I am not sure if this is the best forum for this question. If not, please direct me to the proper forum.
I have an Onkyo TX-SR607 MDD/MDC/MDF that will no longer power on. When I plug it in, the standby light comes on. When I hit the ON/STANDBY button, I hear a relay click and then 1 second later I hear another click and the standby light begins flashing. I believe this is the Onkyo Protect Mode.
The initial failure occurred when I was watching a movie through the receiver and heard a loud pop from the receiver. The standby light began flashing. After looking around I noticed that a speaker plug had been partially unplugged from the RIGHT-FRONT speaker. Possibly the plus shorted to the negative?
I have begun troubleshooting and repair of the problem. I obtained a TX-SR607 Service Manual (Onkyo TX-SR607 | Owners Manual, Service Manual, Schematics, Free Download | HiFi Engine). All fuses are intact. Thus far I have determined that R6071 (82 ohm) failed open, R6101 (.22 ohm) failed open, Q6051 (2SC5242) failed short, Q6061 (2SA1962) failed short, and Q6011 (2SC1740S) failed. I replaced all of these parts. I also replaced Q6031 and Q6041 due to suggestion on page 137 #5 in the TX-SR705 Onkyo service manual since it is a similar unit and the service manual seems more complete (Onkyo TX-SR705 Service Manual). I then verified R6081, R6091, R6021, R6071, and C6041 were all intact and the still the right value. Everything seems to be localized in the RIGHT-FRONT amplifier chain.
I adjusted all idling adjustment resistors counter-clockwise to go through the procedure to reset the idling current, but the receiver still clicks on and then 1 second later clicks off with the StandyBy light flashing, so there must be something else beyond the RIGHT-FRONT amp chain that has failed.
I am needing a little help in overcoming the final hurdle (hopefully) in the repair. Thanks for your help.
- Doug
I have an Onkyo TX-SR607 MDD/MDC/MDF that will no longer power on. When I plug it in, the standby light comes on. When I hit the ON/STANDBY button, I hear a relay click and then 1 second later I hear another click and the standby light begins flashing. I believe this is the Onkyo Protect Mode.
The initial failure occurred when I was watching a movie through the receiver and heard a loud pop from the receiver. The standby light began flashing. After looking around I noticed that a speaker plug had been partially unplugged from the RIGHT-FRONT speaker. Possibly the plus shorted to the negative?
I have begun troubleshooting and repair of the problem. I obtained a TX-SR607 Service Manual (Onkyo TX-SR607 | Owners Manual, Service Manual, Schematics, Free Download | HiFi Engine). All fuses are intact. Thus far I have determined that R6071 (82 ohm) failed open, R6101 (.22 ohm) failed open, Q6051 (2SC5242) failed short, Q6061 (2SA1962) failed short, and Q6011 (2SC1740S) failed. I replaced all of these parts. I also replaced Q6031 and Q6041 due to suggestion on page 137 #5 in the TX-SR705 Onkyo service manual since it is a similar unit and the service manual seems more complete (Onkyo TX-SR705 Service Manual). I then verified R6081, R6091, R6021, R6071, and C6041 were all intact and the still the right value. Everything seems to be localized in the RIGHT-FRONT amplifier chain.
I adjusted all idling adjustment resistors counter-clockwise to go through the procedure to reset the idling current, but the receiver still clicks on and then 1 second later clicks off with the StandyBy light flashing, so there must be something else beyond the RIGHT-FRONT amp chain that has failed.
I am needing a little help in overcoming the final hurdle (hopefully) in the repair. Thanks for your help.
- Doug
The protection circuitry and the complexity of discrete HT receiver amplifiers makes them difficult from the repairer and technicians point of view to analyse the problem and offer suggestions. It's not something that I would rush into myself and I'll wager that service organisations aren't offering discounted labour rates for either. Nonetheless, you might have to get the pros onto a problem like this, if you have routinely replaced a whole output stage to no benefit, as it seems. Worse, amplifiers have been known to snuff every transistor right back to the input stage in some designs without internal current limiting. This is again possible, now that sophisticated external protection circuits are relied on to provide a single point of action for all identified faults.
When there is a catastrophic failure like this, it suggests that the protection circuits failed, either causing or succumbing to the cause so it will require a lot more digging to get to the root of it. I can't get the server to properly load the manual, so I guess others who have tried to help are similarly affected ATM.
Doubtless, you already checked that speaker and lead etc. weren't shorting for some reason.
When there is a catastrophic failure like this, it suggests that the protection circuits failed, either causing or succumbing to the cause so it will require a lot more digging to get to the root of it. I can't get the server to properly load the manual, so I guess others who have tried to help are similarly affected ATM.
Doubtless, you already checked that speaker and lead etc. weren't shorting for some reason.
Thanks for the reply.
Yes I have everything disconnected from the receiver, so there are no *external* shorts.
As for the TX-SR607 manual, I had no issue this morning with the link. Maybe the server is now back online. However, you must register for a free account before it can be downloaded.
I am still holding out that there is just one or two more simple things to overcome to fix this issue. My cheapness and my sense that I *should* be able to find and fix this problem are keeping me from just buying a new receiver. I have fixed the obvious and now just need a little guidance as to where to look next.
I think my next step will likely be to try and determine which part of the protection circuitry is causing the unit to trip off. There is a VOLH line that comes from the output stages as well as IPROTECT which is over current protection. My issue is the receiver doesn't stay on long enough to really make any measurements.
- Doug
Yes I have everything disconnected from the receiver, so there are no *external* shorts.
As for the TX-SR607 manual, I had no issue this morning with the link. Maybe the server is now back online. However, you must register for a free account before it can be downloaded.
I am still holding out that there is just one or two more simple things to overcome to fix this issue. My cheapness and my sense that I *should* be able to find and fix this problem are keeping me from just buying a new receiver. I have fixed the obvious and now just need a little guidance as to where to look next.
I think my next step will likely be to try and determine which part of the protection circuitry is causing the unit to trip off. There is a VOLH line that comes from the output stages as well as IPROTECT which is over current protection. My issue is the receiver doesn't stay on long enough to really make any measurements.
- Doug
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