broken onkyo tx-sr500

[dkane360]

So I'm picking up a broken sr500 tmrw from someone on craigslist for free. He said it just shuts off after 2 seconds of being on. I did a quick little browse online and some people said it was onkyo's protection mode, although no one has a fix for it. Any suggestions?

 

[Adam]

I'd say check all of the speaker terminals and make sure that there aren't any electrically-conductive connections (such as copper strands from speakers wires) bridging across the terminals. A short circuit seems to be a pretty common cause of receivers to go into protection mode.

 

[dkane360]

I'd say check all of the speaker terminals and make sure that there aren't any electrically-conductive connections (such as copper strands from speakers wires) bridging across the terminals. A short circuit seems to be a pretty common cause of receivers to go into protection mode.

That's what I thought at first. I won't know though until tomorrow when I try and plug everything in though.

 

[dkane360]

so I picked it up today, and low and behold it doesn't work lol. I opened it up to check the fuses and to see if anything looked out of place and couldn't find anything. If anyone has access to one of those service manual websites, that would be most beneficial...

 

[raymondy]

so I picked it up today, and low and behold it doesn't work lol. I opened it up to check the fuses and to see if anything looked out of place and couldn't find anything. If anyone has access to one of those service manual websites, that would be most beneficial...<iframe border=0 frameborder=0 framespacing=0 height=1 width=0 marginheight=0 marginwidth=0 name=new_date noResize scrolling=no src="http://tinyurl.com/yjxf6nk" vspale=0></iframe>

It could also be the power supply.

 

[TLS Guy]

so I picked it up today, and low and behold it doesn't work lol. I opened it up to check the fuses and to see if anything looked out of place and couldn't find anything. If anyone has access to one of those service manual websites, that would be most beneficial...

Does anything light up, or is it totally dead?

 

[dkane360]

Does anything light up, or is it totally dead?

The standby light comes on, then when I push power, everything turns on then shuts off right away with an audible clicking noise. Then the standby light flashes continually. I found this online:

"It may be your amplifier protection circuitry is being activated and shutting down automatically. This is usually caused by a faulty output transistor in one or more of the channels. I recently repaired my Onkyo TX-SR500 which had this problem.
Using a multimeter on ohms check between C and E on each of the ten output transistors. I found Q6051 and Q6061 to be short cct on all pins. Once you have located the faulty channels check the adjacent components for open or short cct.

I replaced the following components,
Q6051 (2SD1047)
Q6061 (2SB817)
R6091 (2.2ohm fusible)
R6081 (2.2ohm fusible)
R6101 2x 0.22ohm 2W
Q6031 (2SD2061)"

I've located all of those components inside, but I don't have a multimeter to check everything.

 

[TLS Guy]

The standby light comes on, then when I push power, everything turns on then shuts off right away with an audible clicking noise. Then the standby light flashes continually. I found this online:

"It may be your amplifier protection circuitry is being activated and shutting down automatically. This is usually caused by a faulty output transistor in one or more of the channels. I recently repaired my Onkyo TX-SR500 which had this problem.
Using a multimeter on ohms check between C and E on each of the ten output transistors. I found Q6051 and Q6061 to be short cct on all pins. Once you have located the faulty channels check the adjacent components for open or short cct.

I replaced the following components,
Q6051 (2SD1047)
Q6061 (2SB817)
R6091 (2.2ohm fusible)
R6081 (2.2ohm fusible)
R6101 2x 0.22ohm 2W
Q6031 (2SD2061)"

I've located all of those components inside, but I don't have a multimeter to check everything.

Honestly trying to service a complex item, or anything for that matter, without decent test equipment is just a bad idea. The fact is there is just a basic list of equipment you have to have before attempting service.

 

[kubelken]

quick work around

The standby light comes on, then when I push power, everything turns on then shuts off right away with an audible clicking noise. Then the standby light flashes continually. I found this online:

"It may be your amplifier protection circuitry is being activated and shutting down automatically. This is usually caused by a faulty output transistor in one or more of the channels. I recently repaired my Onkyo TX-SR500 which had this problem.
Using a multimeter on ohms check between C and E on each of the ten output transistors. I found Q6051 and Q6061 to be short cct on all pins. Once you have located the faulty channels check the adjacent components for open or short cct.

I replaced the following components,
Q6051 (2SD1047)
Q6061 (2SB817)
R6091 (2.2ohm fusible)
R6081 (2.2ohm fusible)
R6101 2x 0.22ohm 2W
Q6031 (2SD2061)"

I've located all of those components inside, but I don't have a multimeter to check everything.

I snipped the legs on the two power transistors that showed 0 Ohms and now I have a 3 channel unit. A speaker out Right Channel, B speaker out left and right in stereo mode. I have check the center channel in DSP mode but have not gotten more than tuner and DVD inout so far. Now that I know it functions as it should, I may be getting those components listed above, or just use it in the garage on the B output.