Corsair RM1000e - Help identify 5VSB Zener diode

[hobostove]

Looks like that resistor was in series with VCC going to the PFC IC. PFC IC is shorted. VCC pin is 3ohms to ground with the chip off the board. 5VSB is back with the chip off. Going to order one. I'll be back in a week

[CapLeaker]

O.k.! Time will tell!

[hobostove]

Alright, new PFC chip arrived. Put it in, and now seeing 375 on the main cap. Tester stays on steady now, but no 12V yet. More to do!

[hobostove]

Anyone have some guidance on where to start tracking down why 12V is missing? I have 5V and 3.3V

[Per Hansson]

Anyone have some guidance on where to start tracking down why 12V is missing? I have 5V and 3.3V

https://hwbusters.com/psus/corsair-r...-psu-review/3/

The PCB is small and densely populated. To save space, HEC used two vertical boards, one hosting the DC-DC converters that generate the minor rails and one with the FETs that regulate the 12V rail. The heatsinks are large enough to meet the unit's thermal needs without using excessive active cooling, hence keeping noise output low.

The 12V board is right next to the main transformer to minimize energy losses. The platform's design is the typical one: a half-bridge topology on the primary side and an LLC resonant converter. The secondary uses a synchronous rectification scheme for the 12V rail, which feeds a pair of VRMs for the generation of the minor rails

^^That would be a good start

[hobostove]

It was my crappy tester again, loose connection. I think it's time to retire it. 12V is present after all! Next step now is to load it and see what happens 🤞

[hobostove]

It's alive under load! I couldn't have done it without all of you, I learned a lot from this little detour. I feel a lot more confident approaching power supplies now. Big thanks to прямо, Per Hansson, CapLeaker, and special thanks to c1q3 for getting the ball rolling in the beginning. Sorry trash can, but you're going hungry today! 😉

Just a quick recap of everything it took:
TNY284 chip for 5VSB
Fusible resistor
15V Zener diode
2 transistors
CM6500UN PFC chip

all because someone dropped a screw in the case.....

[CapLeaker]

Great to hear you got your PSU fixed. Also congratulate yourself for sticking with it. I am sure this thread taught you a few things from different folks on how it works, what to do and learned a few things along the way. Remember the PFC in a PSU needs to work 100% first .

[c1q3]

I'm glad that you fixed it. It was pleasure to trying to solve this puzzle even if I lack of experience but there are lots of experts that approved my thought.