Hp server power supply mod.

[Eldorado828]

Did the 750 watt version, PL-18. Jumper-ed the resistor by the pot. Adjusted to 13.85. Works well up to about 15-20 amps, then starts buzzing and cuts off.
I didn't do the Over Voltage part as 13.8 was all I need to go. It doesn't drop hardly at all as far as voltage, just starts to squeal and cuts out. I think I might have got a bad one, I guess there's probably a reason there's so many on the market, probably quite a few out there that were replaced due to not being able to do the 55 to 65 A.
Just a thought, maybe I'll go back in and do the OV part, although I didn't think it would need it as most of what I've seen doesn't require that part of it until going above the 13.8V.
Not a big deal, just thought maybe I'd goof around with one of these for fun, and at $18 I can't kick for just the experience. Maybe I'll drop to 12V and see if it still cuts out.

The crowbar protection affects both the amperage and voltage. From my understanding, both parts have to be done.

 

[Smokinone]

The crowbar protection affects both the amperage and voltage. From my understanding, both parts have to be done.

If I hold it close to my ear, well several inches away, I can hear like a buzzing or humming sound while it is unloaded at idle. Like you, this is my first one so i don't know what to expect.
I'll play around a little more with it and see what happens. It can't keep up with the 2970 as it is.
I borrowed the hookup to the bar from your post, put some Anderson 45A power poles on the ends with 10 ga, and added a switch to the jumper part for on and off.

EDIT: lowered voltage to 13.5 and it no longer cuts out at the 15-20A, however I get a lot of chatter when doing so. OVP mod from Hopper to come.

 

[Eldorado828]

Did the 750 watt version, PL-18. Jumper-ed the resistor by the pot. Adjusted to 13.85. Works well up to about 15-20 amps, then starts buzzing and cuts off.
I didn't do the Over Voltage part as 13.8 was all I need to go. It doesn't drop hardly at all as far as voltage, just starts to squeal and cuts out. I think I might have got a bad one, I guess there's probably a reason there's so many on the market, probably quite a few out there that were replaced due to not being able to do the 55 to 65 A.
Just a thought, maybe I'll go back in and do the OV part, although I didn't think it would need it as most of what I've seen doesn't require that part of it until going above the 13.8V.
Not a big deal, just thought maybe I'd goof around with one of these for fun, and at $18 I can't kick for just the experience. Maybe I'll drop to 12V and see if it still cuts out.

Mine makes a minor crackling noise when idle but I assumed it was just it's nature because it works just fine.

Your supply is completely different and different mods as well. Below is the modification for your specific model.

 

[Smokinone]

Mine makes a minor crackling noise when idle but I assumed it was just it's nature because it works just fine.

Your supply is completely different and different mods as well. Below is the modification for your specific model.

Did this mod, I get chatter from the power supply when I start pulling amps. I can only conclude the pwer supply was bad, or I did something to it. I modded it before trying to pull any amp draw when I first got the power supply.
Might be an RF thing as It doesn't chatter until I start to modulate with the amp at lower power. I have the voltage at about 14.2V, draws down to about 13.5 when doing about 400 W into the dummie load.
It does hold and doesn't cut out like it was though, so it cured that part of it.
I moved the power supply under the desk with the same results...oh well, nothing ventured, nothing gained.