HP48SX LCD problem...


I picked up a completely non functional 48SX about 5 months ago hoping it would be the deteriorated contact foam under the keyboard flex ribbon. That is the foam which holds the the keyboard flex ribbon agains the logic PCA contacts.

It was, and after disassembly, a thorough cleaning of all contacts, including the LCD zebra connectors and a new foam inser the calculator worked perfectly. In fact I removed the connectors, cleaned them, ensured no dust on the PCA contacts or connectors, and then reassembled the calculator.

I put the calculator away without batteries for 4 months. Today I picked it up, installed the batteries (using this example for Chapter 13, Stretch Pioneers) and it now powers up with a vertical line to the extreme right of the display.

Today in an effort to remove the line I have:

1  disassembled and cleaned all contacts again!
2 reset with the reset under the foot.
3 reset with batteries out and reset under the foot.
3 tried all the diagnostics, it passes!

The line is still there! Any ideas?

I found the following link which may explain the problem, alas, not fixable:

HP48SX display problem

My serial number is 3147Sxxxxx

Cheers, Geoff

Edited: 15 Aug 2009, 5:20 p.m.


Since it was OK before you stored it, I would suggest taking a closer look at the contacts on the connector and the display under a magnifier.

Or the display becomes defective?


Have you tested it with another 48LCD?

I replaced a faulty LCD in a 48S with a 49G LCD and it works perfect. (Black LCD ).

I installed the faulty LCD in the 49G and it still is faulty.



Yes, have checked the connector strips, LCD panel and contact points on the logic PCA. I actually cleaned them again!

Every thing looks good.

The idea of swapping with a good LCD panel on the 49G never ocurred to me so thanks for that.

At the moment the location of the line is not affecting the display but it is annoying.

So I will look out for a bad 49G (as is not working) for a spare LCD replacement.

Cheers, Geoff


moment when I swaped 2 displays.


Possibly Related Threads…
Thread Author Replies Views Last Post
  Vintage HP 15C with bleeding LCD display Michael de Estrada 1 1,425 10-30-2013, 09:54 AM
Last Post: Jeff O.
  Missing LCD segments (48 SX) Matti Övermark 2 1,369 09-18-2013, 03:50 PM
Last Post: Matti Övermark
  HP 32s LCD part Trisnadi Sutrisno 2 1,418 08-27-2013, 02:12 PM
Last Post: Han
  hp 39gii lcd clear question giancarlo 7 2,699 08-18-2013, 07:30 AM
Last Post: Mic
  10BII LCD Repair K Gobeski 0 960 06-19-2013, 08:58 AM
Last Post: K Gobeski
  HP 75d: pale lcd characters Michael Fehlhammer 0 804 02-25-2013, 07:04 AM
Last Post: Michael Fehlhammer
  HP41 emulator for HP48sx - keyboard overlay needed Doug (NYC) 3 1,609 12-31-2012, 03:11 PM
Last Post: Allen
  HP 48GX with Black LCD - S/N ID Jeff Kearns 4 1,807 12-15-2012, 03:55 PM
Last Post: aurelio
  On calculator preservation (LCD darkening, pouches...) Marc Ferrer (France) 4 1,657 12-04-2012, 08:01 AM
Last Post: Marc Ferrer (France)
  Non HP very early LCD Calc? Ian Phillips 6 2,231 10-06-2012, 01:57 PM
Last Post: Frank Boehm (Germany)

Forum Jump: