Ok Armadillo... why i should measure across pin 1 and 8 can you explain?? (u know i'm newbie )
is this my IC datasheet ? https://www.digchip.com/datasheets/download_datasheet.php?id=1913236&part-number=IRIS-A6351
(i will do measurement tomorrow morning.... do i have to take care about some high voltage during measurement??)
Thank's for suppport!
Turn off the AC power,
pull out the plug. You MUST discharge C1 for your safety. After the proper discharge, then you can start to measure the ohms.
Please note that this power supply is HOT, even the IC is HOT, meaning it is connected to the AC mains, of high KVA, and can cause serious damage. So be very careful with it.
Because the circuit tried to start up, but there is a over-current situation that forbid it to start up [when pulse voltage at pin 1 exceed 0.7 volt]. Either the mosfet is shorted or the PWM frequency has degraded too low. You will most likely be looking at either the IC or the transformer. Either one will be hard to get. The IC is obsoleted. [ok one other measurement, you can measure the current sense resistor R7 that it is 0.9 ohms and is not open circuited, for double sure its not external circuit causing the problem]
And because the 3.3v power supply off ebay is getting so cheap, it is not worth the efforts to repair it, really.
But if this is just for your learning, I will say, please find yourself a more safer circuit to start off with.
Edit: you know why I ask you to test it without buying the capacitor? yeah! because there may be some other important and deterministic parts to consider, like the IC or transformer.