Amiga 1200 losing time

[Captain Nemo]

My old Amiga 1200 is occasionally losing time. I replaced the RTC battery about a year ago so this shouldn't be the problem. When it first happened it lost a few hours, but most recently it went back to June 1996! As I say this has only happened twice in the last few weeks. The RTC is part of a Hawk RAM expansion board. I've left the Amiga switched off since Tuesday afternoon and will switch on again tomorrow morning (roughly 36 hours down time) to see if the problem happens again. I will probably change the battery just in case this is the cause. Could there be anything else causing this problem?
 
Thanks.
 
Nemo

[kedawa]

Aliens?
That's all I got.

[Drummerboy]

My old Amiga 1200 is occasionally losing time. I replaced the RTC battery about a year ago so this shouldn't be the problem. When it first happened it lost a few hours, but most recently it went back to June 1996! As I say this has only happened twice in the last few weeks. The RTC is part of a Hawk RAM expansion board. I've left the Amiga switched off since Tuesday afternoon and will switch on again tomorrow morning (roughly 36 hours down time) to see if the problem happens again. I will probably change the battery just in case this is the cause. Could there be anything else causing this problem?
 
Thanks.
 
Nemo

Check if the Battery contacts are whether he is making good contact

[Captain Nemo]

Thanks, that could be it. I just powered it up after about 36 hours turned off and the time is correct. It's a strange one.
 
Nemo

[zipper]

Must be a contact problem or a crack in some solder joint.

[Captain Nemo]

It's certainly looking like that is possibly the problem. I'll see how it goes.
 
Thanks.
 
Nemo

[xPhilx]

Firstly, and if your still with us, I'd look into close encounters of the 4th kind as Kedawa suggestes above.  This can be a bugger with Amiga problems.

If all's well and your still here with us and in one piece I'd illiminate the battery, sounds like it could be on its way out.  If your still losing time the next step is to check contacts.

I've personally not had this problem in my 1200 but have had it in a couple of A2000s which turned out to be duff batteries.

Good luck and keep us updated.

[Captain Nemo]

Thanks for the replies.
 
Had the A1200 powered down for three and a half days then powered up and the clock has reset itself to 01.54, 20 June 1996, which is the date the Workbench partition was written to disk.
 
I'll buy a new battery today and see if that cures the problem. The current battery has only been in there about a year though and I'm told they should last about two years (CR2032 type battery). I suppose it could be a duff one.
 
Nemo

[amiga92570]

Maybe its that Y2K thingy.

[Ilwrath]

Being that the machine lost the time while it was off for several days, but not when it was off for a short amount of time, I'm guessing it is just the battery.

Although, I do seem to remember having a bad version of 'c:setclock' that would screw up my A1200's clock.  XD

[Captain Nemo]

I've just replaced the battery with a new one. I checked the battery contacts and they appear to be good. I'll keep you posted.
 
EDIT: I measured the offload voltage of the old battery with a multimeter and it showed 2.96v. I understand that a fresh battery should be around 3.2v.
 
Nemo

[Captain Nemo]

Looks like it was a defective battery. Had the A1200 switch off for three and a half days then powered up and the time is still correct with the new battery installed.
 
Thanks for your help on this issue.
 
Nemo

[Zac67]

EDIT: I measured the offload voltage of the old battery with a multimeter and it showed 2.96v. I understand that a fresh battery should be around 3.2v.

Don't forget the diode's (you've got one in there, haven't you?) voltage drop - depends on where you measure, of course.