I have this pioneer receiver, and according to the owner it intermittently is in and out of protection, otherwise works great. Anyone have any service literature on it or know of any common issues? Any advice would be welcome. Thanks
Probably a bad capacitor on the relay drive circuit.
if it is leaky, the circuit will stay in protect mode as it does when the reciever is first turned on.
if it is leaky, the circuit will stay in protect mode as it does when the reciever is first turned on.
I fixed an SX-1250 with the same fault last year, very similar to SX-1080.
It was the fault detection transistor on one of the power amp boards. Apparently they go leaky and trigger the protection for no good reason.
In your SX-1080 it is Q8 on the power amp board. Replace on both boards.
Original is 2SC869, I replaced them with 2SC2383.
It was the fault detection transistor on one of the power amp boards. Apparently they go leaky and trigger the protection for no good reason.
In your SX-1080 it is Q8 on the power amp board. Replace on both boards.
Original is 2SC869, I replaced them with 2SC2383.
Awesome, thanks for the info everyone, I will let you know what I find. EssB. when you say both boards will I find to identical power amps, one for each channel? Both using the same Parts locator designations, in other words two Q8's? Thanks
Yes, two powr amp boards and two Q8's.
Download that service manual from Vinylkid58's link, all will become clear .. eventaully!
Stocktrader200 is right to suspect bad electrolytic caps, even though they weren't the problem in my case.
One thing I did was disconnect the input from the protection board to localise the problem. Lift one end of R2 on the protection board. This will disable the overcurrent protection. If the fault now clears you'll know the problem is on one the power amp boards. Obviously this assumes there isn't a pre-existing real overcurrent or overvoltage (offset) problem with one of the power amp boards.
Download that service manual from Vinylkid58's link, all will become clear .. eventaully!
Stocktrader200 is right to suspect bad electrolytic caps, even though they weren't the problem in my case.
One thing I did was disconnect the input from the protection board to localise the problem. Lift one end of R2 on the protection board. This will disable the overcurrent protection. If the fault now clears you'll know the problem is on one the power amp boards. Obviously this assumes there isn't a pre-existing real overcurrent or overvoltage (offset) problem with one of the power amp boards.
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