My "all out" mod ended up looking like this:
https://www.digitalfaq.com/forum/vcr...tribution.html

You can see the temps with the fan are at least 15 degrees lower with the fan on, but that's probably not actually necessary, also adding heatsinks to the main chip would probably reduce temps another 5 or 10 degrees.

In general, I'd probably just recommend recapping the TBC card, getting rid of the distribution amplifier and powering the entire thing on 5V instead since the 12V is only needed for the distribution amp. I used a separate "Studer 900" ultra low noise power supply for mine, but that's also probably overkill since the original design uses linear regulators to drop the voltage to 3.3V for most of the card which are pretty low noise regulators anyway. Alternatively, just using a basic wall-wart-type power supply would be much lower noise than most switching power supplies.

I'd do a regular bypass mod using original input and output plugs and not adding any extra switches or fan for $300 if you're interested. I can add a heatsink to the main chip at no cost if you want. The original obviously never had one, so it's probably not needed now. The audio plugs would not be connected at all since the unit doesn't do anything with audio when the distribution amplifier isn't there.

All the distribution amplifier does is split the one video output (and the one audio input) into four outputs which can affect the signal and isn't as clean as using the direct output from the TBC card.

I only use genuine Panasonic, Nichicon, and Rubycon 105˚C caps sourced from Mouser.com to guarantee authenticity as well.

If for some reason the recapping/bypass mod doesn't work to get rid of the glitch, I'd refund everything but $100 to cover return shipping and for some of the time/parts spent doing all of that.

I think Diopterdoctor charges more like $500 for his recap and bypass mod, but I don't know that for sure. He may have some more advanced techniques if it's not the very common capacitor and distribution amp problem, but I think 90%+ of the time doing the bypass mod and recap gets it working as good or better than new.

PM/Direct Message me if interested.