Ultra Xfinity 600w 5vsb mod

[mockingbird]

Re: Ultra Xfinity 600w 5vsb mod

Maybe you put one of the capacitors in the wrong way.

[ratdude747]

Re: Ultra Xfinity 600w 5vsb mod

Maybe you put one of the capacitors in the wrong way.

then why did it do that before the recap? no change audio wise.

[mockingbird]

Re: Ultra Xfinity 600w 5vsb mod

Did you change every last cap?

[momaka]

Re: Ultra Xfinity 600w 5vsb mod

it is more like an arcing noise than a squeal come to think of it. almost like a hiss.

Ah ok. I think that's a different problem. The one and only PSU I had that made a hissing noise was a Bestec ATX-250 12Z. That one really stunk up my room when I tried to use it. I think one of the capacitors in it must have failed.

Anyways, since you changed your caps, then I don't think that's the problem. Even though you didn't change the very small caps on the secondary, that should be fine as they are running on a low voltage and it's unlikely to hear any hissing from them.

If anything, check the primary side - particularly look for long leads on neighbouring traces that look like they are very close together.

Disregard the noise? Impossible! It's REALLY, REALLY, REALLY annoying!

Yeah, I hate high-pitched noises too.
I can't hear my computers when I'm further than 3-5 feet away from them, though.

[c_hegge]

Re: Ultra Xfinity 600w 5vsb mod

It's probably feedback instability, which is often caused by either bad caps or just bad design. Someone who builds Power supplies (eg, Th3_un1qu3) would probably know more about how to fix it, but my guess is it's one of the small caps you didn't replace.

I doubt if it would really be arcing. I have a Delta-built Antec that makes an arcing/buzzing noise, but runs just fine. If it really was arcing it would fail pretty quickly.

[ratdude747]

Re: Ultra Xfinity 600w 5vsb mod

It's probably feedback instability, which is often caused by either bad caps or just bad design. Someone who builds Power supplies (eg, Th3_un1qu3) would probably know more about how to fix it, but my guess is it's one of the small caps you didn't replace.

I doubt if it would really be arcing. I have a Delta-built Antec that makes an arcing/buzzing noise, but runs just fine. If it really was arcing it would fail pretty quickly.

i have a dead delta 200w microATX unit that does this too come to think of it. its a lot louder but then again, it is also dead.

[ben7]

Re: Ultra Xfinity 600w 5vsb mod

it is more like an arcing noise than a squeal come to think of it. almost like a hiss.

Get a straw and use it to listen to the power supply parts up close when its running, you wouldn't want to get shocked on the ear!

Is it actually a steady hiss, or an arcing sound? Could be a falied ceramic capacitor on the primary flyback voltage suppressor circuit. I have found out before that cheapo ceramic caps dont like voltage near their max rating.

I suppose it could be that you replaced the secondary caps with bigger ones too. I have noticed that, say, in 555 oscillator circuits, that a decoupling cap near the 555 makes the 555 output a slightly lower frequency than without the decoupling cap.

-Ben

[ratdude747]

Re: Ultra Xfinity 600w 5vsb mod

Get a straw and use it to listen to the power supply parts up close when its running, you wouldn't want to get shocked on the ear!

Is it actually a steady hiss, or an arcing sound? Could be a falied ceramic capacitor on the primary flyback voltage suppressor circuit. I have found out before that cheapo ceramic caps dont like voltage near their max rating.

I suppose it could be that you replaced the secondary caps with bigger ones too. I have noticed that, say, in 555 oscillator circuits, that a decoupling cap near the 555 makes the 555 output a slightly lower frequency than without the decoupling cap.

-Ben

it is like arcing...

the caps (other than the 5vsb) are same values, bigger physical size. the 5vsb caps were per what i was told shoudl be swapped... but since the cap order somehow got doubled, I have the caps needed if I wanted to swap the 5vsb caps back to the stock values.

[ratdude747]

Re: Ultra Xfinity 600w 5vsb mod

i have since gotten the system's board to work... and when used, the 5vsb noise disappears. it IS a load related issue.

whew.

