Ocz600sxs

[everell]

Re: Ocz600sxs

Looks like the same Blue Storm 2/Epsilon platform. Probably same pc board. And....bloated capacitors in the same places!

[Behemot]

Re: Ocz600sxs

Yeah there are some variations in capacitors number and position but otherwise the same. Surprisingly, the -12V cap also went bad this time

[everell]

Re: Ocz600sxs

Worked on my OCZ 700 today. Capacitors C32 and C35 were bulging and high esr, they are the two capacitors in the PI filter for the 3.3 volt rail. Same two capacitors were bad on the Antec Basiq power supply. Even more interesting, both power supplies were missing diode D35. I would have thought that D35 would be necessary for proper functioning of the psu. I am wondering if the missing diode is causing the capacitors to overload and fail. Perhaps some of our engineering geeks can enlighten us about why this diode is needed or not needed. I am including a drawing I made of the Antec psu, it is the same as the OCZ psu. Probably same as the OSZ600SXS.

[Agent24]

Re: Ocz600sxs

I think D35 is to clamp the voltage at that point, they may have found it was not necessary... or omitting it didn't cause immediate failure, so they didn't care...

I don't understand your schematic though, why does the feedback circuit feed back into the rail its monitoring? Surely the output of Q30 should go to an optoisolator somewhere.

[everell]

Re: Ocz600sxs

Finally finished work on my OCZ700. C32 and C35 were the two bulging capacitors in the 3.3 volt output circuit. I replaced C35 with a Panasonic D10 size FM series 2200 uF/6.3 volt capacitor. Previously it was a CapXon D8 capacitor but there was adequate room to install the bigger capacitor. The other capacitor C32 was a D8 CapXon capacitor with heat shrink tubing, probably to absorb some of the heat. There was no way to install a D10 size replacement capacitor, even with a shoe horn. Since I didn't have a D8 capacitor, I decided to try an alternative solution. I noticed that the silkscreen painted on the pc board had a D10 size circle where C32 should go, so I unsoldered and removed coil L31. Now there is plenty of clearance to install the Panasonic FM series D10 size 2200 uF/6.3 volt capacitor. Then I reinstalled coil L31 and resoldered. I positioned the coil such that there is a small air gap between the heat sink, capacitor C32, and the coils on the other side of the capacitor. Turned out to be much easier than expected!

Time for power up. The 5vsb came up at 5.14 volts. With 10 ohm half amp load, the voltage droped to 5.01volts. With 5 ohm 1 amp load the voltage dropped to 4.87 volts. With 2.5 ohm 2 amp load, the voltage dropped to 4.60 volts. Not overly impressive.

The power rails came up as follows: 12.39 volts, 5.06 volts, and 3.346 volts.

Voltage across the main capacitor: 168 volts with power supply off, 405 volts with the power supply on. Looks like the active power factor correction circuit is functioning properly.

[Behemot]

Re: Ocz600sxs

That's exactly why I got myself NCC KZH 1000/16 D8, it is very difficult to squeeze all D10 caps in these supplies.

Wanna some with KZN 3300/16 D10?

[TELVM]

Re: Ocz600sxs

... Voltage across the main capacitor: ... 405 volts with the power supply on ...

Is that voltage typical?

I'm asking because many APFC PSUs have a bulk cap rated at just 400V (instead of 420 or 450). Calculated risk or dangerous penny-pinching?

[goodpsusearch]

Re: Ocz600sxs

That's the reason primary caps fail often when the psu features an Active PFC.

[Behemot]

Re: Ocz600sxs

I don't think that is common, usually it is 380-390 V.

[Stefan Payne]

Re: Ocz600sxs

It's more on the high side even though it still may be OK. Bigger problem is it is only 2000 hours endurance and I don't trust these caps series, they've been spotted bad years after the problems should have been solved.

Well, according to the spec sheets I've seen, the smaller ones always have a way lower expected lifespan than the bigger ones.

For example, Nippon chemicon states that the 8mm diameter ones have an endurance of 3kh while the 12,5mm (and up) ones have 5000h endurance...

Is that voltage typical?

I'm asking because many APFC PSUs have a bulk cap rated at just 400V (instead of 420 or 450). Calculated risk or dangerous penny-pinching?

Yeah, totally.

I'd say, if you can, you should always replace the primary cap on an APFC unit with a 450V one...

[Behemot]

Re: Ocz600sxs

In this case Nichicon specifies 2000 hours for all sizes, but from knowledge we have with others caps, yes, that is good assumption that those 8mm ones may survive even less, especially in those crowded BlueStorms II, Everests and Epsilon units. On the other hand D12,5 may survive even more.

[TELVM]

Re: Ocz600sxs

I don't think that is common, usually it is 380-390 V.

Perhaps the voltage on the bulk cap is a bit higher or lower in function of the topology used or whatever?

Otherwise I'm puzzled. For instance, when crmaris reviews the relatively simple and unexpensive (~$75) L8 500W, with 400V bulk cap, he criticizes the fact:

"... The bulk cap is provided by Teapo (400 V, 270 μF, 85°C, LH series) and is rather small for the needs of this unit. Also, the voltage rating of this cap is low and close to the DC bus of the APFC circuit (~380 VDC). Ideally, a 420 V or even better a 450 V cap should be used but it is significantly more expensive, so most manufacturers prefer 400 V ones. The latter case requires a tight tolerance in the feedback/reference voltage of the PFC controller to ensure that in the cap will not take voltage beyond its rating ..."

http://www.techpowerup.com/reviews/b...L8_500W/4.html

Then he reviews the much more sophisticated and expensive (~$230) Corsair HXi 1000W, also with 400V rated bulk caps, and says nothing of the kind :

http://www.techpowerup.com/reviews/C...HX1000i/4.html


Then I lift the skirt of my L8 300W (even cheaper and simpler than the L8 500W) and find a 420V rated bulk cap .

[Behemot]

Re: Ocz600sxs

Isn't it made by different manufacturers?

[TELVM]

Re: Ocz600sxs

$350 1600W behemoth with 400V rated bulk caps? : http://www.techpowerup.com/reviews/E...G2_1600/4.html

That thing has a ten year warranty. They must be reasonably sure that 400V caps can deal with the DC bus voltage for a decade.

[Agent24]

Re: Ocz600sxs

That thing has a ten year warranty. They must be reasonably sure that 400V caps can deal with the DC bus voltage for a decade.

Maybe, or maybe they just didn't run the numbers right. Seagate used to offer 5 year warranties for everything but look how quickly they ditched those.

[TELVM]

Re: Ocz600sxs

Found this piece of info:

https://cdn.badcaps-static.com/pdfs/...25ddb0846b.pdf (page 33)

^ If I get it right sounds like the minimum voltage rating of the bulk cap/s might be related to the accuracy of the APFC PWM controller.

· More accurate APFC PWM controller => 400V might be enough to hold the position.
· Less accurate APFC PWM controller => Better use 420V or higher to prevent .

[Behemot]

Re: Ocz600sxs

Seasonic actually increased warranty to 7 years for highend, 5 years for all mainstream and 3 years even for OEM models…

EDIT: I thought Agent24 was talking about Seasonic but I see it is Seagate

$350 1600W behemoth

wut

[TELVM]

Re: Ocz600sxs



behemoth = "any creature or thing of monstrous size or power"

[Behemot]

Re: Ocz600sxs

Yeah I know what it means