One channel thermal overload stays lit and no output from that channel. even after unit sits overnight, thermal light on immediately,unit not hot. Looking for schematic?

The thermal coil that tells the gas valve to stay open when the piolet light is lit is bad. Go to the hardware store with your model and serial number, they should be able to sell you a new one. They don't cost much.

the thermal couple is likely bad .
when you release does pilot stay lit or only as long as you hold the button .

if it stays lit then the thermal couple is good
if it only blows out as you turn on the heat then its draft issue.

What is the speaker load in Ohms that you are running? Or what exactly is hooked up to it? are you bridging it? The protection light will come on if the load is too much for the amp to handel. If the load (in Ohms) is less than the rated load that it can run, it will stop the output to keep the amp from self destructing. The amp will sense that the demand for power will be too high for the amps circuitry which will either make the amp get so hot that it will burn up the copper on the board or more likely burn up the power mosfetts that power the speakers. If the Ohms are within range then it will allow power to flow through the circuit until the rails that the mosfetts are bound to until they get so hot that it will go into thermal protection. So if your amp has both thermal and overload protection lights and the overload is light then the load is probably too much for the amp. if it's bridged in mono the you can only have 1 speaker setup hooked up it if it's a 2 channel amp. a 4 channel amp bridged in mono for both front and rear channels will be able to have 2 speakers rated a 4 ohms each hooked up to the amp 1 set per bridged output or channel.
Try it running in stereo with only 1 speaker per channel and see if it will produce sound. If not then you have an amp that has internal problems and will need to be serviced. Check your warranty to see if you are covered.

if any one of the channels was shorted out, even momentarily, that channel's output transistors would likely be blown causing it to stay in protection mode. (or overload as you put it). Time to visit the repair shop.

lost the 2nd PSU ?
standby power must be present
and BMC heart beat too flashing,
if not the PSU is bad or have shorts in the system.

the BMC is first, we go there read the logs
if BMC is dead we diagnose that reading the HW service manual free.
not having 2nd PSU, is super bad, and is hot swap PSU.

Generally speaking, an amp attempts to protect itself from heat, shorts, overloads and operator exuberance by refusing to turn on or stay on.

Overloads can be from excessive periods of high output or marginally low impedance loading by the speakers; and shorts would be wiring issues or a speaker blowing up.

You should be able to feel if it's hot. WHY is it overheating? Make sure it has sufficient ventilation on all sides and that vent holes are not blocked by dust balls. Ensure the fan (if equipped) is running as designed (some only operate on demand). Clean dust and debris from it.

If the amp comes back on after cooling, you're lucky. They only have so many self-protection cycles in their lives so continuously resetting or cycling their power without addressing the cause can do more harm than good.

If it protects immediately on a cool power up you should disconnect the speaker connections and try it 'nekkid'. If it comes up then diagnose which lead(s) are shorted. If it does not come up the problem is internal and should be left to an experienced and competent hands-on tech.

If pilot lights and flame is robust and clear blue, and pilot goes out later, then some suspects can be excluded: air in gas line, low gas pressure, thermocouple is overtightened (finger-tight + 1/4 turn), thermocouple not positioned correctly in the flame, dirty pilot tube.
If flame is yellowish and small: then clean pilot tube and combustion parts.
http://waterheatertimer.org/How-to-install-gas-water-heater.html#clean
Remaining suspects can include: air in gas line, low gas pressure, bad gas control valve, tight house so household vent fans pull air down water heater vent that blows out pilot, hot attic with inadequate ventilation, water dripping down vent.

Open following links to read troubleshoot resources.
http://waterheatertimer.org/pdf/Pilot-light-will-not-stay-lit.pdf
http://waterheatertimer.org/How-to-install-gas-water-heater.html#troubleshoot

sounds like a locked rotor, did the compressor get hot? did you check max amps on the compressor when it attempted to start?compressors have thermal protection built into their windings, a switch that will open to protect the compressor, and if the rotor is locked, normally you have to replace it, you could try putting what is called a start assist capacitor on it (AKA hard start kit) I would recommend the two wire model, easy to install.
You will need to wait for the thermal overload to reset, turn power off to unit till you get the kit on there.

The pilot must encompass the thermocouple "bulb" in order for the thermocouple to generate enough current to keep the pilot valve on. You must also hold the red button down for a long enough period to get the thermocouple hot. If the pilot is not large enough, it could be due to a clog in the pilot orifice at the pilot itself. Sometimes a couple of passes over the end of it with fine steel wool is all it takes to clear it.

Hope this helps. Feel free to share what you found. Thanks.

is the burner assembly sitting pronperly on it;s cradle,, this will put it at just the right distance for it to ignite,,