[c_hegge]

Re: Ultra Xfinity 600w 5vsb mod

Cool

[ratdude747]

Re: Ultra Xfinity 600w 5vsb mod

bad news. the fan controller is wasted.

that said, I do have a similar fan controller board (same PCB), but the similar one uses a bunch transistors and 2 caps, while the bad one uses an IC. also, the bad one has a 5 pin wire set to it, in addtion to the thermisitor wires and the yellow/white power wires, while the transistor one uses just the power and thermistor wires.

should i just swap and see?

[mockingbird]

Re: Ultra Xfinity 600w 5vsb mod

It doesn't hurt. Doesn't the controller just take +12V from the PSU? I wonder how the controller decides when to increase/decrease the speed.

[ratdude747]

Re: Ultra Xfinity 600w 5vsb mod

It doesn't hurt. Doesn't the controller just take +12V from the PSU? I wonder how the controller decides when to increase/decrease the speed.

thermisistor?

[Scenic]

Re: Ultra Xfinity 600w 5vsb mod

some older fortrons (235/250W for sure) had add-on "noisekiller" PCBs screwed to the heatsink. might be worth a look if you have one kicking around.

very simple fan controller. 2pin 12V in, 2pin regulated out. thermistor can be desoldered and put somewhere other than ~2cm from the fan controller board.
I kinda have to admit i stole quite a few of these out of those old fortrons for other PSUs

[ratdude747]

Re: Ultra Xfinity 600w 5vsb mod

some older fortrons (235/250W for sure) had add-on "noisekiller" PCBs screwed to the heatsink. might be worth a look if you have one kicking around.

very simple fan controller. 2pin 12V in, 2pin regulated out. thermistor can be desoldered and put somewhere other than ~2cm from the fan controller board.
I kinda have to admit i stole quite a few of these out of those old fortrons for other PSUs

the thermistor is glued in a hole in the secondary heatsink... connected tot he board by wires.

tonight i will try the swap... and if i have the caps to do it, recap the new board. maybe simple is better?

[mockingbird]

Re: Ultra Xfinity 600w 5vsb mod

thermisistor?

some older fortrons (235/250W for sure) had add-on "noisekiller" PCBs screwed to the heatsink. might be worth a look if you have one kicking around.

very simple fan controller. 2pin 12V in, 2pin regulated out. thermistor can be desoldered and put somewhere other than ~2cm from the fan controller board.
I kinda have to admit i stole quite a few of these out of those old fortrons for other PSUs

AHA! So that was what that third brown wire coming from the PSU labeled "TH" was.

They still use that same PCB on their new stuff. It has one Teapo 25V 47uF cap on it IIRC that probably doesn't need to be replaced.

[ratdude747]

Re: Ultra Xfinity 600w 5vsb mod

well, i fixed it.

the bad one had some welltrend chip on it and 2 on board thermisistors in addtion to all the transistors... all I did was splice the HS thermistor and power wires to the board and moved the 5 pin header and 2 fan sockets over from the bad board, and that did it. the 5 pins go nowhere, it is just a retainer for the cable in the psu.

the fans spun up, so far the psu is keeping cool (only being used with one cpu, gotta find some athlon MPs).

[ratdude747]

Re: Ultra Xfinity 600w 5vsb mod

i figured out what that extra circuitry on the bad fan controller was.

it was an overcurrent protection (OCP) circuit, put ont he same PCB as the fan controller.

I still have all of the OCP part ont he bad board... since the PCBs are identical, should i move the OCP parts over to the good controller the next time the computer is down?

[ratdude747]

Re: Ultra Xfinity 600w 5vsb mod

i re-added the OCP parts to the board, as i would rather not fry the psu if somehting bad happened.

the psu runs fine, i think that the psu is in good shape now.

[ratdude747]

Re: Ultra Xfinity 600w 5vsb mod

6 month Stability update.

The PSU runs fine... it ultimately ended up in a revised main rig running twin Xeons (3.2ghz gallatin core).

The only issue is I think one of the fans I tossed in is starting to go out... I may keep my eyes open for a pair of better quality PSU fans... Any Brand/model suggestions?

Side note- when I do swap fans,I may take some pics... the last batch I took was never posted (they didn't turn out).