Out of curiosity, what are the markings on your new RAM ICs?

Either way it sounds like you should stick with the old RAM IC's and
look for the problem elsewhere.

I would try replacing C14 next because it's an electrolytic capacitor.

Op do 18 mei 2023 om 14:54 schreef [ P J D ] <technogeist@...>:

I wish it was a measurement error, but it is not.

The original 0.1v 24 hour loss was with the old RAM. The new measurement
was using the new RAM.

Note that U13-14 were removed for the old RAM to read the same as the
new RAM with U13-14 in place.

Cheers

Paul


On 18/05/2023 13:48, Jacob V wrote:

Draining at 0.001V/s sounds like a measurement error. In your original
email you said you were losing 0.1V/24h. Why would this rate have gone
up by a factor 1000x?


Op do 18 mei 2023 om 13:44 schreef [ P J D ] <technogeist@...>:

Update:

Placing new RAM chips in causes the battery to drain at 0.001v per second!

With U13/14 removed and the old RAM chips placed back in, this also drains at the same 0.001v per second.

So, I'll assume U13-14 are the problem?

The new RAM chips were LP versions as Mondo recommended.

Any recommendations on U13-14 chip type?

Cheers

Paul


On 17/05/2023 15:13, Mondovermona wrote:

[Edited Message Follows]

Hi.

Have you finally checked the "good" chip on all three sockets?  The problem might arise from a latched CE signal or the like in two of the three sockets.

Although the CMOS memory chips are prone to show this hi-drain behavior when faulty, I would not let the CMOS controller chips U13 U14 off the hook.  Did you test with U13 U14 removed?

  In any case, its good to have some spare memory chips.

Look for the most recent issues of this type or, if you want to stick with vintage stuff, look after the "LP" versions, as there were two versions and only th LP version was meant for battery buffering.  The "normal" version would drain your battery even faster.

good luck
Mondo