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41CV won't turn on after reassembly. Did I kill it?
05-10-2019, 01:31 AM
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41CV won't turn on after reassembly. Did I kill it?
I opened up my 41CV to clean out the 6 key via the tiny holes in the PCB behind each button, using a tiny paint brush and isopropyl alcohol. No heat-stake removal was involved, just a removal of the bottom case, the CPU board, and the black insulating sheet that lays on the rear of the keyboard PCB. It was working perfectly fine before disassembly, as I had spent about an hour writing down some programs I had in memory before yanking out the batteries.

I tried the standard stuff: various combinations of backspace, enter, and on, shorting all the battery terminals inside the calculator using some foil, trying to get Beep to do anything in case it's just a screen problem, etc. The batteries are currently reading 1.2 V each, but the calculator seemed to be working fine at that voltage right up until I opened the case.

Three of the four screws are nice and snug, but the one nearest to the divide key spins freely when put all the way in, and doesn't feel very tight. I noticed a tiny hairline crack in this screw post, as well as the post in the upper left corner (when viewing from the bottom), even though that one tightens just fine. I have some epoxy curing in those two cracks right now. I put a screw into the posts first to slightly spread the cracks so the epoxy could flow inside more easily, then removed the screws. I'm going to let it cure until tomorrow evening to make sure it's good and solid before attempting to reassemble.

Is there anything else I should try doing to revive it before I go searching for a replacement?
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41CV won't turn on after reassembly. Did I kill it? - Dave Britten - 05-10-2019 01:31 AM



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