Coolermaster Extreme Power Plus 550W design problem

[c_hegge]

Re: Coolermaster Extreme Power Plus 550W design problem

Good find.

Try http://uk.farnell.com/bourns-jw-mill...-15/dp/1189587

That's about the only one which matches the inductance, and has the pins in the correct position (most other coils mount lying down on the PCB)

EDIT: You might also want to check the other PFC parts too (The transistor, diode and capacitor)

[Nikochan]

Re: Coolermaster Extreme Power Plus 550W design problem

Would this help to figure it out? Schematics are towards the end of the document. You can search for RP-550-PCAA-E2 in the PDF which is the product number of the PSU.



There is a section around the coil on PCB that marked as L13 and according to the above document, the coil could be either one of these:

CH270060 (page 146)
CS270060 (page 149)
T106-52 (page 152)

The one I have resembles the T106-52 though.





This is a document for T106-52 core which indeed matches the size of mine.

https://cdn.badcaps-static.com/pdfs/...43fffdea41.pdf

[ben7]

Re: Coolermaster Extreme Power Plus 550W design problem

I don't think I have a dead PSU that features Active PFC on it. Would Farnell or Digikey have anything to replace that?

Yes they likely would, BUT you would have to get the schematic of this PSU to determine what inductance it has, and other core material properties, etc...

[Nikochan]

Re: Coolermaster Extreme Power Plus 550W design problem

I don't think I have a dead PSU that features Active PFC on it. Would Farnell or Digikey have anything to replace that?

[goodpsusearch]

Re: Coolermaster Extreme Power Plus 550W design problem

This is the APFC coil. You should find a replacement coil from a dead psu. You could try to rewire the coil, but the core material is probably affected too.

[Nikochan]

Re: Coolermaster Extreme Power Plus 550W design problem

This is a rather crappy picture of the PSU. The burnt coil marked with the red arrow.

[Nikochan]

Re: Coolermaster Extreme Power Plus 550W design problem

My sis had one of these, Cooler Master eXtreme Power Plus 550W (RP-550-PCAA-E2) to be more specific. She told me that it smelt bad and got very hot, so I replaced it with a Seasonic.

When I opened it up, aside from lots of cheapo Capxon caps, I saw this coil, glued between two heat sinks which was almost charred. It probably was the source of the smell. Other than that the PSU looked okay.

Recently, I've been thinking of repairing it by replacing the coil, but seeing this thread has made me realized that it probably has serious design problems, so perhaps wouldn't worth the effort.

Although, as PSU was in a working condition before I replaced it with a new one, I still want to give it a go. What I would like to ask is, is there a way to identify that coil? I don't know if it had markings on it showing the specs, as it got burnt they are no longer there. I'll try to post a picture of it.

[Behemot]

Re: Coolermaster Extreme Power Plus 550W design problem

^ In terms of the bridge rectifier but I'm not sure if that applies for the rest of the PSU, though 230V is definitely more efficient than 115V. I don't understand why these APFC coils run so hot? Are they all really that hot in every APFC PSU? Makes APFC PSUs look like an unattractive option which is sad considering how omnipresent they are today.

The boost effect is being achieved through the coil, so yes, the lower the input voltage, the higher the stress on the coil to obtain 380-400 V.

[cheapie]

Re: Coolermaster Extreme Power Plus 550W design problem

I don't understand why these APFC coils run so hot? Are they all really that hot in every APFC PSU? Makes APFC PSUs look like an unattractive option which is sad considering how omnipresent they are today.

I used to have an OCZ OCZ700MXSP ("ModXStream Pro" 700 watt, made by Highpower). It had APFC, and it ran fine on 120V. Then again, I don't think I was even drawing 200 watts...

Also, are you SURE it has APFC? Hardware Secrets says it doesn't have any PFC. Looking at their picture, I don't see any PFC either.

[Wester547]

Re: Coolermaster Extreme Power Plus 550W design problem

^ In terms of the bridge rectifier but I'm not sure if that applies for the rest of the PSU, though 230V is definitely more efficient than 115V. I don't understand why these APFC coils run so hot? Are they all really that hot in every APFC PSU? Makes APFC PSUs look like an unattractive option which is sad considering how omnipresent they are today.

[Behemot]

Re: Coolermaster Extreme Power Plus 550W design problem

When some ppl said it is working fine, and some not. What is your mains voltage?? If 230 V, than the coil is not that much stressed as on 110/115 V on which it is at least two times as stressed.

[everell]

Re: Coolermaster Extreme Power Plus 550W design problem

Here is a picture of two APFC coils in series in a Delta power supply. They were definitely burned, probably shorted. I tried winding new coils, but they also ran very hot. I was using cores from junked out psu's, so the core quality was probably very poor. I ended up completely replacing them with commercially made "booster coils". Still runs hot but has not burned up. I think there is not enough engineering done on these booster coils for long term service. Just get it out the door and sold. Then worry about heat problems later.

[shovenose]

Re: Coolermaster Extreme Power Plus 550W design problem

I've come to the conclusion that these are simply crappy power supplies.

[ben7]

Re: Coolermaster Extreme Power Plus 550W design problem

BUT, is the coil burning then the transistor shorts, or was the coil just running warm then it burnt because the transistor shorted? Unless the coil solder joints are broken before the transistor shorts, I would try upgrading the switching transistors.

The dc resistance of the coil is low, so when the mosfet would short, there would be a large current in the coil. So large that the fuse will blow before the coil will even get hot.

[everell]

Re: Coolermaster Extreme Power Plus 550W design problem

Every APFC circuit I have fixed had burnt coil and shorted FET switchers. Replacing the FET transistors did not solve the problem as the new FET transistors shorted.
The coil always showed some signs of being burnt, and the short was always near where the coil wire was soldered to the pc board. Measuring with an ohmmeter or DVM is useless because you can't distinguish between low resistance reading and shorted coil. BUT.....I purchased a Ring Tester....and without taking the coil out of the circuit, a shorted coil indicates short whereas a good coil has a good ring.

[999999999]

Re: Coolermaster Extreme Power Plus 550W design problem

BUT, is the coil burning then the transistor shorts, or was the coil just running warm then it burnt because the transistor shorted? Unless the coil solder joints are broken before the transistor shorts, I would try upgrading the switching transistors.

[everell]

Re: Coolermaster Extreme Power Plus 550W design problem

What brand and model. Need some pictures. Booster coil running too hot then causing FET to short is not an unusual problem. My OPINION,,,,the core material used is cheapo, the wire may be undersized, and you are expecting too much from what is there.

[Th3_uN1Qu3]

Re: Coolermaster Extreme Power Plus 550W design problem

Is it possible to put serial resistor between rectifier and this choke for current limiting, so It will not burn?

No. Well, perhaps... if you're willing to burn A LOT of power.

[aanev]

Re: Coolermaster Extreme Power Plus 550W design problem

Is it possible to put serial resistor between rectifier and this choke for current limiting, so It will not burn? How to calculate resistance and wattage of this current limiting resistor ?

[uligli]

Re: Coolermaster Extreme Power Plus 550W design problem

Mine has been working without issues more than one year, almost 12 hours every day.