Antec TruePower 2.0 TPII-550

[Per Hansson]

Originally Posted by Wrog

Just for my understanding, what's the reasoning behind bumping up the voltage from 35v to 50v on this cap?

It is a critical cap, if it fails 5VSB will go high and kill your mainboard
Increasing it's voltage rating is a small safeguard that will make the capacitor withstand voltage spikes etc better (If memory serves, which it well might not, I think Wizard did a test where it was found that there could be quite high voltage spikes on this capacitor...)

[PCBONEZ]

The 47uF shows up in most PSUs with voltages of 25v, 35v or 50v.
Of those I think I see 35v most often.
Basically it's an important cap so there is no reason not to use a 50v as it costs no more to upgrade.
-
You don't -have- to use 50v.
The original voltage should be okay as you are getting better quality caps.

Us guys [or at least I do] that buy caps in bulk just get the 47uF 50v and use them for the 25v and 35v 47uF caps too, rather that stocking 3 sizes of 47uF caps.

So: The upgrade is routine based on practical logistics and ecomonics strategies.
- Did that sound cool, or what?
In other words it's more of a habit than a requirement.
.

[Toasty]

You got a purty mouth.

[PCBONEZ]

You're purdy cute in that helmet too!

[Wrog]

Originally Posted by 370forlife

Scorch marks might just be dried glue. There's usually not much under the main transformer, some small parts near it that may have committed suicide. Look for any burnt resistors/capacitors/diodes, etc... around or under the transformer.

Sorry, I should have been more clear -- the scorch marks that I noticed were on the bottom of the PCB. See attached pics, the non-flash picture makes it look worse than it actually is, so I included one with a flash too.

[Wrog]

Thanks for the information on selecting a 50v over a 35v, the reasons make perfect sense. While I don't buy caps in bulk, it's good to understand these things just in case I do in the future!

[370forlife]

Just looks like heat discoloration.

[Toasty]

There is either a diode or resistor mounted on end between the 2 trafos. Verify that the part is not physically damaged and that if it's a resistor, that it is in tolerance to its markings. Reflow the solder to those pins.

[370forlife]

Looking at that noflash image, that scorch is pretty dark. Definitely check out what toasty is pointing out.

[Wrog]

Originally Posted by Toasty

There is either a diode or resistor mounted on end between the 2 trafos. Verify that the part is not physically damaged and that if it's a resistor, that it is in tolerance to its markings. Reflow the solder to those pins.

Reference designator is D20. Ran out of time to do any checking on it tonight, but will definitely follow up tomorrow. Thanks!

[Wrog]

Originally Posted by Wrog

Reference designator is D20. Ran out of time to do any checking on it tonight, but will definitely follow up tomorrow. Thanks!

Seems fine physically, and on diode check it measures .549 in one direction and open in the other (seems OK). Will post again once I've recapped.

[Toasty]

Sounds good!

Please confirm that that diode is actually on the discolored area. There is another component nearby but I can't make it out. Just below that diode and right up against the transformer. Use a flashlight shown through the board to locate what sits right on the mark. Discoloration probably all caused by time/heat and not helped by the bad caps.

[Wrog]

Sorry for the long delay between followups; I had some RL stuff pop up (or pop out would be more descriptive)! The discoloration is definitely centered around D20. D21 is nearby but also tests fine. I am just now getting around to ordering the replacements, and wouldn't you know it? The UCC LXZ (565-1927-ND) is on backorder until sometime in October! I've scanned for a replacement but the specs don't seem to be as good as the LXZ in this size. Of this list, which would be the best to get (these are the 220uF 16V 6.3mm in stock at Digi-key):

Panasonic M
UCC SMG
Nichicon VR

There are a few others but are rated for only 1000 hours with a lower ripple rating. Thanks for the continued help!

[Toasty]

These are only 85°C caps. Need 105°C.

Use KMG - http://search.digikey.com/scripts/Dk...me=565-1293-ND
-or-
NHG - http://search.digikey.com/scripts/Dk...&name=P5530-ND

[Toasty]

See PCBONEZ remarks (6 & 7) on this thread regarding endurance hour ratings:

http://www.badcaps.net/forum/showthread.php?t=10764

Also, can an 8mm fit in for that 6.3mm? If so, you have a much larger number of choices.

Cheers!
Toast

[Wrog]

Thanks! I will inspect where they sit to check if 8mm diameter can be used. If they fit, would the Nichicon PW be a good choice? Actually, I think I may have some 220uF 25V with an 8mm diameter that I could use (Panasonic FM).

[PCBONEZ]

PW and FM would both work for that one.

[Wrog]

Awesome, thank you guys. All parts ordered, I'll post updates when I have some time to work on them.

[Wrog]

Had a chance to desolder all caps tonight, and found a slight surprise. I was going by PCBONEZ's list for the TPII-550 he did awhile back when I originally posted, and lo and behold, my actual list has one difference. C38 (under one of the coils) isn't a 22uF 50V as I had assumed, but rather a 1uF 50V. So his list has quantity 2 of the 22uF 50V and mine has quantity 2 of the 1uF 50V, everything else is the same. Very strange... good thing I ordered extras!

[Wrog]

Got all caps swapped out tonight, but too late to do any testing. I probed purple to ground (standby) and got 5.1v so that's a good start! Hopefully tomorrow I can fire it up in one of my PCs and report back.