The Museum of HP Calculators

HP Forum Archive 20

[ Return to Index | Top of Index ]

Hp-28S Does not Turn On
Message #1 Posted by aj04062 on 18 Sept 2011, 6:27 p.m.

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?

      
Re: Hp-28S Does not Turn On
Message #2 Posted by Namir on 18 Sept 2011, 7:13 p.m.,
in response to message #1 by aj04062

HP-50g?

            
Re: Hp-28S Does not Turn On
Message #3 Posted by Frank Rottgardt on 19 Sept 2011, 6:06 a.m.,
in response to message #2 by Namir

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.

      
Re: Hp-28S Does not Turn On
Message #4 Posted by Dave Britten on 18 Sept 2011, 8:56 p.m.,
in response to message #1 by aj04062

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 -.)

            
Re: Hp-28S Does not Turn On
Message #5 Posted by aj04062 on 18 Sept 2011, 9:38 p.m.,
in response to message #4 by Dave Britten

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

Interestingly, On - or + DOES ALTER the contrast.

                  
Re: Hp-28S Does not Turn On
Message #6 Posted by Eric Smith on 18 Sept 2011, 10:53 p.m.,
in response to message #5 by aj04062

That means that the processor is running correctly.

      
Re: Hp-28S Does not Turn On
Message #7 Posted by Lincoln R. on 18 Sept 2011, 10:02 p.m.,
in response to message #1 by aj04062

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.

            
Re: Hp-28S Does not Turn On
Message #8 Posted by aj04062 on 18 Sept 2011, 10:29 p.m.,
in response to message #7 by Lincoln R.

I did and did not make that mistake.

                  
Re: Hp-28S Does not Turn On
Message #9 Posted by Bart (UK) on 19 Sept 2011, 4:44 a.m.,
in response to message #8 by aj04062

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

                        
Re: Hp-28S Does not Turn On
Message #10 Posted by aj04062 on 19 Sept 2011, 7:02 a.m.,
in response to message #9 by Bart (UK)

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

                              
Re: Hp-28S Does not Turn On
Message #11 Posted by Bart (UK) on 19 Sept 2011, 8:15 a.m.,
in response to message #10 by aj04062

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.


[ Return to Index | Top of Index ]

Go back to the main exhibit hall