Check R9 and R10.
Check R9 and R10.He said there is 340V at mosfet, therefore those are fine. and I think you mean R8 and R10.
Pins 2 and 4 are not power pins, therefore nothing extraordinary. Space between rectifiers and those resistors is very small, so it's very unlikely to use that as reference in measurment. Moreover, there won't be 340V as capacitors won't have any way to charge. But otherwise it's impossible to measure 340V, voltage would be much lower.
It's not a weak link. Don't you see that it's 0.05 ohm 10W in total? It's for current sensing. And there is a fuse which will blow much faster. Max continuous current for those resistors is 14A and will survive 10x higher higher in peak.
It's not a weak link. Don't you see that it's 0.05 ohm 10W in total? It's for current sensing. And there is a fuse which will blow much faster. Max continuous current for those resistors is 14A and will survive 10x higher higher in peak.
You can't straight 1 + 1.
These things run at elevated temperature and need to be derated. That's must be why its 2, adding surface areas. Have you not seen it failed before?
Don't confuse 50 mohm current sense resistors with inrush current limiting resistors of significantly higher resistance. And I already said why they cannot be faulty given measurments made.
Actually the switching power supply does not need the power factor controller to function, its sole purpose is to improve the Power Factor by timing boosting the voltage.
The ML4824 is a Power Factor Correction and PWM Controller Combo, and as such controls the FPC, and also outputs signal to IC30 (IR2109) Half-Bridge Driver, for the SMPS Mosfets.
The question is what OP considers as no voltage. Pin 2 is current input and voltage normally won't exceed 0.6V, don't know if OP wrote about pin 4 correctly.
Without optocoupler being on/shorted, there is no chance this PSU running.
No voltage on pin 4 can be explained buy faulty R46/R47 which can happen much more often that faulty R8/R10 and can happen by itself, without power components failing.
Try shorting optocoupler as suggested. This will ensure that PSU is always on. And will help to rule out possible control circuit problems. Also it seems that some of the voltages mentioned on the table are from standby PSU and are not present on attached circuit diagram.
I do not own a variac, and I do not have any suitable incandescent light bulbs to put in series at this point in time. In my home I only use CFL's. And as such I am somewhat reluctant in trying to force the smps to start up.
I have redone the tests again with another DMM.
It does seem that I am now getting voltages on Pin 2 & 4 of IC1, but each time I power cycle the TV the voltage values change.
Thanks again.
LOL, I think it is the reverse, do not short to ON.
you say that you would like me to test voltages at IC2 this appears to be for the STD-5v output, if this was faulty surly I would not be getting the STD-5V voltage output, as listed in the above tests.