This unit presented with a broken cover down switch lever. It has other issues.
Power is good, clean with a scope. The turntable motor spins if I force it on by grounding the base on Q102 (motor run). The CPU clock (MN1421FPB) is running in the right range, strobe signals where they should be. I can't find a data sheet on that chip to show me any signals that put it in reset or some halt mode. The tonearm motor returns properly automatically if I rotate it out and turn the unit on.
I hate logic issues without enough clear documentation. I have the manual. Any pointers would be very helpful.
Thanks, Chris
Power is good, clean with a scope. The turntable motor spins if I force it on by grounding the base on Q102 (motor run). The CPU clock (MN1421FPB) is running in the right range, strobe signals where they should be. I can't find a data sheet on that chip to show me any signals that put it in reset or some halt mode. The tonearm motor returns properly automatically if I rotate it out and turn the unit on.
I hate logic issues without enough clear documentation. I have the manual. Any pointers would be very helpful.
Thanks, Chris
Hi, apologies in advance if you have already considered what I have to say. I'm making no assumptions (best starting point for troubleshooting).
Background: I have rebuilt and serviced about 10 Technics compact DD turntables (SL-5/SL-Q5/SL-Q6) and have never had a problem with the main PCB. I also have about a dozen of the motor units from these turntables that I have bought as parts (I repurpose them) and I have never found one with a faulty microprocessor.
Have you fixed the lid switch? The motor will not run if the lid switch is open.
Have you done the "measurements and adjustments" per the service manual? I always start with the calibration of the turntable as if any of the tonearm sensors are not calibrated correctly then strange things can happen.
Does the motor (when you force it to) run at the correct speed?
Cheers, Mike
Background: I have rebuilt and serviced about 10 Technics compact DD turntables (SL-5/SL-Q5/SL-Q6) and have never had a problem with the main PCB. I also have about a dozen of the motor units from these turntables that I have bought as parts (I repurpose them) and I have never found one with a faulty microprocessor.
Have you fixed the lid switch? The motor will not run if the lid switch is open.
Have you done the "measurements and adjustments" per the service manual? I always start with the calibration of the turntable as if any of the tonearm sensors are not calibrated correctly then strange things can happen.
Does the motor (when you force it to) run at the correct speed?
Cheers, Mike