Left channel stopped working -- only get a static buzz our of it. Have confirmed the problem is with the power amp.

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.

As stereo amps are two mono ones put together you can use the good channel as a guide to tell you what the bad channel is not doing. You just need an insulated tool. With that and the amp on touch the left and right channels with the tool. Keep away from the power supply parts as it's nothing to do with them. You will hear a buzz if the channel works. Remember if it buzzers in the good channel it should buzz in the bad one in the same spot. You should soon find the faulty stage and part.

Yes amps buzz when something gets near them - say a pen or probe and if you know what it is safe to touch a finger! Fortunatly for you the left channel is the same as the right. So if you believe it's the pre-amp work backwards from the where the power amp connects to the pre-amp, going through the pre-amp stage by stage - prodding the parts. Remember a buzz in the right a buzz in the left! No buzz in the left but one in the right fault found!
Ignore the power supply it's nothing to do with that as it's common to both channels.

One is earth for the right, one is earth for the left, one is right channel and the other is left.
You don't need to know the colours to find the left and right channels. Just connect the turntable to the amp switch on. Then with your finger touch each wire one at a time. One will buzz on the left the other will buzz on the right. You might even get a slight buzz from the two earths.
The cartridge might have the left or right channels marked so you can connect them, but if it doesn't just connect the left to one side and the right to the other, then do the same with the earths. try it out, if the channels are the wrong way round change them, if the sound doesn't sound right change them again and again till it sounds right. You won't damage the amp or cartridge from doing this. Unless it's some kind of static effected cartridge!

The good thing about stereo amps are they are actually two mono amps joined together. So when there's a fault in one channel you have the other channel to compare it too. For example the voltages should be the same. You can also touch the working parts with an insulated tool. When you do it will buzz in the channels in places. So if it buzzers in the good channel in a certain place then it should in the bad in the same place. You can search backwoods or forwards to determine where the signal is lost in the bad channel. It should take you to the culprit part.
Don't bother with the power supply parts as they are common to both channels. Just buzz test the bad channel and compare with the good.

It looks as though you have ripple noise that amplifies into the output. First of all check if the mains voltage is going down to produce the low voltage hum. If not you will have to check the DC filter capacitors , couple in parallel to confirm the capacitor. IF the buzz is still coming through then you will have to isolate the preamp and wait it the fault is coming in. If not connect the preamp output to another amp to hear the same buzz to confirm the preamp to be faulty. If so you will have to trace by a voltage check when the buzz occurs to confirm if the preamp IC or the selector Ic is faulty. Some logic IC's can also produce this noise on static switching. If teh noise is appearing on both the channels, then I would still bet on the power section. So check once again on the rectifier/ regulators and capacitors. Hope this advice helps. Good day

If you have lost both channels then it's something that is common to both that has gone. If one channel has gone, use the good channel as a guide. Here's what to do find the point where the pre-amp outputs to the power amp. With a screwdriver touch that point (make certain you only touch one metal point at a time = don't short anything). It should buzz! work backwards till the buzzing stops. It is easier to test with a channel working, but I think you will soon get to the faulty stage.
PS IC's are allways suspect when both channels out!
PPS Don't touch any power parts with the screwdriver!

More likley that there is a fault in either the pre-amp or power amp of the left channel. To be honest with you it's one of the most diffcult problems you can have, unless you can see a burnt or damaged part. All you can do is compare the parts in the right channel with those in the left.
Touching the parts in either channel with a screwdriver (don't short any) will cause a buzz! This can be used to test the channels. Work backwards from the power amp section. Remember a buzz in the right should give you one in the same place on the left!
PS KEEP AWAY FROM THE POWER SUPPLY.
If you are not good with electronics consult someone who is.

You need to determine if the fault is in the pre-amp section or power amp part. Look around for damaged or burnt parts. If you turn up the volume on the left channel and you hear a weak signal then the pre-amp will be OK. If not then start with that section. Remember the right channel will be the same as the left so compare the parts. If it looks odd in the left it might be the faulty part!
You can apply the Buzz test! Being careful not to touch the power supply parts, touch the two channels in various places with a srewdriver. On the right you should get a buzz showing the signal is there, so touch the left in the same place! And so on...PS don't short anything with the screwdriver!

Start with the basics first. 1. With the amp on, in each imput socket plug a dual end phono cable in and touch the right and left plugs with your finger. You should get a buzz on each speaker. No buzz and the channel at that terminal is not working. If none of the terminals buzz. Then the amp is dead.
If some buzz and others not you have a pre-amp problem.
2: Amp Dead. Could be A power supply. B main pre-amp. C Power Amp.
The power supply check for a fuse.
The main pre-amp will only effect both channels if an IC controls both.
The Power Amp will again only loose both channels generally if it is an IC. It will be attached to a big heat sink and have lots of pins comming from it.
If it uses transistors for the main amp, you can check these with an Ohm meter. With the power off place the leads on each terminal of each transistor. If the meter goes fully over (like when you touch the leads together) each way it has shorted.
The thing to remember when repairing stereo amps. Is that the amp is two identical amps joined together. So what happens one side will happen on the other. If both channels don't work look for something that is common to both.
Good luck
PS never heard of 'cliperd'.