Testing SMPS

[terry]

I read some where that you can test a SMPS transformer was light bulbs, I repaired all the faulty part in the SMPS but still not working. (I think the transformer is faulty). Can I test the transformer input this way, if I check it with a multi_meter there is about 330v DC there.

[hazi12]

Re: Testing SMPS

So it does not try.
Measure the control circuit and also the secondary part of the transformer short-circuit diodes.
Bulbs for output transformer by tension.

[budm]

Re: Testing SMPS

So you are using the lamp to test the B+ feeding the Power MOSFET DRAIN PIN through the power transformer primary winding in the Primary side of the circuit (one side of the lamp is connected to the primary side circuit GND), be real careful due to the cold resistance of the lamp which is very low so it will draw lots of high inrush current. Do you have 330VDC between the two wires (Black and Red) of the lamps and how many watts are these lamps?
SMPS POWER Transformer very rarely goes out. since you do have B+ (330VDC rectified from the main AC line.
So did you check the VCC pin of the SMPS IC to see what DCV you are egtting and if it is high enough to kick start the IC? How about the startup/running cap connected to the VCC pin of the SMPS IC. You also check other components as well, I.E. DIODES, RESISTORS,ETC.?