CoolerMaster RS-450-ACLY PSU issue?

[alindumitru46]

The PSU is old , was received in good condition and the seal is intact. I did not want to open it, I just blew it with a compressor.
Meanwhile, I used it on different systems or to test various components.
As you can see it is a wide range of voltage source with 90 ~ 264V, active PFC and ATX2.0 standard-a fixed 24pin connector:
http://www.coolermaster.com/service/...l/RS-450-ACLY/.
I measured it with a DMM but with a dedicated tester - Thermaltake Dr.Power 2, and values are ok.
Works fine, but using of certain motherboards (DFI P35T52RL BloodIron, DFI NF4-SLI Expert and other old 2 to 3 mobos) fails to power on, restarting continuously, as if a malfunction of the motherboard.
What can cause this to occur?!
Thanks.

[zx8401]

Re: CoolerMaster RS-450-ACLY PSU issue?

I wonder if the Power Good line is a little too low in voltage for some mobos?
Perhaps its triggering the restarts perhaps.

[stj]

Re: CoolerMaster RS-450-ACLY PSU issue?

maybe the "tester" is not putting a heavy load on the supply lines.

[alindumitru46]

Re: CoolerMaster RS-450-ACLY PSU issue?

Where is the difference here?!
This configuration: CPU E8400, Asus HD2400Pro low profile, 2GB DDR2, 1HDD:
- with Gigabyte GA-x48-DQ6 , x48 chipset, works perfect;
- with DFI P35T52RL BloodIron, P35 chipset, power on issues.
A 350W no name PSU runs perfect in both configs...
Maybe DFI drain a high curent at start and the Cooler Master cannot sustain the peak values neccesary for power on because is too weak to "keep" the voltage in parameters, strictly for boot?

[stj]

Re: CoolerMaster RS-450-ACLY PSU issue?

i think you need to open that psu - if it has no warranty then you have no problem.

[momaka]

Re: CoolerMaster RS-450-ACLY PSU issue?

maybe the "tester" is not putting a heavy load on the supply lines.

That's not a maybe, sir. That is for sure .
Those PSU "testers" are hardly useful for anything.

So I agree with what stj said - open that PSU up and show us pictures. No point in trying to figure (or is it guess?) why a no-name 350W PSU runs those PCs but this PSU doesn't.

[alindumitru46]

Re: CoolerMaster RS-450-ACLY PSU issue?

Yes, boss!
Encouraged by @STJ, I open the PSU last night for take some shots. I was scared how compact it and I quit at this time to take pictures, although I did not see a bloated capacitor or any unusual discoloration on other pieces.
But for a proper diagnosis I know that it is necessarily a good set of pictures.
I tried to take some pictures right now.

[momaka]

Re: CoolerMaster RS-450-ACLY PSU issue?

Wellp... no bad caps - at least not bulging ones. Nothing else seems obviously wrong. Perhaps change the really small caps first. Some of them are responsible for filtering power to the various ICs on the PSU, and if they are bad, they can cause the IC(s) to mis-behave.
Or, if you don't have any of those small caps in stock, then perhaps try changing the output caps first. Ltec is not a very reliable brand... though they do better than CapXon and Teapo most of the time.

Also, check the solder joints on the bottom of the PSU. Let us know if you find anything suspicious (or perhaps post pictures, if unsure).

Lastly, what CPU does the DFI board have? I'm pretty sure this PSU should be powerful enough for it, but nonetheless, I am curious. And graphics card?

[stj]

Re: CoolerMaster RS-450-ACLY PSU issue?

put your psu tester back on the 24pin cable,
and load it up by connecting one of the 4pin cables to a harddrive.
see if any of the voltages change.
if not - add a second drive.

you get the idea.

[alindumitru46]

Re: CoolerMaster RS-450-ACLY PSU issue?

1. BloodIron runs with E8400 or E6300 and NF4SLI Expert with Athlon 3200+, Newcastle core. I know, Expert explicitly required to connect both 12V connectors for CPU, or motherboard is not guaranteed to boot, even if the CPU does not ask that much power. The PSU has 1 connector for 12V for CPU, another is with a molex cable adapter.
If the NF4SLI Expert can has multiple issues, the Bloodiron can keep easy a 500MHz FSB with cheap PSU...
I'll try a visual examination for solder joins with a magnifier. I think a cold joint can be a major issue even for a psu...

2. Good ideea , . I think to cross-connect the 12V cpu connector from Coolermaster psu to another mobo, that will be powered by another psu only by ATX 24 pin connector.
The charge will increase too much to easy identify a issue.

[momaka]

Re: CoolerMaster RS-450-ACLY PSU issue?

