Sony TC-730 Reel to reel tape recorder

[RODALCO]

Hello forum members.

I have a problem with my Sony TC-730 Reel to reel tapercorder - amplifier machine.
It suddenly stopped while playing music, a small puff of smoke came out of the vents and that was it.
Today I tackled the machine and decided to have a look at it (about 3 months later).
Luckily I have a second Sony TC-730 which works fine.
I checked the mains fuse which was ok.
Had a look by taking the chassis out of the wooden casing and looked for the obvious. Nothing as such looks burned out or has a suspect smell.
No bulged capacitors.
The capstan motor works in both directions but no response from the reel motors or the solenoids.
The amplifier section works fine.
Unfortunately I can't find my manual which has an electrical schema in it.

Has anyone worked on one of these machines and knows the symptom ?

Many thanks for your reply.
Regards, Raymond

[vtech]

Having another working unit can help out better than a schematic.

Sounds like something gave up the ghost in the power supply or drive section such as a regulator/transistor/etc ..look closer around the power supply or follow back from capstan.

You can always set up the working unit as a reference unit on the side to do an A-B spot-check voltage test.

[RODALCO]

Thanks vtech for your reply,

it did cross my mind but at this stage I am not too keen to take the other unit apart.
Access to some parts is quite hard, even to do measurements on certain circuit boards.
I might end up with two broken units.

I'm hoping that someone with Sony experience has done repairs on these units or know about particular weak points.

I have heard that these are complex machines to work on.

Thanks, Raymond

[Guest]

Try paul stennings vintage tv and radio forum a lot of reel to reel people there

[RODALCO]

Thanks guest,

I did posted my question there too.
I'm checking the relays when time allowes as was suggested by one of the members.