On ZX Spectrum +2A I have a tape deck was not working. Well actually it was working, but games were not loading as it seemed like the signal was missing. I will not go into details of disassembling ZX Spectrum +2 as it is pretty obvious. You get access to PCB of tape dec right away, to turn it around You have to unscrew couple of screws and that is all.
Without any deeper investigation after disassembly I decided to do couple of things right away:
But unfortunately and to my surprise, after this hassle nothing changed, still the same issue.
Then I noticed that something wrong with the powering on the board and it seems like the ground was missing.
After some further investigation, I have found that ground on the board was delivered by two bold that was holding the board, as the board was removed, there was no ground in one part of the board. And maybe due to oxidation or something like that ground initially was an issue. I have inserted back HA17324, added a jumper between grounds just to be sure and it seems problems were solved.
So here You go, if You have ZX Spectrum +2 tape working but no signal, check ground first.