JVC KDA 55 Tepe Deck - help needed

Hi all

I have had this tape deck for around 2 years and use it occasionally. Got it out recently. There was a burning smell and fusible resistor R544 had gone which connects to the motor that drives the take up reel and FF / RW. Replaced it and same thing happens again after a while - you can feel it getting warmer. R544 connects to 2 transistors X507 and X508 which I removed and tested - OK. Not sure where to go next.

Also, and bizarrely the right hand audio channel went as well. Not sure if directly connected. Tried to trace the signal path using service manual but struggling.

Any help would be appreciated as I want to rescue it.

Best Wishes