My hp 41cv calculator was unstable

[Chiu Yiu Wai]

My hp41cv has been fixed the before , after that it worked properly , today I used it and does not turn off it , a few minutes later , it turn off automatically , and then the calculator stay in unstable status , sometime it can't detect the module , sometime it hang on , sometime can't turn on or turn off , I sure that it have not drop on floor or any liquid drop on it. I install a new set battery , it still unstable.

Do anyone can tell me why and how to fix it.

[Karl Schneider]

Hello, CYW --

Well, the basic steps are to try the "master clear" -- turning it on while holding down the backarrow key (<-) -- and if that fails, jumper together the battery terminals with battery out in order to discharge the internal capacitor. All of this is in the manual.

Is it a fullnut (rectangular display, made during or before 1985) or a halfnut (rounded-corner "masked" display, made during 1985 or later)? The fullnuts are more repairable.

-- KS

[Chiu Yiu Wai]

Thanks for your tips
It is fullnut version