No quick solution here.

- Try to find some default amibios passwords and try those, though I somehow doubt it will work.

- Read out the eprom and dump the file here, some good soul will likely be able to fix it and probably patch it up a bit more.

- Find a bios for a motherboard that has the same chipset as yours and try that one.

Good luck.

PS. If the password was stored in the cmos, it would've been gone already long time since the battery died.

The CMOS and RTC are in the 82c206 chip. You may have to jump the CMOS clear jumper overnight (rare) or remove the PSU connectors from board and jump 30 secs.
From the datasheet the battery backup goes to pin 15 PSRSTB#, "Power Supply Strobe: An active low input used to establish the condition of the control registers of the real-time clock when power is
applied to the device. In a PC/AT-based system, it should be tied to the battery back-up circuit.".
Maybe direct shorting pin 15 to ground with PSU off will clear everything ? Maybe someone smarter than me can figure that out....

Thank you, if i found similar bios chip set, is it worth trying it or will I still need to flash it to this motherboards bios?

Also, how do I get ext battery to work? I connected one to the 4 pins located by the old batt spot but doesnt work. It keeps saying low battery state on boot.

Is there a jumper that needs to set to choose between ext and int?

I am not sure what this motherboard is so dont have manual.

I would not change BIOS until some other things are figured out, the current one is most likely OK.
The J1 four pin header near old battery location is the external battery. Usually pin 1 is + and pin 4 is -, it needs 4.5v ( 3 x AAA or 3 x AA) to work.

thanks, yes thats what I connected, I have a 4.5V case with 3x1.5V abteries to 4 pin connector and either way I connect it, it still complains during post so wasnt sure if there is another jumper as some motherboards have jumper to select ext battery but without manual I cant figure out on this boarch which it might be.

https://i.postimg.cc/mBXR1s4w/IMG-2344.jpg
https://i.postimg.cc/tyz9y6m8/IMG-2345.jpg
https://i.postimg.cc/B4Q4vvrb/IMG-2346.jpg

any ideas anyone ? why isnt the external battery power recognised?

With 4 diodes in that area you may need a 6v external. Was rare but some boards did require it. If that does not fix it then you have a bad trace somewhere from Ext Bat to the 82c206 with the cmos/rtc.

Ok thank you for the suggestion, I'll try more voltage first and go from there. I'll report back once I give it a try.

I have ordered a 4x1.5V battery holder to test if higher voltage makes difference.

On another note, I ended up trying the googled generic AMIBIOS passwords and AMI was it ! I couldnt believe it but all good now, I got in and can make changes. Thank you.

Great !

Clearing CMOS must be done with the PC switched on, FYI.

Either while it's running, or... turn off, change jumper to 'clear', turn on for a few secs, turn off, change jumper back to normal.