Post Reply 
HP-41C LCD display and driver
01-20-2020, 08:47 AM
Post: #1
HP-41C LCD display and driver
Hi All,
I've just got back into the world of HP calculators after a ~40 year absence! I've bought not one but three HP-41 calculators from TAS. The first CV needed a repair with Diego's excellent I/O module foil, and I cannibalized the other machines so that this one has original module covers and side covers. The #2 machine was an HP-41C, but now has the display and 41CV module from the third machine. With me so far?

The third machine is in a bit of a sorry state. It was a Zengrange Gunzen, so has the rubberized front panel and no access to the User, Prgm and Alpha keys - hence this one being cannibalized for parts for #2. However, it does work after a fashion. I've cleaned and dried the front panel / keyboard and this seems to be working OK. The big problem is that the upper segments of the display are ghostly. Slight pressure on the LCD restores the upper segment display, so I think some crud or corrosion has got into the display assembly.

Having transplanted displays, I'm confident in removing the display assembly again for examination, but I think I need to separate the LCD from the driver board to find out what's going on there. I've looked at page 3-4 of the service manual, but the pictures are not very distinct. I've also looked at photos at, which show that it can be done.

Does anyone here have experience in separating the LCD from the driver board to examine and clean it? I don't want to break the display assembly, but it's only half working at the moment.

HP-41C, HP-41CV, HP 50g, HP 35s, HP Jornada 420, DM41X β
Find all posts by this user
Quote this message in a reply
Post Reply 

Messages In This Thread
HP-41C LCD display and driver - Markeporter - 01-20-2020 08:47 AM

User(s) browsing this thread: 1 Guest(s)