Is this the Canon A1 Digital from about 1990? with tape load on the back rather than the side?
If so, at least the NTSC version included internal DSP for both record and playback, including 14.3 mHz sampling and full field memory for both Y and C. This would effectively perform a TBC functions for the tape being played; however, it was an "always on" function, not switched. (It also supported stereo sound recording and had a 1/2" CCD.)
Did the shop tell you which board is bad?
Might not apply to your case, however, my recollection is that the A1, L1, and L2 all used a similar tape transport mechanism that included slide switch in the mechanism that informed the electronics of the state/position of the transport, and if that switch became intermittent (e.g., dirty or corroded contacts) it might not allow the tape compartment to open or loading/unloading. (It happened to one of my camcorders in the 1990s.)
Also, I believer the unit may suffer from aging capacitors that impacted the EVF for sure, possibly other boards as well. (I no longer have my A1Digital.)
I see parts-only units offered for sale on ebay
. That might
provide a source for a board.