What are these VR's for ??

[fulfunc]

I have a Sparkle Power FSP300-60ATV which is a little low on the +12v but good on the +3.3v and +5v.

Inside, on the main board, there are 3 trim pots, VR1, VR2, and VR3.
The board indicates it is a Rev.2 series.
The caps appear OK as do the resistors.

Before I start playing with it, does anyone know what each of these pots is for??
1 is beside the power in, 1 is beside the main chip/ P-OK wire, and 1 is beside the 3.3v sense(at the front panel)

Any help would be greatly appreciated ....

[Per Hansson]

Re: What are these VR's for ??

Is this the same PSU as here or different one?
https://www.badcaps.net/forum/showthread.php?t=52699

[juliadream]

Re: What are these VR's for ??

Well lets see.. It's a PSU so the best guess is.. they will be in the sense/feedback circuitry for the different voltage rail regulators, and perhaps the one on the "HOT" side of the psu could be to set the switch mode oscillator frequency..

I'm starting to smell fried technician.. take great care if you don't have an isolation TX !!