try these
https://archive.org/details/sp1363
although there is a another thread about the bios needing its own setup partition.
have you measured the bios battery voltage?
any bulging caps? (looks like there are not a lot of electrolytic caps)
looks like this is running on a AT power supply? any chance to try a different supply?
last thing id check after that is for loose pins with a microscope.

Thanks for your reply, is the bios battery the CMOS? My power supply is just a normal one but i will try a different one. Do you think I will need to replace the CMOS because if that is the reason I am not sure how to remove the battery, some people are saying its soldiered or something.

i think that correct that the battery for bios (cmos) is soldered onto the motherboard (from the images i saw).
if you have a multimeter and the voltage is close to 3v then its good and can save settings, otherwise it would need to be clipped/desoldered and replaced. But that would require tools.
it probably better trying to boot from one of those floppy images before messing with the battery.

I would try to boot from the floppy images but the floppy drive won't work because these errors (601-Diskette Controller Error & 611-Primary Floppy Port Address Assignment Conflict).

I probably won't be possible to use a flathead screwdriver or something and try lift the clip right?

The problem is that those metal pieces are soldered to the battery I would not try to force it too hard. If you ha be small sharp clippers you might be able to clip from one side.
But measure the voltage first if possible.
And if you did remove the battery you would need a soldering iron to remove the remaining bits and attach the new battery.

Ahh ok. I'm think I might take it to someone and get it replaced. Do you think this is a good replacement battery for it (https://www.pbtech.co.nz/product/BATPAN1054/P … thium-2032-Lith) But I might also buy a CMOS battery holder too and solder it there, it would make it easier to replace in the future.

Or what about this (https://www.jaycar.co.nz/cr2032-vc-3v-pcb-mou … attery/p/SB1762) could this be soldiered on. I don't think it is replaceable like the first link i sent but what do you think.

This isn't my photo but this is what the cmos battery looks like in mine (https://pbs.twimg.com/media/BsygSKFCEAAICtc.jpg)

yeah the right way would be to desolder the through holes. Not sure of the connection under the battery is a through hole based on the pic, but i think it is.
so i think you could replace it with that second link. But search for "vertical coin cell holder" and that will give you an idea of a 2032 holder so you never have to solder it again.

Alright thanks, just one more question about those floppy images for the bios. Do i just drag and drop the .img files to a blank floppy bc i have a external usb floppy drive or is there another way?

no that would only copy the image file itself onto the floppy. You need another program like winimage to write the image. (assuming your using windows)

Ok thanks a lot for your help Pickle

You don't need to replace the soldered battery on the MB, there is an external battery connector on that MB and a selector jumper for ext/int battery like many of these 90s compaqs. All you need to do is wire 4.5V battery on the external battery header and set the jumper. This is what id did with my Deskpro 466 XE some time back.

Really? Is that also for the Compaq Deskpro 5133? If i take a photo of my motherboard are you able to point out where the selector jumper is and where the battery header is?

(https://drive.google.com/file/d/1ndvVBwUv_gIS … iew?usp=sharing) This isn't my photo but are you able to see it here in this image

https://theretroweb.com/motherboards/s/compaq … 0-5166-prolinea

retroweb also documents it to the between the battery and backend of the motherboard.

Thanks for the link, looking at the motherboard picture on the retro web website, do you know where the external battery header is, I've found the jumpers. Also does this one look right? (https://www.pbtech.co.nz/product/SEVOEM0259/C … LE-Plug-for-Lap)

Just found the external battery connector, it looks like this: (first pin, gap, second pin, third pin).