! I was not aware of this possibility.

Thank you, Erik!

[David Smith]

If I remember right there is a capacitor on the CPU board that connects to a pin on the HP41 display module. The cap determines the time out period. A bad connection between the CPU board and the display will cause the problem. Also (but not as likely) a bad cap. The HP41 service manual is on the HPMUSEUM CDROM set.

[Gina D]

On wich CD so i can print this manual?

[David Smith]

I'm not sure which CD it is. I beleive it is labeled "service manuals" or some such. Also has the HP97 service manual which can also be a help with the HP67 and the woodstock machines.