The information on this page also applies to M48Z18/M48Z08/M48Z35Y/M48T08
There’s nothing we love in our equipment more than a chip with a non-replaceable battery which eventually runs flat, and costs a fortune to replace, assuming the part is even still available.
Today’s culprit is from ST. In this case the part is still available and not as absurdly expensive as some of the rarer varieties but I’m not feeling patient enough to wait for a replacement.
Let’s go out to the workshop and mill this bugger open…
Can’t see anything yet. Time for another pass…
Ah there we go. A small coin cell battery. There were some sparks and smoke when the mill punctured it (which I was expecting).
Next job is to clear up and attach some wires in place of the old battery. Be careful about where the battery matter ends up as this stuff is poisonous.
I had a little bit of trouble persuading solder to take to the shell of the old battery, but it got there eventually. Inevitably the mill severed the negative terminal, so I had to dig into the potting compound to reveal enough of it to solder to.
And here’s the end result. The new battery is mounted in a Keystone 1061, but eh. Anything will do. I will never have to replace that chip again.
Posted in Repair / modification
Neat! I’m going to have to resort to these procedures in the near future whenever Analog Devices decided to stop manufacturing the Dallas clock chips!
Hi Matt,
I recently replaced a Lithium cell in a similar device: M48Z18.
Because this part was definitely un-unsolderable, I dismantled it completely and found some really handy solderpads…
Perhaps my repair log is helpful in this place:
https://www.wolfgangrobel.de/electronics/nvram.htm
Why do they do that? Why would chip manufacturers leave the consumer with a product that is destined for failure with intended, ultimate disposal because of? Sure, you resolved the issue, very few but some will….yet most will have no choice to toss the dead product. Is it to force consumers to buy the next best thing> Planned obsol..(how do i spell that word?). Planned obsolescence? Forcing a product life cycle?
Take Analog Devices for example…i would think higher of this company than to do such things, yet another commentor says otherwise.
Oh the amusing things some manufacturers get up to… sanding off chip IDs..making them illegible…is another…. that is one thing. Who wants your stuff copied right;) but the battery thing is another. Did they not think the consumer would us product past X time> Surely they know the battery life time..
Anyway. That is some fine dandy handy work…. and speaking of …another commentor Mr. Robel- that is a clean job done yourself…and boyoh your PCB gallery. I can almost smell the electricity flowing through them. Great gallery.