It looks like I bricked my Kayak XU800 board. BIOS crisis recovery doesn't work either. There is no floppy activity. The BIOS chip is not socketed unfortunately, and I don't want to place an empty socket on the board with the risk of ruining the whole thing. So I figured I could hook up an empty socket in mirror-image. Test drive using a spare EEPROM:

Only a few pins left who are making bad or no contact... I slightly bent the contact points in the socket using a modified staple.

Sometimes you need to cut the bottom out for sockets to seat deep enough to make contact when on top of a chip.

BitWrangler wrote on Yesterday, 19:35:

Sometimes you need to cut the bottom out for sockets to seat deep enough to make contact when on top of a chip.

I see what you mean, but here's our brick:

Not many tall components, just a few low profile SMD caps or resistors but these are not obstructing.

I had mixed luck flashing chips while still in system, stuff like whole mobo trying to power off injected voltage etc, sometimes powering on and keeping it in reset helps

Well, I did something pretty dumb and impulse-bought a GPU for my retro PC, even though someone already offered to give me the same model I was looking for without paying £50 for it.
(I may be stupid)

Installing the 7600 GS has given my retro PC a good boost and saved the 5700LE for if I want to make a Pentium 3 PC with it one day, though I think I'm also running into some driver issues. (I just chose the most up-to-date drivers, which I know is not a good choice so I'll be looking into some better ones soonish)
Sonic Heroes (running at 640x480) does run better, but also noticeably runs way worse than I'd expect for a game that needs 16mb of VRAM and a Pentium 1, with more the rising platform gimmick elements in the first level causing a whole lot of lag.
Spore runs better but running in fullscreen constantly forces me out of it, and Peggle's hardware acceleration actually works better than software mode but the game looks like it was stretched slightly with nearest-neighbour filtering.
I've not yet tried any other games, although Discord Messanger does still work and Mypal does too and slightly better (but not by much)

There's definitely some kind of bottleneck in this computer, though I'm not actually 100% sure if it is drivers or if it's the CPU (3.06ghz Pentium 4 HT), or the motherboard (SiS chipset + no actual microcode for hyperthreading), or the USB 3.0 PCI card is saturating the PCI bus, or maybe Windows Vista is just too much for this thing after all and I should cut my losses & give up on it.
(or maybe I accidentally didn't put the molex connector in properly and it's throttling performance. I did try to put it in as far as I could but I didn't want to risk damaging the GPU board...)

(At the very least, I think hardware-wise this system is basically maxed out now for what the motherboard can feasibly support. there's definitely room to improve if I get a better motherboard, but I think that'd ruin the charm given how that's the only thing left in the build from the original computer.)

I had to print some government forms, which helpfully always have some fine print that isn't legible on the trusty dotmatrix printer. My Canon ip2700 is not working. It might just be a dead ink cartridge but it's hard to know with these things. Same deal with my retro inkjet, a Canon BJC-1000 that I got in 2000. But I had a 'photo' ink cartridge sitting around that was still sealed in the container, so I gave it a try. I was a bit surprised, it actually works...

VanillaFairy wrote on Yesterday, 20:50:

There's definitely some kind of bottleneck in this computer

SiS chipset

Mystery solved

CD-ROM repairs (sigh...)
Among all the retro repairs, individual points of failure and maintenance, CD-ROM drives are the ones that frustrate me the most. Even more than trace repair! Battery leakage causes tangible damage - you either succeed or you don’t with the repair. CD-ROM drives on the other hand, often don’t even properly fail - they rather get tired, don’t open or refuse to cooperate in countless other ways. And by the way, I never had a single CD-Drive that was fixed by cleaning the laser with IPA. Today I had a drive that would only reluctantly eject - but keeping the CD inside! (I have no idea how that is even possible - maybe the drive decided it was from now on a multi disk player???) I also had the glorious idea (after many years) to test my precious PLEXTOR burner only to find disks with heavy data corruption. At the end of such a day I always ponder the ZULU option but that’s not the same thing…(angry rant over)