Ultra Xfinity 600w 5vsb mod

[mockingbird]

Re: Ultra Xfinity 600w 5vsb mod

with the primary heatsink out, it is easy... I won't reinstall it until after i have those spots re-filled with caps (good ones)... for now, the heatsink and attached goodies are sittign on the shelf next to the rest of the PCB.

my question is regarding using nichicon pw for those 2 start up caps. Will those be ok? they are 105 C rated...

Always replace small GP caps in PSUs with Nichicon PW...

Witht the small values, PW class caps serve essentially as a heat-tolerant, highly reliable cap.

[ratdude747]

Re: Ultra Xfinity 600w 5vsb mod

ok, tonight I will place the order.

I am correct that I should replace the tiny 1/2W 100 ohm load resistor with a 1W equivlant? (I included it in the order). I am also wondering if there is a way to place a heat sink on the resistor?

[c_hegge]

Re: Ultra Xfinity 600w 5vsb mod

^either that or desoldering braid (which is what I use).

@ratdude. Nichicon PW will be fine. I use their Panny equivilant, FC for startup caps and it's fine.

[shovenose]

Re: Ultra Xfinity 600w 5vsb mod

Suck? So I need a solder sucker?

[brethin]

Re: Ultra Xfinity 600w 5vsb mod

Quick question: how do I desolder the doodads on psu heatsinks? There are too many legs to heat all at once...

You heat and suck each doodad then it will freeup and come out for you.

[shovenose]

Re: Ultra Xfinity 600w 5vsb mod

Quick question: how do I desolder the doodads on psu heatsinks? There are too many legs to heat all at once...

[ratdude747]

Re: Ultra Xfinity 600w 5vsb mod

I believe those two caps are the start caps for the switching transistors. I when recapping Antec StupidPowers, I usually use de-soldering braid on the legs and they just fall out. The replacments can be a bit hard to get in, but it's perfectly doable when the legs are long enough.

with the primary heatsink out, it is easy... I won't reinstall it until after i have those spots re-filled with caps (good ones)... for now, the heatsink and attached goodies are sittign on the shelf next to the rest of the PCB.

my question is regarding using nichicon pw for those 2 start up caps. Will those be ok? they are 105 C rated...

[c_hegge]

Re: Ultra Xfinity 600w 5vsb mod

I believe those two caps are the start caps for the switching transistors. I when recapping Antec StupidPowers, I usually use de-soldering braid on the legs and they just fall out. The replacments can be a bit hard to get in, but it's perfectly doable when the legs are long enough.

[ratdude747]

Re: Ultra Xfinity 600w 5vsb mod

I struggled with two small caps on an SP450 in a similar tight spot... Anyone who's re-capped the SP450 knows what I'm referring to...

Actually it was a lot easier to desolder the two little Fuhjjyu caps than I imagined. Locate the pads for the two caps underneath and mark it. Heat both the pads at the same time (This is easy with 5 x 11 caps, just add solder to bridge both leads so that when you heat one, both of them become molten) and while it's molten, it only requires very slight pulling pressure from the right side up of the PCB to get the cap out of there. It may even fall out on it's own.

Now when both caps are out, use wick to clear the holes... Now, it's a lot easier than you think. When you get the replacement caps with the long leads, you leave the leads on, and the leads are in effect your "tweezers". Manoeuver them in there. You don't need tweezers.

I removed the primary heatsink and then used the quoted method to reove the caps, as they were a tight fit.

i was also able to super glue the lifted traces back to the board.

FYI, it uses 2 10uf 50v caps. added to order. had to use nichicon PW since that value doesn't exist in nichicon HE.

[mockingbird]

Re: Ultra Xfinity 600w 5vsb mod

short of a hacksaw, I doubt it... they are more or less enclosed, and due to the shape of the heatsinks and the sixe of the transformers (the heatsinks cover parts of the transformers), gettign in there without sawing heatsinks will require desoldering.

nof if the traces hadn't lifted (punched through, that is, due to a soldring defect), it would be no big deal. however, since one of the anchor traces is an island, it may come off with the solder if I am not careful... hence the issue.

I struggled with two small caps on an SP450 in a similar tight spot... Anyone who's re-capped the SP450 knows what I'm referring to...

Actually it was a lot easier to desolder the two little Fuhjjyu caps than I imagined. Locate the pads for the two caps underneath and mark it. Heat both the pads at the same time (This is easy with 5 x 11 caps, just add solder to bridge both leads so that when you heat one, both of them become molten) and while it's molten, it only requires very slight pulling pressure from the right side up of the PCB to get the cap out of there. It may even fall out on it's own.

Now when both caps are out, use wick to clear the holes... Now, it's a lot easier than you think. When you get the replacement caps with the long leads, you leave the leads on, and the leads are in effect your "tweezers". Manoeuver them in there. You don't need tweezers.

[c_hegge]

Re: Ultra Xfinity 600w 5vsb mod

I don't know it that's what it really stands for, but HE are a high endurance series.

[ratdude747]

Re: Ultra Xfinity 600w 5vsb mod

If it doesn't have the killer cap, them just replace what you can. As for replacment caps, you won't find anything much more heat resistant than Nichicon HE (High Endurance) series.

so that's what it stands for.

tm I will desolder the primary heatsink and primary caps to get good access to the 2 little caps.

[c_hegge]

Re: Ultra Xfinity 600w 5vsb mod

If it doesn't have the killer cap, them just replace what you can. As for replacment caps, you won't find anything much more heat resistant than Nichicon HE (High Endurance) series.

