Help Please 486 CMOS BATTERY STATE LOW,Won't Boot

[lordgalla]

Hi All; Ya I know 486,AMI Bios,Motherboard MB-1433/50 AEA -V V5.1 but this board ran nice,for all my better half's Dos games.
Sat for a while,now If I turn on passes memory test,beeps and display's CMOS BATTERY STATE LOW Press F1 to continue. Ok so I go into setup,set up as needed,drive,date,time,ect.F10 to save,reboot and the same thing comes up,everytime even after running,and a warm boot.
Ok,now the fun part: I have not changed anything,drives,video,ran fine a month ago..
There is no battery on this motherboard,there is a place where the battery would be,but no battery,holes there,but solder filled.
No jumpers,for CMOS clear,or normall,just solder filled holes.
The only thing on this board is a TH6887A 9321 Real Time Clock????Removable.Could this be the problem?Other people telling me no,should still be able to save CMOS even if the battery is dead?
Man is there anyway I can get around this,to boot this computer?? I know it's a 486 old board,but what fun would all this be without a challenge..
Can I maybe solder in a battery where the battery would have normally been?
What's got me is it keeps coming up onscreen CMOS BATTERY STATE LOW press F1 to continue,then goes into setup fine...I just can't save it,it reboots to the same message.........and no battery onboard,except that real time clock module....Any help.Info,Idea''s all Welcome,and Thanks in advance.

[Computer_Commando]

If I remember, a 486 has a battery like this:

[lordgalla]

nope sorry,no battery like that,and no connector pin's to hook it to..I went that route already.Thanks

All This board Has is  a TH-6887A 9321 Real Time Clock Module,That is supposed to have a Battery inside it??

Just want to know if there is a way around it,so I can boot this computer.Thanks

[Computer_Commando]

Solder pins into the holes and then connect a battery.  With power off, measure the voltage at at the pins.  Normally, should be either 3.0VDC or 4.5VDC.  Do some research on the TH6887A 9321 Real Time Clock to see what the battery voltage was when new, then get a battery to do the job.

This may not work, so you would have to replace the RTC with one of these:

Data Sheets:
http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2680
http://pdfserv.maxim-ic.com/en/ds/DS12885.pdf

[lordgalla]

ok,Thankyou.Will try to find a used one,if possible.
Thanks

[Computer_Commando]

RTC is less than $2 in qty.  Single unit price, maybe $5.

Find a junk motherboard and you might all the parts you need for free.

[lordgalla]

Found a new one online 10 bucks,worth it to me.was a decent board with the 50mhz DX2. It's on the way,Thanks for all your help.