This cpu is still around in a dip package Hitachi HD68HC000CP12 i dont know if it would help

Tom

I just had a similar experience with a ste trying to recover data from a protar drive wirh my ultsrsan. I replaced the cpu with a hc type. And checked the current draw with my bench psu units it worked perfect put the old psu back on and random garbage again. I then but some of exxos ram in and prob...

Funny I ordered a lot of Atari st boards for parts cost me 50 euros. I got a almost perfect ste just a blown cap. And 1040stf working with a gotek drive in it and 1040stfm with a cracked case and I mean in lots of pieces and it also worked. I will parted the machine in the crack case put the ste bac...

Tom

Just make sure you have flux and solder that are leaded
Old solder can be hard to reflow it will have oxidized. Good cleaning

Tom

Yes a small glass like diode.

Tom

It does look like ic u66 has very little solder on some of the pins

Tom

That is a different question. But in canada they would kick you for not having ridge metal pipe. Corrosion would also be a problem leading to shorts. You maybe able to get away with armored cable as I have seen that just dropped in the ground safely.

Tom

I just remembered some crt history. The extra flyback were run off the crowbar transformer to but a charge on the tube to keep the x rays down until there was a horizontal signal. And it made them come on fast
Tom

Yes what rubber_jonnie said both pulling air out i should goto bed before 6am


Tom