[ratdude747]

Re: Ultra Xfinity 600w 5vsb mod

short of a hacksaw, I doubt it... they are more or less enclosed, and due to the shape of the heatsinks and the sixe of the transformers (the heatsinks cover parts of the transformers), gettign in there without sawing heatsinks will require desoldering.

nof if the traces hadn't lifted (punched through, that is, due to a soldring defect), it would be no big deal. however, since one of the anchor traces is an island, it may come off with the solder if I am not careful... hence the issue.

[momaka]

Re: Ultra Xfinity 600w 5vsb mod

okay... so the other question is about those 2 buried caps... gettign in there will require tweezers

There, I fixed that for you .

Actually, I didn't have tweezers for the first 2 PSU I recapped - had to use my fingers and other objects to poke and wiggle the caps out of their spots. Then, to put the new caps in, I had to use a screwdriver with folded tape on it and the new capacitor stuck to the tape to get it back in there. Wasn't too hard or anything, just a bit more time consuming.
Then I got tweezers and everything was much easier. I don't have any high-wattage irons, so for me, desoldering heatsinks or anything with large solder traces is out of the question.
Get creative and I'm sure you'll find ways to get those caps out without desoldering the heatsinks.

[ratdude747]

Re: Ultra Xfinity 600w 5vsb mod

okay... so the other question is about those 2 buried caps... gettign in there may require tweezers, as the traces holding down the primary heat sink are lifted (resoldered) and I would rather not remove it.

edit- tweezers won't work. looks like to replace thew caps, i wil have to remove the primary heatsink... which due to the iffy traces, means I could very well kill it tryign to replace those two caps.

I hate having to skimp but if you can't get to the part, you can't.

edit2- if i used braid to desolder it, i think can get back there... but i am still worried about the lifted traces... super glue?

[momaka]

Re: Ultra Xfinity 600w 5vsb mod

from what i see, the two 680uf caps are the killer caps, especially capacitor 2.

No, those are the 5vsb filter caps.

Looks like your PSU just doesn't have one, just like my Macron.

The 50v, 10uF may be for the VCC rail of the PWM controller.

Right now I have my list set to nichicon HE, since other circuits use that value; however, I may look for soemhtign more temp resistant.

Any good quality low ESR Japanese cap should be fine there. Panasonic FC and FM, Nichicon PM, PW, and HE, and Chemicon KY and KZE are what I've used in the past for small caps like that. I've also used them for the outputs too.

what I had always read is that if it is under 470uf, unless in certain cases, don't mess with it.

This doesn't apply for PSUs, though. It's better to evaluate each PSU individually.

there are 4 i cannot get specs on w/o desoldering them, 2 of which are buired between the primary heatsink and the driver transformer.

If this is a half-bridge PSU, then those 2 caps between the primary heatsink and the driver transformer should also be changed. These caps drive the switching transistors on the primary and they can diminish the PSU efficiency if they begin to develop high-ESR.
Those and the critical "killer" 5vsb cap are the only "small" caps I usually change when recapping a PSU. Occasionally, I also change the cap on the VCC rail of the PWM/supervisory IC if it's a really crappy brand (and by really crappy, I mean Rulycon and the like).

You don't need to change anything below 1uF either.

Replace the 2x 16v 680uF caps with 2x 6.3v 1000uF or 10v 1000uF caps. Should give a bit better filtering on the 5vsb circuit. Don't want to skimp on the 5vsb filtering caps, otherwise be prepared to have S3/Standby issues with your PC.

[ratdude747]

Re: Ultra Xfinity 600w 5vsb mod

well, dependign on what route i take with my older oldskool rig project, I may need the psu to be ruuning somehat soon.

looking at the psu, there are 8 tiny caps, with quite a few mounted/buiried in ways that make it ivery difficult to get any info on specs. getting them out may be a challenge.

what I had always read is that if it is under 470uf, unless in certain cases, don't mess with it.


the current part list:

4x 680uf 16v (2 in the 5vsb circuit, see post #29)
3x 3300 uf 10v
2x 6800uf 16v
1x 4700 uf 10v
1x 100 ohm 1W resitor

from the tiny caps, I can find:

10uf 50v
1uf 150v
2.2uf 50v
22uf 50v
0.22uf 50v

there are 4 i cannot get specs on w/o desoldering them, 2 of which are buired between the primary heatsink and the driver transformer.

I would rather not fuss with the tiny caps... especially the really hard to get to ones.

[mockingbird]

Re: Ultra Xfinity 600w 5vsb mod

replacing all the little caps in this beast would take forever... it is full of tiny caps.

Are you serious!? I've got like 5 PSUs here that have been sitting here for months... I've been going over the recap for a while, a little time here, a little time there. Tommorow I'm about to order $100 worth of caps, and yes, I'm replacing every little cap I can get to, except for those on the PFC and PWM vertical boards that are impossible to get to or are just coupling caps...

My point is you should take your time, plan it out carefully, research, research again, and then go ahead and recap it. I've detailed sheets for all my PSUs, diagrams of how to resolder the wires when I want to put it back in the case, detailed lists of the capacitors... Tommorow I'm making the order, and I'm still making some small modifications.

If my recap is successful, then I basically have a documented routine for re-capping that particular model.

[ratdude747]

Re: Ultra Xfinity 600w 5vsb mod

Hmm... can't you just replace all the crap caps, then it wouldn't matter which one is the "killer" cap
Even thought you're going to have a killer time replacing all those little suckers

real line one of my last post.

beat you tot he punch more or less