• Please review our updated Terms and Rules here

Amstrad PPC512 CMOS Battery replacement

Shoka

New Member
Joined
Apr 29, 2006
Messages
6
Greetings,

Just acquired a PPC512 for a reasonable price. It's in pretty good nick condisdering, both disk drives work fine, screen looks good (or as good as it ever did), only problem is it complains that the internal battery is dead, and asks to re enter the date and time on each boot if it's disconnected from the mains.

Could anyone be so kind as to point me in the direction I'd need to look to find the CMOS battery in this? Considering in every other respect it seems to work fine, I don't want to do any unnecessary disassembly on it, if I could just go straight to this battery, that'd be the most desirable option.

Thanks very much.
 
It doesn't have a separate CMOS battery; the clock runs off the same ten C-cells that it uses for power when the mains isn't connected.
 
Ah I see, thank you.

So, seeing as the power switch on it is either battery or mains, when you've got these batteries installed, do you presumably just pull the mains to switch it off when it's on mains? Sounds a silly question I suppose.
 
I would assume so. Switching it off using the power switch would turn it off. In laptops, the battery keeps it running when external power is lost. So, when you unplug it, with the switch still on, it should stay running. Unless the battery doesn't hold a charge anymore.
 
So, when you unplug it, with the switch still on, it should stay running. Unless the battery doesn't hold a charge anymore.

Let me explain: The power switch on the PPC has two positions:

BATT. OFF
EXT. ON

and

BATT. ON
EXT. OFF

So if you have the mains plugged in, switching the switch with batteries installed would switch the power source to the batteries, you see what I mean?

What I'd guess is you just switch to the batteries unplug the mains, then switch back to switch off.
 
Oh. Does it turn on when the switch is set to Batt. On, Ext. Off, and it is unplugged from the "mains?" Unplug it first before switching it to battery mode.

And have you checked if it can remember its CMOS settings for more than 30 minutes after turning it off?
 
Does it turn on when the switch is set to Batt. On, Ext. Off, and it is unplugged from the "mains?"

It does indeed. Out of curiosity, I tried it while it was still on mains, and while plugged in, the switch does nothing. It must have the type of switch that connects the other setting before disconnecting the first. Not even a blip when you switch between power sources.

I'll just go down now and try it now it's been off for a while. At least two and a half hours. That should be a decent enough test.

...

Yeah, works great. Even tells you what time and date it was last powered on.

So yeah, definitely is the user installed cells that provide the clock memory. Logical, I guess. It's just the power switch arrangement I find odd. It'd make more sense to have perhaps a middle 'off' setting.

Just in case anyone may be interested, here is the power button arrangement. clicky clicky

So left like it is in that picture, if I were to plug the external mains supply in, it'd just power straight up.
 
Only one problem I could see with the middle "Off" setting is when the user wants to switch it from the external power setting to the battery setting. They would have to turn it off first, loose their work, turn it back on, and resume work. With the current configuration, that doesn't happen.

It seems that the battery is in working order. And from what you said, it also retains the CMOS settings.
 
Yeah, very true. Never considered that. Yes, all seems well with that machine now. Not bad considering it was sold me with a possibly broken screen and untested. My theory that the screen was disabled, based on a few things I saw on the sale for it turned out to bear fruit. Sometimes it's worth a gamble it would seem.

Thanks very much for all your help, everybody.
 
Back
Top