Topower SilentEZ 350W: what did I screw?

[Behemot]

Been recapping this Topower https://www.hardwareinsights.com/top...z-350w-review/

Besides the usual I decided to put bigger input cap in but I got only large ones last week so besides drilling the holes for snap-in cap, I also cleared the space around a bit. What may actually be the problem is the small toroid coil between the input cap and the switching FET heatsinks: https://www.hardwareinsights.com/wp/.../Zevnitr-2.jpg I removed the plastic base, covered the coil with heatshrink and soldered directly into the board. Since than it has been assembled back together (hopefully correctly) yet the problem persist.

Now to the problem itself - PSU appears to be running, but the output voltages are just about 1/10 of nominal. I don't even get a fan twitch cause the O/P is too low. The SB rail works just fine.

So any idea what the problem may be? If it would be the coil it would make sense, it's part of the primary switching circuit.

And oh, also NTC replaced a wire jumper but the PFC circuit works fine, boosting to about 385 V when the PWR On is pulled down.

[Stefan Payne]

Re: Topower SilentEZ 350W: what did I screw?

Why even bother with this 'Thing'??

I woudn't even touch the much beefier P6 plattform...

[stj]

Re: Topower SilentEZ 350W: what did I screw?

i would look at all the small stuff around the controller that sets the voltage or handles the feedback.
or change the controller first - to save any wild goose chases - if you have one.

[Behemot]

Re: Topower SilentEZ 350W: what did I screw?

Been actually thinking if I've not somehow put the inductor turned around. I noticed in different unit (Seasonic OEM) it had different orientation. Now that does not have to mean anything, but I'll watch other units too for such coil. After all, they are all basically the same topology.

[eccerr0r]

Re: Topower SilentEZ 350W: what did I screw?

Is that inductor(transformer?) used to drive the switching transistors?
I'd imagine if that is the drive transformer and put in incorrectly, the transistors wouldn't get enough drive to fully saturate and they'd get hot (then again, depends if the output is loaded). That is, if the drive transformer was physically perfectly symmetric which I have a hard time believing so this suggestion might be completely off base...

[Behemot]

Re: Topower SilentEZ 350W: what did I screw?

Yep from quick look it is between the main transformer and the FETs too, as for more details I am not exactly sure. Them FETs do tend to get quite hot quite soon, though that may be normal, this unit does get warm as was shown in the review.

The winding seems to be wound pretty symmetric, I think I may have turned it 90° (not reversed 180°). Ceause really, what else could be bad, I have not touched anything else