FSP300-60PLN rev 1

[willawake]

FSP300-60PLN rev 1 300w active psu. this one was a hd killer. i recapped it without checking it out first and now it increases voltage slowly bringing the 12v rail for instance up to 12.80, the 5v does it also (i am using 22w antec psu tester to start and load the psu and checking the voltage with dmm on a molex. i did not let it increase past that anyway. difficult to troubleshoot without the prior status info i guess. is there anything that comes to mind that might save it or is it for the trash?

[larrymoencurly]

Re: FSP300-60PLN rev 1

Does it have adjustment pots, as other Fortrons do? Do pots ever go out of adjustment even when their shafts are sealed in place, perhaps because of oxidation?

A PSU I recently bought puts out slightly out of spec high voltages when loaded with 5.6 ohms each on the +5V and +12V rails, but they drop to within 2% of specs with a mobo attached and the +12V still loaded with 6 ohms.

[willawake]

Re: FSP300-60PLN rev 1

yes it has a pot on secondary side daughter board.

i am curious that the voltage is not jumping to that point but very slowly rising. say if i shut it off at 12.60 and then open it up it is at 12.60 again....

might damage a board if i connect though?

[Rainbow]

Re: FSP300-60PLN rev 1

Use dummy load to test PSUs. I use 12V/21W and 6V/15W car bulbs.

[tiresias]

Re: FSP300-60PLN rev 1

Use dummy load to test PSUs. I use 12V/21W and 6V/15W car bulbs.

That's very important Even some of the best PSUs will show less-than-glorious regulation on any major output lines when load on these rails is very low (or zero).

Car bulbs are a nice idea, since, of course, they're cheaply available and, well, they light up

For 'testing under load' of PSUs I keep a number of those porky green-lacquered wirewound fan-cooled resistors, fan-cooled (to avoid stinking up the room and enraging the wife). Typically:

1R ones for the 12Vdc rail - so they're about 140-150W each.
R47 ones for the 5 and 3.3V - about 50 and 25W respectively.

And, of course, the Fluke 337 to see what the PSU's actually up to.

[willawake]

Re: FSP300-60PLN rev 1

in the end it was multimeter needed new battery

[dood]

Re: FSP300-60PLN rev 1

haha... wouldn't have thought of that

[Rainbow]

Re: FSP300-60PLN rev 1

It happened to me too - multimeter displayed "low battery" icon, but I continued to use it. After some more usage, the voltage readings were too high. I thought that one PSU was bad, but more testing revealed that either all my PSUs suddenly gone bad or the multimeter is wrong