Dead amp i have a pro sound 1000w amp the fan runs when switched on but thats it any ideas why no sound not even a hum !

An old elecricians joke says "do you know why it hums? It dosn't know the words" Al kidding aside ,have you checked to see how free the fan blade is? The should spin very freely. It kind of sounds to me like it may be having a hard time comming up to full speed. You may try some graphite lube on the motor. If I recall Broan has a lifetime garrentee on the motor. You might just want to repace it if I am correct.

Your gen. is a 2000 wt max 1000wt running out put. Means it will start your jackhammer but will not maintain the wattage to run it long. You are using the max it has to put out. So let me try to explain - 2000 watt max output works like this - We will use a fan as an example. A fan sitting still and not turning takes more amperage/watts to start. that is called lock rotor amps. So lets say the fan is a 1000w to run. 2000w start the fan turning then it takes 1000w to keep it turning. Your gen. can start the fan but not keep it running it is using all it has to put out, now if that fan only uses say 750 w running watts you have some head room to keep it running with out things getting hot. Hope this is clear as mud.

Anything can be repaired. Sounds like a repair is required for your SX.

If the amp is off completley it sounds like the fan is running of the incoming 12Vdc line that is constant, not switched. That would be an issue with the amp manufacturer. There is a comparator circuit that uses a Thermistor that is RTVd to the power transistors heatsink block. When that voltage reaches it's reference voltage the fan will kick on. The amp manufacturer is switching the fan supply in with a relay to the 12Vdc line (more current capability) and the relay contact is stuck closed even when you turn the amp off. Does the fan run indefinitley or does it shut off over time?

So we can help you, please post a NEW question, and please include your model number MA-1000Was well as the answers to these questions:

When you try to microwave are the inside light, internal cooling fan and turntable all working?

Is there any unusual noise or is it louder or quieter than normal?

A loud buzz, hum, or groan is usually a shorted high voltage rectifier diode, but a sound like gurgling into an empty coffee mug is one symptom of a failed magnetron, and yet the mag can be bad without that sound.

We have a sound clip of what a microwave should sound like when the cooling fan and high voltage section are working.

We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.

With power off, go on roof & try spinning fan at rear through cover with a stick, or something, until fan has made 2 or 3 revolutions, then try fan mode only & see if it starts. If no luck, remove cover on roof (watch for bees & wasps) and spin fan good by hand a few times & try again, if no luck, replace fan start capacitor.

I'm guessing the hum you hear is the fan motor. After sitting for a time, I've had many that develop like a dead spot in the fan motor. Here's what to try. Shut power off to AC. Get someone up on the roof with about a 2 ft.,long fairly strong stick, or rod , about 1/4 inch or so in diameter. Have them carefully poke it through the openings in the cover and spin the fan blades at the back end of it. May be a little stiff at first, so don't break blades on fan, but get stick under one & lift to spin it, or over it & push it downward. Spin it 2 or 3 times all the way around. Turn power back on. Now stand back & try fan mode again. 99% of the time that will do it, but if not, take screws off around cover on roof & remove cover & give fan a bunch of good spins by hand, then turn power back on & try it. Keep me posted on results please ?

Try to isolate the grounds of the amp and that of your head unit. I mean 'lift' the ground connection. Just connect the hot side and not the ground wire - your amp's grounding and your head unit's grounding might have a voltage loop. smile when the hum dissappears.

it sounds like a bad: 

•           start switch (on the side of the compressor) or
  
• ·        compressor itself
  

the start switch clicks  off usually when the compressor is pulling too many amps or the compressor is overheating. if the compressor is not even running then its probably not overheating.
·                                 so either the compressor is pulling too many amps (bad compressor) or the start switch is bad and cannot handle the amps required to start the compressor.
if you already checked this and think it is a different problem then let me know, i will help you figure it out. 
Mike  

it sounds like a bad: 

•   start switch (on the side of the compressor) or
  
•   compressor itself
  
• the start switch clicks  off usually when the compressor is pulling too many amps or the compressor is overheating. if the compressor is not even running then its probably not overheating.
  
• so either the compressor is pulling too many amps (bad compressor) or the start switch is bad and cannot handle the amps required to start the compressor.