[Solved] Computer won’t boot after replacing CMOS battery

About a month ago, my computer started to get this error message when I booted up, saying that the system clock hadn’t been synced. I ignored it for a while, but it happened every time I booted up. I looked it up, and it seemed the problem was that my CMOS battery was running low. I replaced it, and then I got the message that there was a problem booting, and I could either run startup repair, or just start Windows normally.

I ran the startup repair, and left it for a while, and came back to a blue screen. I turned it off (hard shut down), booted back up, and went for the “start Windows normally” option. It went through a few screens, but then just looped right back to the screen where you pick to do startup repair or not. As many times as I’d choose “start normally” it would just loop back.

I looked, and the CMOS battery I replaced it with was a Sony battery, and the original was “New Sun”. They’re the same voltage, but I thought I would just put the original battery back in. I did that, and now the computer won’t boot at all. It turns on, the power light comes on, and I can hear stuff moving like the fan and hard drive, but the monitor displays nothing, staying in power-saving mode, with an orange light instead of the normal blue.

Looking at some other posts both on this forum and others, other people had the same problem, and I tried some of the same solutions like unplugging the power supply and disconnecting the battery, and waiting a while for the power to cycle before putting the battery back in. Still nothing.

Can anyone tell me if I did something wrong, or just give me some solutions to this?