HP-41CV power-on weirdness

[Adam Vaughn]

(11-08-2022 10:34 PM)rprosperi Wrote:  Internally, there are screw posts at both the top and bottom of the case (under the 4 rubber feet), and any one of the posts being broken can lead to the erratic behavior you're seeing.

Instead of trying to hold down the entire case at once, try these:

* Short the left- and right-most battery terminals
* Insert battery pack with new batteries (check voltage to be sure)
* Put the 41 onto a hard, flat surface (table)
* Press down on the side rails on both sides of the top row of keys, and while holding those try pressing [ON], etc. Don't press so hard as to deform the plastic or risk flipping it on it's side; firm, but not hard.
* Press down on the side rails on both sides of the 2nd row of keys from the bottom, and while holding those try pressing [ON], etc. Don't press so hard as to deform the plastic or risk flipping it on it's side; firm, but not hard.

Also, try [ON]+[<-] to cause ML, it may help.

If it will not power on, there is likely some internal damage...

Thanks for the reply. I tried your suggestions, with the following results:

• How long are you supposed to short the terminals? I tried holding a piece of foil between them for 30 seconds
• Checked the N cells, all four test good in a RadioShack battery tester
• No message appeared on the screen when the battery holder was re-inserted
• Held the side rails on both sides along the top row, pressed "ON" several times, no results
• Tried holding the side rails again at the second row, pressed "ON", no results. Did the same at each other row, again, nothing
  

Pressing another key definitely seems like a pre-requisite to getting this unit to power up. Unlike what I stated earlier, the "ALPHA" button is one of the buttons I can hold down as I press "ON" to get it to power up. Holding Backspace and pressing "ON" has yet to result in the "MEMORY LOST" message; I get "CLX" on the screen, followed by "NULL" if I hold it long enough. Sometimes I do get "DATA ERROR", though that might coincide with trying to power it up while holding down "PRGM", which has at least once resulted in a "PRIVATE" message along with the "PRGM" flag.
-Adam