Hp-28S Does not Turn On

[aj04062]

I recently cleaned my HP-28 taking care not to get too wet (used damp cloth etc).

Now when I install the batteries, all that I get is a slightly dimmed screen when I press on. No combination of keys that I have done so far has reset it.

An suggestions?

[Namir]

HP-50g?

[Frank Rottgardt]

The 50g as well as the 48 series are IMHO overwhelming with to many functions and menues. In college many mates had the 48SX while I prefered the 28s because of a more straight forward approach. Today I have both calculators, but still I am a lot faster on my 28s. But the lack of I/O is of course a problem.

[Dave Britten]

If the screen appears to get power and darken just slightly, but nothing is displayed, it may be a stuck key. I have a 32s that did the same thing, and was able to fix it.

Also, you've tried adjusting the contrast already, right? (Hold On, press + or -.)

[aj04062]

Tried to find stuck keys, can't find one.

Interestingly, On - or + DOES ALTER the contrast.

[Eric Smith]

That means that the processor is running correctly.

[Lincoln R.]

This will sound obvious, but make sure you put the batteries in right. I once had my 48g doing some very weird things, turned out I had reversed one of the batteries.

[aj04062]

I did and did not make that mistake.

[Bart (UK)]

Tried another set of batteries? (just because they came new out of a packet doesn't always mean they're good).

[aj04062]

I've tried several sets that work okay in my 41. I'll buy a new set and try them out.

[Bart (UK)]

I was more thinking a dead cell, but if they work OK in the 41 then there's probably some other reason for not working.