My pc100 does not start

[Drack]

Re: My pc100 does not start

It doesn't have a hole, the transistor is fine, most be the pwm, the mov was behind a coil, I already took it out

[Agent24]

Re: My pc100 does not start

Well that 8-pin chip on the primary side certainly looks as if it has some damage on the top. Or maybe it's just glue\paint. I can't tell, the photo isn't clear enough.

[Drack]

Re: My pc100 does not start

I looked it's glue, what I don't understand is why is just 160v on the main caps that is a 400v, shouldn't be 370ish

[Agent24]

Re: My pc100 does not start

Because your line voltage is only 110VAC and that PSU has no voltage doubler or Active PFC boost circuitry. After rectification, you get a higher voltage in DC. You can calculate it by multiplying the AC voltage by 1.414 to get the DC voltage. eg: 110 x 1.141 = 155 (about 160).
It could be that your line voltage is a bit higher than 110v, maybe 113v.


The 400V written on the capacitor just means it can handle up to 400V without blowing up.


It makes me wonder though. Is this PSU actually designed for 110V supply? Running SMPS at lower line voltages than they are supposed to run on can be stressful and cause damage.

[CapLeaker]

Re: My pc100 does not start

I looked it's glue, what I don't understand is why is just 160v on the main caps that is a 400v, shouldn't be 370ish

120V AC x 1.414 = 170V DC on the main rectifier with the unit off. Since it has a PFC, it will boost the voltage on the main filter cap to like 370V DC when turned on. If the PSU is turned on and you don't have boosted voltage on the main filter cap, then there is something wrong with the PFC IC, or the PSU doesn't get the PSon signal, etc.

[Drack]

Re: My pc100 does not start

It doesn't have PFC, the PSU say it can handle 100v/240v, it's weird, I would check everything I can today, and I will let you know if I see something weird

[PeteS in CA]

Re: My pc100 does not start

What A24 said. It's a universal input flyback design. No doubler, and no need to divide the rectified primary voltage (as would be necessary for a half bridge design). Were you in EuroLand the voltage across that cap would be on the order of 340V. Using one 400V cap instead of two 200V caps in series saves PCB space.

[Drack]

Re: My pc100 does not start

.I can put 240, I have 240 on my room actually but I'm to lazy to put a power outlet for 4% better efficiency, thanks Pete,capleaker,a24, sam, and everyone that helped me. Btw what it's newer half bridge or this?

[Drack]

Re: My pc100 does not start

Found a shorted diode