I searched through my communications with my tech when he was servicing my tt 101. Below are some pertinent quotes on the construction of the boards and how he went about fixing the table:
--There were no bad parts, just bad connections. I ended up resoldering all the feed thru eyelets, then flipping the board and removing the solder with a sucker, then resoldering them with much less solder. They all look pretty clean now. I know other companies that used the eyelet method had reliability problems. For some reason the solder cracks around the eyelets, probably related to different coefficients of thermal expansion.Hope it helps someone.
--Besides I took a lot of solder out of those eyelets. The issue is the eyelets are hollow so they don’t fill with solder. The hot air insides always bubbles the solder out. I put just a bit around the edges and then cleaned the flux with acetone.
--The PCB is two sided but without plated through holes. It looks like they put eyelets in and then solder on both sides. I found one that was open but by the time I pulled the PCB it was connecting. I resoldered it and now the 45 light comes on and that speed works. The 33 light never comes on so I think there is something wrong with that flip flop. It is made of all discrete transistors so it is really hard to figure out the logic flow.
--I’m always amazed when someone would design a product as complex as this, with a high price, and not spring for a plated thru board. It boggles the mind that they would have relied upon these eyelets which are labor intensive.