2. Good ideea , . I think to cross-connect the 12V cpu connector from Coolermaster psu to another mobo, that will be powered by another psu only by ATX 24 pin connector.
The charge will increase too much to easy identify a issue.

That is actually an excellent idea!
That way, the Cooler Master provides the majority of the power, but the other PSU tells it when to turn ON and OFF. Just make sure to connect the PS_ON wires of both PSUs together if you want this to work.

[kaboom]

Re: CoolerMaster RS-450-ACLY PSU issue?

Ltecs, and little Ltecs are probably conspiring to take the great CoolerMaster down!

PG is likely dropping out (ripple or outputs out of tolerance) and those certain boards are forced into reset.

PS "testers" are nothing but pretty lights; who needs one when those Ltecs are in plain sight?


Ltec= Lousy, Trashy Electrolytic Capacitor

[alindumitru46]

Re: CoolerMaster RS-450-ACLY PSU issue?

The weekend is near, expect some proposals replacement for suspected capacitors that would be the origin of the failure.
Thank you.

[momaka]

Re: CoolerMaster RS-450-ACLY PSU issue?

So how did you conclude it was the caps? Did you try the experiment in post #10 and 11?

[alindumitru46]

Re: CoolerMaster RS-450-ACLY PSU issue?

Ups... , well I have not checked .
I get home only on weekends, only then I can handle things like that.
But I was thinking about getting ready, just in case .

[alindumitru46]

Re: CoolerMaster RS-450-ACLY PSU issue?

First test config: MSI 770T-C45, Sempron 3000+ cpu, 512DDR2 ram, 6600GT 128ram PCI-e video.
First try:
1. CM psu 24pins+12V cpu: short spin of fans +hdd and shut down;
2. CM psu 24pins only: power on, spin of fans+hdd, no boot;
3. CM psu 24pins+12V cpu from another psu: short spin of fans +hdd and shut down;
4. another psu 24pins+12V cpu CM psu: power on, spin of fans+hdd, no boot, the CM has short spin of fan and shut down;
Second try:
1. CM psu 24pins+12V cpu: short spin of fans +hdd and shut down;
2. CM psu 24pins only: short spin of fans +hdd and shut down;
3. CM psu 24pins+12V cpu from another psu: short spin of fans +hdd and shut down;
4. another psu 24pins+12V cpu CM psu: power on, spin of fans+hdd, no boot, the CM has short spin of fan and shut down;

Second test config: BIOSTAR NF6IS Micro 754, Sempron 3000+ cpu, 512DDR1 ram, 6600GT 128ram PCI-e video.
First try: CM psu 24pins+12V cpu: runs perfect and a maximum overclock of cpu from 1800MHz to 2215MHz (limited by mobo).

Third test config: Gigabyte x48 DQ6, E8400 4GHz@1.18V cpu, 2x2GB @1066MHz, 6600GT 128ram PCI-e video, 2HDD, 2fans of 120mm and 70mm, wc pump 12V.
First try: CM psu 24pins+12V cpu: runs perfect .
BIOS voltages:
cpu core: 1.888V;
ram: 2.128V;
3.3v rail: 3.280V;
12V rail: 12.112V

[momaka]

Re: CoolerMaster RS-450-ACLY PSU issue?

Based on those ^ tests, sounds like your MSI 770T-C45 has a shorted MOSFETs in the CPU area.

Take your multimeter and set it on lowest resistance scale. Measure the resistance in the 4-pin CPU 12V connector between 12V rail and ground - i.e. put red (+) probe on 12V pins and black (-) probe on ground pins. If you get a low resistance (less than 100 Ohms) and it stays that way for more than 10 seconds, then you likely have a shorted upper MOSFET in CPU VRM.

As for the CoolerMaster PSU - looks like it is working fine. If you have access to good Japanese caps only, then you can recap it now. But if all you have available around you is Teapo, OST, Lelon, or similar brands, then probably no point in recapping it.

[alindumitru46]

Re: CoolerMaster RS-450-ACLY PSU issue?

I measured with psu connected, without power on mobo, and there I found 157ohm.
Must power on the mobo for correct value?

[momaka]

Re: CoolerMaster RS-450-ACLY PSU issue?

No, *never* measure resistance with power ON. Disconnect the PSU as well and re-take measurements.

[alindumitru46]

Re: CoolerMaster RS-450-ACLY PSU issue?

8.21kohm stabilized.

It was about to commit ... to give a hammer in my balls

LE: Between 2 forum posts I quickly repaired two psu, firecracker type : one with wires "baked" and other with 3 swollen capacitors.