41C Display "Memory@@@@@@"


Any suggestions about what's wrong?


This is a symptom of bad internal connection, usually due to broken screw posts or broken screw seats. Look at the very nice article about fixing a 41 at the article archive.



Renato pointed out a common procedure that, in most cases, work perfectly well.

But as you have a [MEMORY@@@@@@] display, intended to be a disguised [MEMORY LOST], I must warn about the possibility that you may also have cold soldering OR bad contact in some chips.

I have a fullnut 41C that does not work anylonger, and I surelly detected one ROM (ID 1LE908) that is faulty and, when installed in other calculators, shows the following problem:

- if you hold any of key you'll have a brief [CLX @ @ @] and [NULL @ ]
- if you use any key normally, it generates a [NONEXISTENT] message.

If you have the 1LA701 RAM as a fulty IC, [MEMORY LOST ] is displayed constantly, and you'll see a brief blinking (should see it in some twisted angles against reflected light), one for each second (1 Hz).

If yours is a halfnutt, nothing of what's written above applies.

I would like to help, if I kow how.


Luiz C. Vieira (Brazil)


I got this 41 from a friend because it wasn't working. Reportedly dropped. The display shows darkened areas around the edges of the LCD. I separated the halves of the case and noted that two screws were stripped. Upon reassembly the display shows different characters. Guess I need to fix the screw seats. The display can be activated by pressing keys other than POWER. Anybody know how to reposition the short piece of black plastic that dislodged when I separated the halves. It apparently applies pressure to some component on the inside when the halves are reassembled. I am not speaking of the trim that holds the halves together. This piece is two inches long and is on the side behind the display.



this small plastic piece is mounted in the top of the display and is intended to keep the LCD in place (the plastic piece itself feels a bit loose in place). There are two small "tabs" in one of the alignments. These tabs are intended to be in the outher side, say, you should see them after placing the piece.

I'd like to know if the darken areas around the edges are spot marks or sort of a frame. There are two types of HP41 construct as you can see below:

If my explanation is not good, let me know and I'll add an image so you can "see" it in place.

Best regards and success.

Luiz C. Vieira - Brazil


The 41 is a Fullnut. The darkened area is within the margin of the area where the digits appear. It looks like a damaged etch-a-sketch.


Yes, Luiz, I would like to see an image of the placement of the small plastic piece if it is not inconvenient. By the way, I sent a mag card to someone in Brazil a year or so ago. I wonder if it might have been you.


Hi, Kris;

try the image below:

The upper image is shows the plastic out of its position, ready to be rotated. The mid image shows an intermidiate point and the last one shows the piece on its final position. You may place it directly, without rotating. I built the images like this just for showing the final, actual position.

I hope this helps.

About the card, what sort of mag card? For the HP82143A? I remember I received a pack of mag cards, but from another contributor in here: I do not mention names without previous consent, but he knows I know who is he.

Maybe another of our fellow contributors was the fortunate guy.

Best regards.

Luiz C. Vieira - Brazil



in my previous post, where it's written:

what sort of mag card? For the HP82143A?
please read:
what sort of mag card? For the HP82104A?


Mag card was from my HP41CV supply. Party in Brazil had posted a request on the Classified board wanting one card for testing. Apparently didn't have any cards at all. Surely you would remember if this had been you.


Hi, Kris;

just to know if the image I added help you placing the structural piece. Need more advice?

Best regards.

Luiz C. Vieira - Brazil


Yes the image helped. Thanks very much.

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