Reinstalling Win10 on corrupt Dell Inspiron 3580 Laptop CMOS problem Power Connector Replacement

[darknkreepy3#]

So a friend and client had a messed up Dell Inspiron Laptop, the 3580. No heavy damage, but missing screws she "put back in" and then when I took the laptop apart, multi-meter tested the power supply (ok) I could only guess the power supply port was damaged and the pin inside the official dell power supply.

I saw liquid damage on the CR2032 watch battery for the bios and the owner said she kept pushing the laptop against a wall for the "wifi signal" but she meant power supply port was "loose". She 100% damaged this thing and like most people was confused and wouldn't take responsibility for the damage "I don't know".

So, I replaced the power port cable for $8.35 on amazon. Still no luck. Took out the cr2032 batter, cleaned it and put it back in, made sure the power was unplugged from the laptop, and then removed the battery connection for the internal laptop larger battery. Power plug back in. Nothing, no light. Then... removing the cr2032 and putting it back in 30 seconds later I got 3 amber blinking lights, then another time, almost a screen signal, did it all again and voila. DELL logo, with nothing.

She was updating to Win11 while this was happening and that screwed it up even more. The settings in bios were all messed up as well. So here's the nugget of knowledge. I had a win10 21H2 image 07-2022 and I put it on a USB key with GPT and it wouldn't load with UEFI and proper settings, security stuff off in bios (PTT etc). Not even F12 could find the usb key. So, I made it boot as UEFI boot again... but I used rufus and made the USB with MBR as the format choice for the windows os installer, and then guess what...

Turning on the laptop, pressing F12 for boot options, in there was now the proper PMAP usb bootable win10 21h2 07-2022 image. One thing I did notice that was weird, just like a half working GPT version, the MBR had a scrambled screen at first, then I pressed the space bar and it went from the windows LOGO to an install screen, CUSTOM install into the 3rd 9xx~ gb partition that WIN11 upgrade still kept and there you go.

Scrambled CMOS?
I did update the BIOS by dropping it into a HIREN'S BOOT CD USB I made and then it ran with F12 for that, in legacy mode not uefi.
A messed up version of the win10iso? No, probably just a crappy scramble in the cmos.
But I got it to work and am sharing some ideas with you.