Intermitant loss of sound on right channel

If the channel is dead on headphones suspect a fault in that channel. The good news is that you have the good channel to compare it with. Since the channel parts are identical. You can start with a visual check. Looking at the good and compare with the bad. Any bad looking parts should be replaced. If you are experienced with electronics you can do tests on the channel. Otherwise it is off to a repair shop with it.

Jimbo

I am not sure about the LED fault lights....but I have a few troubleshooting angles to provide a start:

Try checking the power supply at the output devices and compare with the good (Left) channel.

The distortion you are hearing may be due to
low voltage.

This is a stereo amp, so you have a good (Left) channel to compare with. Use a multimeter to compare resistances (no power applied) or voltages (power on) at the components working back from the outputs of each channel. When you find a difference you have located the faulty area.
If you can get an oscilloscope it can also be used to trace the path back from the output of each amp. Good Luck Be careful!

Check first it is on all functions. If it is then it will be a power amp fault. As the unit has two channels both of which are identical to each other it's possible to check and compare each channel. So in your case the left hand channel parts are your guide to what is right. Compare first visually the two channels. If something looks burnt or damaged or wrong in the right, but it isn't in the left then you will have found the cause.
If everything looks OK, then carry out voltage tests, if you have a meter. Or a sound test. This involves touching with an insulated screwdriver the two channels while the unit is on. Never touch any part that there is only one of. Unless it's an IC and has two channels going in it. You will hear a buzz if it is working or produces sound. Again a good buzz in the left should happen in the same place as the right. When it's load at one point of a part but weak on the other, when it should be a loud buzz then you have found the faulty part.
Please however check first that it's not the headphone socket that is causing the problem. Sometimes the sound will be OK on headphones but not on the speakers. The socket the headphones fit into can cause this.

I would prod and poke the channel with an insulated screwdriver this will cause buzz sounds. This should find the cause of the problem. Remember that the left hand channel is identical so you can compare the right with the left. For example if you get a weird buzz on the right when you touch it, but not on the left at the same point you might have found the faulty part.
Don't go near the power supply section as it's nothing to do with that the fault.

The problem will be in the power amp for the the left channel. One you have identified this on the circuit board you can compare the channel with the right. As they are both the same. Start with a visual check. If anything looks odd compared with the the right replace it. Distortions are often caused by a burned resistor. Though the main power transistors or IC can cause it too. If you can't find anything visual I would replace the main output device(s) for the left channel.

It's likely there is a fault on the power amp. This is located on the heatsink. A visual check inside the unit might be what you need. Look out for blown parts, bulging capacitors or burnt components. Remember the two channels are generally separate and identical. So identify the two channels. Work back from the speaker sockets if you can't tell. Then compare the left channel parts with the right side components. If it looks odd on the left compared to the right you have found the problem.

Hey, I had that same problem and looked over it with my Dad, who's very technically minded. Here's what he found:

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We also had no/weak sound on the left channel of the I-Trigue 3300 2.1. Here's what we found (starting where you left off...).

The internal bias for the input pin for the left channel on the M51132L (pin two on the M51132L between the heat sink and the connectors) appears to have failed. It was sitting at an operating point of around 11 volts (should be 5.4V as the others were) and was only capacitor coupled to other nodes (the input at 0V bias and the chips reference on pin 4 at 5.4V) so it wasn't a case of capacitor leakage. Our temporary fix was to hang a 10k resistor between the node on pin 2 (with the failed bias) and the node on pin 4 (a good bias source). The easiest place to hang it was across the cap that connected to those two nodes. That pulled pin 2 far enough from the rail (down to around 9 volts) to allow it to work at the levels we drive it at while we look for a replacement part. The expectation is that with this kludge in place the left channel will distort before the right one will when the drive level is increased however, for the tests so far, the right and left channel now both work equally well.

Cheers!
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Hope this helps you!
-David S

Im not finding answer for you problem either, but its sound like a broken cylinder.

i wold pull the orfice out of the burner and check for a partial obstruction hold it up to the light look down in the burner tube

all of the channel are resonding to the test. but you cant notice it bec 5.1 speakers, each channel are designed to respond to a certain frequecies.  the L/R channel your talking about have the mid-range frequecies so it responds clearly compared to other channels...

 

hope that helps...