Given the symptoms, I would guess you may have a motor fault, as in drawing too much current from said transistors. Off the top of my head I don't remember, what the typical current/ voltages should be. but the fact that this symptom repeats suggests the motors may be at fault. Could be something as stupid as the bearings needing to be cleaned and lubed. This is a function of miles and age. Always follow a process of elimination when troubleshooting this sort of stuff. Especially when the symptoms repeat themselves. GreggHi!
I have an issue with my Teac 90-16 that is driving me insane. The transistors driving the take up and supply motor keep dying. I today managed to rewind (without load) for a minute or less before yet another transistor died. Take up is even worse. Few seconds. Starting to feel a bit hopeless as I don't really find anything out of the ordinary. Collector measures 150 VDC and the control voltages feeding the bases of the transistors read 1-4 volts depending on mode. No shorts (except for the one emanating from a broken transistor), I just tried measuring the voltage feeding the bases to see if there was any spikes but couldn't find anything.
Anyone know how to fix this, or at least present a different perspective as I'm starting to feel blind?
Thanks View attachment 139846
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