15C all functions work, but can't self test



#2

Hello,
I have an old HP 15c that I "inherited" from my uncle.
I'm trying to learn to use it and though it seems to execute all the functions properly, I cannot get it to do the self test or the keyboard test.
Instead of it going into test mode, it just turns on.

I know to hold down the x key, then press the "on" key, then let go of the x key, but no joy.

If anyone could help, I'd appreciate it.

Thank you.


#3

Hi,

maybe you mixed up the order of keys you have to press/release.

Before initiating the key sequence,

the calc has to be turned off.

Then:

1. Press and hold the 'x' key.

2. Press and *release* the 'ON' key.

3. Release the 'x' key.

Now the self test starts. After finishing, all segments are lit.

To return to normal mode, just press any key.

HTH

Raymond

Edited: 27 Aug 2004, 1:51 a.m.


#4

Yes, I'm sure I've done the sequence correctly,
In fact, I just put in a new set of Duracell batteries and tried the test again and it worked like a charm.
However, after getting it to work once, I now cannot get it to do it again!

Very frustrating :/

Thanks for your help though.


#5

Strange as it may sound, chances are you have a bad memory backup capacitor. Take the batteries out for 30 seconds, then put them back in. If you see PR ERROR, you have a bad capacitor. The capacitor should hold memory for at least five minutes so the thirty second test is usually enough to determine if it's a problem.

The value of the part is 22uf but it can be a standard radial leaded electrolytic or a surface mount tantalum - it depends on the age of the unit. I've never seen a tantalum fail, only the standard electrolytics.

#6

Found the problem. I was trying to make it do the test again immediately after a test. If I just let it sit for a minute, it can do the test again perfectly.


Possibly Related Threads…
Thread Author Replies Views Last Post
  emu48 - copy stack doesn't work (as expected) Thomas Radtke 2 2,021 11-11-2013, 02:19 PM
Last Post: Thomas Radtke
  [41CL] New Extra Functions version Monte Dalrymple 0 1,158 11-08-2013, 04:32 PM
Last Post: Monte Dalrymple
  Another Prime mystery - templates don't work anymore Michael de Estrada 2 1,405 11-02-2013, 11:34 AM
Last Post: Michael de Estrada
  HP Prime: in need of help with defining functions Alberto Candel 14 4,514 10-27-2013, 10:48 AM
Last Post: Alberto Candel
  HP-42S ESD self-test Yriarte 2 1,621 10-24-2013, 09:08 AM
Last Post: Yriarte
  Does the HP Prime software only work with Win 7/ 8 ? Michael de Estrada 3 1,711 10-12-2013, 02:52 PM
Last Post: John Ioannidis
  HP Prime spreadsheet functions SanS 0 1,946 10-04-2013, 04:23 AM
Last Post: SanS
  So I took a test with my Prime today ... kris223 12 3,666 09-25-2013, 07:19 PM
Last Post: kris223
  Stats functions on the HP34S Nicholas van Stigt 5 2,102 09-24-2013, 02:45 AM
Last Post: Nick_S
  Trig Functions Howard Owen 11 3,711 09-16-2013, 02:53 PM
Last Post: Fred Lusk

Forum Jump: