I picked up an Onkyo HT-R510 that when I plug it in and press the power button will turn on and then a couple of seconds later turn itself off. When it turns on you can hear the relay click and then immediately click again and shut the power to the system off. I spent about 5 hours today trying to troubleshoot it and I did make some progress that may not actually tell me anything. It's still not really working and I'm not quite sure where to go next.
Here's everything I've done so far.
The first thing I did was open it up and check for any burn marks exploded parts or blown caps, but I didn't find anything visibly/obviously wrong with anything in the system. I tried disconnecting the board with the speaker jacks and the source input boards just in case something in them was shorting causing the amp protection system to kick in. It did the same thing when they were disconnected. I left the inputs and outputs disconnected and decided to press the power button about 5 times to see if I could get enough power into the amp to see if any of the components were getting warm. I found one NPN transistor (d2061 NPN) that was getting hot to the touch. I checked it in circuit with my dmm and nothing seemed off about what I was reading so I desoldered it and stuck it into my component tester. It read as a working NPN. Since this is a multi channel receiver I tried turning it on with the d2061 removed to see if it would stay on and it was still shutting off immediately. I did the power cycling again and found that the transistors on a vertical daughter board of the amp circuit was getting hot on the portion that corresponded to the channel that had the heating up transistor in it (photo 2). My next idea was to leave the d2061 out and also pull that daughter board out and see if it would turn on without it installed and it finally stayed on for an extended period of time. I never left it on for more than about 5 minutes just incase it somehow was putting stress on some other components. I checked around and nothing was getting hot on the main amp circuit so I figured whatever was wrong with the amp circuit was on the daughter board. I put it back in, turned it on and off a few more times to warm up the transistors on the daughterboard and found a PNP transistor (A1024 PNP) that was getting hot. I pulled the daughter board again and desoldered the PNP to test it. It was testing as a working pnp as well. I reinstalled the d2061 into the main board and left the A1024 out of the daughter board and put everything back together enough to test it. It was still clicking on and off. I did the power cycling for heat thing again and the d2061 that was getting hot before was now fine and cool to the touch but a couple other of those and a couple other of the A1024's on the daughter board were starting to get hot. At this point I was getting a little frustrated with it and decided to just remove all the d2061 and A1024's from the amp circuit and test them and they all read as working with no faults.
After a few hours of doing all this I started looking at the logic boards chips and using the power cycling to try to see if anything was getting warm, but I couldn't find anything that was heating up. I checked some voltages and checked for shorts with my dmm and I couldn't find anything out of the ordinary on the logic side of things. Reluctantly I went back to the amp circuit and decided to have another look at everything on that side of things. At this point I thought I had an idea of what channel was causing the problems, how to make the system stay on for more than a second, and what types of voltages I should be expecting to see on some of the traces coming from the logic board. I got no where checking voltages because everything seemed like it was what it should be or the voltage would get lost in a diode or resistor. When this happened I'd take it out and check it only to find it was working fine so I'd put it back. I finally decided to take out the audio amps for the trouble channel and see if I could find anything wrong with them and see if the behavior of the amp changed any. The chips were A1962 and C5242. The amps didn't test as shorted when they were in circuit (and they never got warm during any of the power cycling) so I removed them and they still didn't test as shorted out of the circuit. For them I could only check them with my dmm since my component tester isn't able to test them, but they tested alright in diode mode with my dmm. I put all the components back in that I had removed except the amplifiers and turned it on again. Surprisingly the who system came to life and stayed on, again I didn't leave it on for more than about 5 minutes at a time just so I didn't damage anything. I thought I was in the clear until I felt the d2061 and the A1024 that corresponded with the amps I removed and both of them were just as warm or warmer than they were before, but none of the other transistors or amps were warm at all.
Currently this is where I left it alone for the night. I can't find anything else connected to these transistors that would be causing any of these issues, nothing is shorted to ground or any other power rails as far as I can tell from checking, and nothing else connected to the amps is shorted or testing bad. I'm at a loss for where to go next other than pulling every single component out of the circuit for this specific channel and testing it.
