1.4 model FRAG 99% of the time, occasionally boots

Hello, I have a bit of a weird one here. I have a 1.4 model which I acquired as "untested" which was probably a lie given it was opened and mostly disconnected inside with missing screws. It doesn't look like any components have been pulled off the board. The system has the typical 3 attempts at boot and then flashes red and green 50%.

After testing it myself and discovering the FRAG, I decided to pull the clock cap and do a bit of a cleanup to see if there was any change, but no dice. I had mostly written it off until I needed a DVD drive and thought I'd try powering it on for laughs, and to my surprise it booted without DVD/HDD connected, no FRAG.

After connecting up a DVD and the HDD that came with it, the system continued to FRAG, so I thought if it turned on once, there's a chance it would do it again. Sure enough after a bit of trying it booted. Stupid me didn't have the controller USB ports plugged in, so I had to run the gauntlet again and after about 10 minutes it powered on. I Immediately ran XCAT.

I guess my question is, has anyone run into this behaviour before or any possibly solutions/things to try?

Things I've done so far

• Pulled clock cap, board looks mostly clean and had a visible small circle of gel around the cap. Killed it with IPA
• Tried a different PSU from a known working 1.4 system
• Visually inspected caps, no bulging anywhere and no crusty bits
• Dumped the EEPROM which seems to work when in FRAG via the LPC, not sure if useful since the HDD seems ok
• Frowned in the general direction of the console

Any help or insight from people who have dealt with FRAG before would be greatly appreciated!