Bad transistor .....the amp heats up fast but will continue to work if i can get it to cool down. everything points to a bad transistor but how do i determine which transistor it is?

How long does it run, is it consistant? Some units are equipped with economizer software built into the controller/thermostat intended to capture the refrigeration effect as the internal pressures equalize. If equipped it works like this, thermostat shuts down the compressor a couple degrees above the set-point, the fan continues to run taking advantage of the continuing refrigeration provided after the compressor shuts down there is still pressure pent up the Freon continues to pass through the metering device to the low pressure of the cooling coil and continues to cool as the pressure bleeds down. If your machine does not have this feature you have a bad controller, call a tech.

If you are pulling the transistor that drives the final and the problem goes away, is the driver bad? Is the power supply a multi channel isolated unit? Could the channel for that side be bad?

It sounds like the output transistors went bad What I would do is check all output transistors in the unit they are usually the large transsistors on heat sink that an ohm meter and check each transistor while unit is off and no power go base to collector then emmiter to base if you get o or continuity on those legs on any one they are bad .

Bad heating element. Shut the power to the breaker off, disconnect the wires off of the heating element and then check for (ohms) continuity across the two element leads. If it show OL on the meter then you here is an open in the element and it will need to be replaced. Good luck.

Open the back cover & check if any of the fans used for cooling are running at low speed. Some IC's , transistors are provided with heatsinks to cool down & in between them a thermally conductive silicon paste is used to reduce the gap. If the paste has dried the related semicoductor will heat up & the TV will not work. So use a new paste for the heatsinks. Such problems are generally temperature related.

Your fan is following the heat pattern of the CPU. As your computer does more stuff, like runs more applications, it has to work harder to make everything go. This creates heat that needs to be cooled by the fan. The fan usually has 2 settings, low, and high. When the CPU reaches a certain temperature the fan will switch into high gear to help cool it down.

It's not the water pump. pumps can leak and shaft bearings go bad, but even then it is pretty much impossible that the pump won't pump. I'd start by changing thermostat. When re-filling, add coolant slowly and just when it reaches operating temp, shut it off for about two minutes. re-start, turn heater on high and continue filling till electric fan comes on (if you have one) at that point turn off again as before. Re start and run with cap off for about 15min. If overheat continues, remove radiator and flush, and bring to a shop to determine if there are any hydrocarbons in the cooling system. If so, there is a problem with either head gasket or head. (likely you will have fixed it before you get this far.)

If possible return the amp to the seller for a refund (before you tamper with it).

If that's not possible, the amp will need to be repaired. Do you want to try to repair it yourself?




For the head unit, you need to check the shield ground first. The following page will show you how to perform the test.

Shield Ground Test/Repair

Let me know if you have any other questions.

The usual cause of this is shorted output transistors. If you have experience with repairs and can solder, you should be able to repair this yourself. Open up the unit and look for the 3-legged parts attached to the heat sink. These are the output transistors. Post here the markings on those parts so I can give you the entire part number. In order to determine the bad ones, you should have an ohmmeter or diode checker. Post the parts markings and we'll continue from there.

Dan

It sounds as if there is a broken solder joint somewhere that slowly opens up with heat. The other possibility is that an input or driver transistor is dying. Since the whole channel is dying, I would guess the broken joint and/or dying transistor are near the very input of the channel.
A tech can very easily find the spot by playing the amp until it starts to die, then spraying small bursts of freeze spray, one component or area at a time, until the amp suddenly comes back to life.