Rev counter, MFA and temp light not working

Missed out on the cheap clocks on really don’t want to fork out £100 on a new pair

 

They didn't have a "DigiDash" sticker on them by any chance? With a late 90's date. I repaired a set a couple of weeks ago and they were a pain. "Digidash" had applied a red conformal coating "glue" to the entire board and it had stuck the PCB to the plastic carrier. They'd actually managed to get it on the pins which was causing a bad connection and it was awful to remove because it's set like rock. I'll put a picture up later for you to compare

 

I have just tested a spare Pcb I had lying around and it worked!!! However the Rev counter motor doesn’t work on that one. Nate that’s exactly what it is I can’t remove the pcb from the plastic housing. I was also reading through your very interesting thread on the issues you had. And I think I have the same issue with the transistor am I right in thinking it’s the far left one?

 

Yep, that a Digidash one :/ I'd love to get in contact with the guy to see how he repaired them and what the thinking with the coating was? Anyway, the first hard bit it getting it off the plastic, I heated it up gently and pried it up little by little. (No idea how much the heat helped)
Once you've got it off you need to try and remove the coating from the areas you're going to work in. I tried Alcohol, thinners, Nail Polish remover and Acetone non of which really have much effect. In the end, I kept applying acetone to let it soak in and scarped off what I could with a screwdriver. Once a fair amount was off I just got a big blob of solder and ran it over the components until they eventually came off. It's possible just tedious.

In the end I did replace the transistor but it didn't work! I had to go round and reflow most of the larger parts and I just replaced every other transistor too. The coating was also sprayed on and was all over the pin so I had to scrape that off too. Sorry I can't be much help but trying to accurately diagnose them is basically impossible because the coating hides any blown components or dry joints

 

I was able to very slowly pry the pcb out of the casing and replaced it with a old spare I had lying around and it worked!! Thanks for all your help