SOURCE: DELL LCD 1901FP PlZ Find IC Number
The 8 pin IC is UC3843A, SMPS controller. The 14 pin IC is TEA1533AT.
Monitor Mike
SOURCE: i need ic used in
man that going to be amouth impossible to find because is more cheap to buy a new power supply for 25 bocks that going to kill your self trying to repair one sorry but good luck
SOURCE: pmp3000 problem power supply.ic circuit problem
I have a PMP5000 that I had to resurect. I had to trace out the power supply to repair it.
I can give you hint: First, a small supply runs directely from the line and generates some of the small voltages. While this starts, the main power caps are charged through limiting resistors. The main switcher is brought online and if the power amps acheive balance, then a relay connects the speakers and shorts the limiting resistors.
This is what is in the 5000 and I suspect the 3000 is similar.
In my 5000, there was arcing at one side of the power amps. The board was burned and three power fets fried. Cancer of burned board had to be carved out and traces replaced by hardwiring.
In addition, the limiting resistors were blown open, both main switching transistors were blown and 4 small driver transistors (surface mounted) and several diodes AND a switching regulator chip (surface mounted).all fried/
Hint: When restarting the unit, put a 150 watt light in series with one of side of the power input to limit the current in case you did not get all the dead bodies out.
This is a class "D" amp which drives PCM waves into a filter which is then the audio output. It is much more efficient thaan a linear amp.
Without a Sams Photofact or a service manual I would go directly to the Power IC which is the largest Integrated Circuit mounted to a large heat sink. If you see any fuses they are probably for the power supply since any fused circuit on the speaker output would be ineffective because the IC would be damaged before the fuse would blow, but you need to check them anyway. Since the short was at the speaker output your problem should be at the final stage of amplification, which is the Power Amp IC. Prior to the early 70's you would have transistors mounted to a heat sink which could be individually checked and replaced. Then manufactures started to use the Power Amp IC which are more costly but eliminate having to find matched pair transistors. All you can check on the Power Amp IC is if you have an input using an oscilloscope or signal tracer and the power to the IC. If you have an input signal and power to the device with no output, I would replace the IC. Unless you have a test circuit for the IC you cannot test it completely unless you have a device like a Huntron Tracker or build a test circuit using a signal generator and a power supply to measure the gain of the IC with an oscilloscope. Short of ordering a service manual this is a good place to start.
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