Blue PRAM Battery Leaked! Radius 81/110 victim and assorted questions . . .

Trash80toHP_Mini

Trash80toHP_Mini

NIGHT STALKER
68040
. . . at least I think I pulled out one of the Naked Blue Cells I bought new in the 20Kteens? Gotta find the baggie, definitely wasn't MAXELL anyway.

At any rate, if you have the plain Blue 1/3AA cells, pull 'em! Never seen one of these fail before. Been trying to get at every machine to make sure no cells remain in any of them. I'll install them for playtime only.

Which brings up the question of the day; who makes/sells the best button battery holder/replacement thingie for the stationary setups?

edit: https://68kmla.org/bb/threads/radius-81-100-yet-another-battery-acid-victim.51438/post-580071
 
Another Question: Are all Macintosh II PRAM Battery pairs Axials that are soldered to the logic board?

I've got a first release Macintosh II.0 that I haven't even tested yet. It pre-dates the NuChip ASIC Macintosh II.1. So wondering if this is just my problem or everyone with a Macintosh II has gone through it?

How are they usually replaced? Seems like the perfect victim for a soldered down Button Cell mod? Is it safe to test it with those suckers still in there?
 
Trash80toHP_Mini said:
Another Question: Are all Macintosh II PRAM Battery pairs Axials that are soldered to the logic board?
Click to expand...
Some are soldered straight to the board, some have a funny little daughter card thing that Apple started fitting to later IIxes and retrofitting to older ones and Mac IIs.

PS never consider any battery to be leak proof.

Trash80toHP_Mini said:
How are they usually replaced? Seems like the perfect victim for a soldered down Button Cell mod? Is it safe to test it with those suckers still in there?
Click to expand...
I got a two battery cell switched coin cell holder on flying leads, and modified it to take a wire from the middle of the two batteries, then wired it into my IIx and velcro'd it down to stop it rattling.
 
Thanks, got pics? I have an early rev of a button cell battery adapter, but the cells rattle about. I'll likely make a custom PCB with button cell clips to keep things cool as can be.
______________________________________________

This Macintosh II.0 is just getting better and better the more I check it out! Almost like my (unbeknownst to me what it meant) oddly branded "D" Drexel 128K/Plus/Performer upgraded treasure.

First off, it's near immaculate inside and out, almost no dust collected inside! Feets look extremely low mileage.
37 year old caps in there with zero signs of leakage!
The only thing missing is the HDD mounting tray.
MINT Toby Card . . .

. . . and when I removed the drive shelf, I found this puppy inside!

MacSprint II Cache Card - NOT FOR RESALE.JPG

MacSprint II 32K cache card accelerator! NOT FOR RESALE? I have to wonder if this was a test machine at Orchid and shelved when the NuChip Macintosh II.1 version was released? I hate it when things that aren't are claimed to be prototypes. Might could be "factory installed" upgrade thing, hence the NFS sticker, but no ROM revision stickers?

But it might just be an early revision that Orchid didn't bother to pull when the machine went into storage? Wondering if the ROMs are socketed on production boards? Very strange that they aren't socketed on this board? Dunno about the guesswork on any of that, but this thing sure is purty!

Is it safe to power it up to test? Thinking it won't boot due to dead batteries, but if it does, might a cap explode as some do in Duos?

edit: ROM is socketed on the Macsprint II JRL found on what appears to be a production board. NFS sticker replaced with serial no. sticker, but again, no Revision Sticker on the ROMs. At least the IC info is there. Can't tell if the ROMs on mine were scrubbed off with solvent on a Q-Tip or gone over with a magic marker. I've seen ICs with identifiers sanded off the top on a lot of boards from the day, but a ROM???

Production MacSprint II-0-c.jpg​


edit: this turned into quite the tangent, but it's my thread, LOL! I'll do a resto project thread at some point copying this drivel over.
 
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Yah! But I like the idea of using the button cell holders @Bolle put on his SE/30 Remix. A custom PCB soldered into the battery thruholes will be solid. No need for Velcro and look cool as all get out. ;)
 
you can solder cr2032 holders to the mainboard.
on most of my machines I have desoldered the 1/2 AA holders and replaced them with the buttoncells. now nobody will ever suffer a stupid leak! probably.
1777763748562.png
 
Don't think that'll work in my II, the batteries are too close, touching each other.

I never keep anything this nice around in any of my collections. A nice recap and a custom PCB with those holders and it'll be good to go. The wires/clipped leads of the 1/2AA cells are plenty strong enough to support the card and leave the logic board basically untouched.

Positive and negative ends align, are they wired in parallel for extra oomph? Mac II was the first ADB Power Key and backside power button enabled Mac. Might one be standby power for startup and the other for PRAM? Should look at the schematics I guess, it's a curious thing, probably why a II won't start up without 'em?
 
That is correct, re: the two batteries.

As I've mentioned in the past, I'm less worried about the black Varta 3 volt batteries than the later 3.6 volt batteries. The 3 volt versions are made of the same chemicals used in a coin cell battery. Lithium Manganese, instead of the Li-SOCl2 Lithium Thionyl Chloride compound used in the 3.6 volt batteries that cause the explosions when they die.
 
Trash80toHP_Mini said:
Yah! But I like the idea of using the button cell holders @Bolle put on his SE/30 Remix. A custom PCB soldered into the battery thruholes will be solid. No need for Velcro and look cool as all get out.
Click to expand...
Perfection is the enemy of progress. There is nothing stopping you use off the shelf holders until you get your custom adapters in 20 years time. At least the machine will be usable, and it doesn't require any actual modification to the computer.
 
volvo242gt said:
As I've mentioned in the past, I'm less worried about the black Varta 3 volt batteries than the later 3.6 volt batteries. The 3 volt versions are made of the same chemicals used in a coin cell battery. Lithium Manganese, instead of the Li-SOCl2 Lithium Thionyl Chloride compound used in the 3.6 volt batteries that cause the explosions when they die.
Click to expand...
They do seem to last longer, but we're past saying things like that because people misread it as "it is fine to leave 30 year old batteries in computers" and do.

Then we get posts like the first one in this thread.

I actually did buy a new axial 3.0v battery for my SE. Given the original lasted over 30 years and still held like 2.8v.

 
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