I know this was an info dump/long rant, but any and all help with this one would be appreciated. I'm not really sure where to go next with this one and I'd love to be able to get this one working again. Please let me know if anyone needs more info, more pictures, or datasheets for any of these components I've mentioned and thank you in advance for any help or advice.
Here's everything I've done so far.
The first thing I did was open it up and check for any burn marks exploded parts or blown caps, but I didn't find anything visibly/obviously wrong with anything in the system. I tried disconnecting the board with the speaker jacks and the source input boards just in case something in them was shorting causing the amp protection system to kick in. It did the same thing when they were disconnected. I left the inputs and outputs disconnected and decided to press the power button about 5 times to see if I could get enough power into the amp to see if any of the components were getting warm. I found one NPN transistor (d2061 NPN) that was getting hot to the touch. I checked it in circuit with my dmm and nothing seemed off about what I was reading so I desoldered it and stuck it into my component tester. It read as a working NPN. Since this is a multi channel receiver I tried turning it on with the d2061 removed to see if it would stay on and it was still shutting off immediately. I did the power cycling again and found that the transistors on a vertical daughter board of the amp circuit was getting hot on the portion that corresponded to the channel that had the heating up transistor in it (photo 2). My next idea was to leave the d2061 out and also pull that daughter board out and see if it would turn on without it installed and it finally stayed on for an extended period of time. I never left it on for more than about 5 minutes just incase it somehow was putting stress on some other components. I checked around and nothing was getting hot on the main amp circuit so I figured whatever was wrong with the amp circuit was on the daughter board. I put it back in, turned it on and off a few more times to warm up the transistors on the daughterboard and found a PNP transistor (A1024 PNP) that was getting hot. I pulled the daughter board again and desoldered the PNP to test it. It was testing as a working pnp as well. I reinstalled the d2061 into the main board and left the A1024 out of the daughter board and put everything back together enough to test it. It was still clicking on and off. I did the power cycling for heat thing again and the d2061 that was getting hot before was now fine and cool to the touch but a couple other of those and a couple other of the A1024's on the daughter board were starting to get hot. At this point I was getting a little frustrated with it and decided to just remove all the d2061 and A1024's from the amp circuit and test them and they all read as working with no faults.
After a few hours of doing all this I started looking at the logic boards chips and using the power cycling to try to see if anything was getting warm, but I couldn't find anything that was heating up. I checked some voltages and checked for shorts with my dmm and I couldn't find anything out of the ordinary on the logic side of things. Reluctantly I went back to the amp circuit and decided to have another look at everything on that side of things. At this point I thought I had an idea of what channel was causing the problems, how to make the system stay on for more than a second, and what types of voltages I should be expecting to see on some of the traces coming from the logic board. I got no where checking voltages because everything seemed like it was what it should be or the voltage would get lost in a diode or resistor. When this happened I'd take it out and check it only to find it was working fine so I'd put it back. I finally decided to take out the audio amps for the trouble channel and see if I could find anything wrong with them and see if the behavior of the amp changed any. The chips were A1962 and C5242. The amps didn't test as shorted when they were in circuit (and they never got warm during any of the power cycling) so I removed them and they still didn't test as shorted out of the circuit. For them I could only check them with my dmm since my component tester isn't able to test them, but they tested alright in diode mode with my dmm. I put all the components back in that I had removed except the amplifiers and turned it on again. Surprisingly the who system came to life and stayed on, again I didn't leave it on for more than about 5 minutes at a time just so I didn't damage anything. I thought I was in the clear until I felt the d2061 and the A1024 that corresponded with the amps I removed and both of them were just as warm or warmer than they were before, but none of the other transistors or amps were warm at all.
Currently this is where I left it alone for the night. I can't find anything else connected to these transistors that would be causing any of these issues, nothing is shorted to ground or any other power rails as far as I can tell from checking, and nothing else connected to the amps is shorted or testing bad. I'm at a loss for where to go next other than pulling every single component out of the circuit for this specific channel and testing it.
I know this was an info dump/long rant, but any and all help with this one would be appreciated. I'm not really sure where to go next with this one and I'd love to be able to get this one working again. Please let me know if anyone needs more info, more pictures, or datasheets for any of these components I've mentioned and thank you in advance for any help or advice.
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