DECpc 425SE

Paul Koning paulkoning at
Wed Dec 4 19:08:24 CST 2019

> On Dec 4, 2019, at 7:53 PM, Antonio Carlini via cctalk <cctalk at> wrote:
> On 05/12/2019 00:36, Adrian Graham via cctalk wrote:
>>>> ...
>>>> The button cell looks very much like it is soldered in. It's approximately 12mm in diameter. I've read numerous warnings not to go to near a button cell with a soldering iron so I'm not really keen to do that, especially as I don't know for sure that it will fix the problem.
>>> I'm curious what the reason is for that warning.  After all, the thing was soldered in to begin with; it certainly won't mind the heat.  You'd want to make sure you don't short it out while doing it, of course; some insulating tape might help with that.
> There are plenty of warnings, e.g.:

Ok, but that's different, it talks about soldering directly to the cell.

>> Many years ago I removed the soldered coin cell from the control board of the Compaq 7000 series and replaced it with a 2032 coin cell holder, worked nicely so I can’t see why it wouldn’t work in this DECivetti monstrosity.
> Well I suppose removing it means unsoldering the two tabs from the motherboard rather than unsoldering the tabs from the cell, so maybe I'll give that a go. Then I could work out what the battery is, get a suitable holder and solder that in.
> It would, however, be much more useful if a manual turned up and I could just perform a system reset and get past the password that way!

Indeed.  But clearly a solder-tab coin cell is meant to be soldered :-) so unsoldering those solder joints has to be safe by definition (so long as you are reasonably prompt).  And if the cell is still good, you could then solder it right back in if you want.


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