Try tightening all the screws on all the boards. K9STH swears by this simple cure. I’ve used it on my TS120S myself and it really does seem to work.
I actually took a Q tip and some tarnX cleaner to the parts of the boards where they make contact under the screw.
Cleaning the contacts of the relays with tarnX didn’t seem to help much I managed to get a small piece of jewelers cloth for that job but I‘m told a dollar bill is just as good.
My rig is working fine for the last year or so. I might have to do this all again some day but it is simple enough that I feel I will be able to do it again without to much problem.
The fan on the back of my 120 rarely runs. When I was messing around trying to make PSK work it did start running at least once. It is very quiet and you have to look to see if it is going or not.
Any tool is a weapon if you hold it right.
“The only difference between stupidity and genius is that genius has its limits.” A. Einstein