Interesting CWT PSU

[Pentium4]

Got this PSU at the local recycle place for $2.95. I knew it was CWT before even picking it up, and shining my flashlight through the top, it looked pretty unique. I'll let the pictures speak for themselves mostly

Switchers are 2SC2625

16A ultra fast for 12V, two 40A schottky for 5V, and it uses linear conversion for the 3.3V with a 40A FET.

Fan is a sleeve bearing Jamicon. Will post solder shots later. I am going to recap this and use it in my Pentium III 933 rig. It's rare to find an old PIII era PSU with a quiet fan controller

[ChaosLegionnaire]

Re: Interesting CWT PSU

holy shit not one but TWO fuh-joo-yoo primaries! made me gag when i saw those lol! dammit, pentium4! lol

jokes aside, its a nice power supply. nice score btw. from the label ratings, it gives my enermax liberty a run for its money esp. since it has all the negative rails present. i still have to get around to recapping mine tho.

[Khron]

Re: Interesting CWT PSU

On the bright side, the 5Vsb doesn't have an electrolytic "critical cap", AND it's right up against the fan (so gets plenty of cooling, even passively), so it oughtta last for a while. Especially after a re-cap

[PeteS in CA]

Re: Interesting CWT PSU

Maybe August or September, 2000 vintage. I'd be wary of the GP caps between the inverter and O/P heatsinks. Decently derated O/P rectifiers. The heatsinks seem a little light for 300W, but at least they're solid extrusions, not two extrusions tongue-and-grooved together. Should be good for 250W, though.

[Pentium4]

Re: Interesting CWT PSU

holy shit not one but TWO fuh-joo-yoo primaries! made me gag when i saw those lol! dammit, pentium4! lol

jokes aside, its a nice power supply. nice score btw. from the label ratings, it gives my enermax liberty a run for its money esp. since it has all the negative rails present. i still have to get around to recapping mine tho.

Haha, sorry Wow, really? What model is your Enermax Liberty? Thanks! It was money well spent I would say.

On the bright side, the 5Vsb doesn't have an electrolytic "critical cap", AND it's right up against the fan (so gets plenty of cooling, even passively), so it oughtta last for a while. Especially after a re-cap

Yeah! Surprisingly, the Fuhjyyu caps tested good on the 5VSB circuit. Their capacitance started rising though, with one of them reading 500uF and the other reading 526uF. Both their ESR read 0.12Ω which seems about right for GP caps.

Maybe August or September, 2000 vintage. I'd be wary of the GP caps between the inverter and O/P heatsinks. Decently derated O/P rectifiers. The heatsinks seem a little light for 300W, but at least they're solid extrusions, not two extrusions tongue-and-grooved together. Should be good for 250W, though.

You got it! Forgot to mention, the marked code on the outside of the chassis is August, 2000. I will be replacing ALL caps The only caps that have tested bad so far are the 2200uF 10V Su'scon SD series, reading 2664uF and 2672uF. All the Fuhjyyu caps tested good! The only low ESR cap in here was a 1000uF 16V TMR, that read 1068uF and 0.05Ω ESR. Maybe they did that because it's on the linear regulated rail.

[ChaosLegionnaire]

Re: Interesting CWT PSU

this is the review of mine by hardware secrets. as far as the important rails and power go for a p3 system, the 5v current rating and the combined power of the minor rails match that of my enermax liberty.

[Stefan Payne]

Re: Interesting CWT PSU

I have something similar, in a PS/2 Redundant thingy (that with two PS/2 PSUs inside)...

[Wester547]

Re: Interesting CWT PSU

The heatsinks aren't only light for 300W, they're light given that a linear regulator for +3.3V is mounted on it. Interesting how 16-year old Fuhjyyus could not only look good but test to spec. We all know this is much less possible with 15+ year old KZGs, so I guess there really is a difference between KZGs and Fuhjyyu. The toroid and the windings look a bit small and thin for 300W too. Those heatsink remind me a bit of those used in early 2000s FSP/Sparkle units.

Su'scon SD is arguably low impedance but just barely (about on par with Nichicon PM/NCC LXV/LXY). SK is their true GP series. Would be interesting to see how much lubricant is left in that Kaimei sleeve bearing fan if any.

[Drack]

Re: Interesting CWT PSU

Any news of the PSU?

[Pentium4]

Re: Interesting CWT PSU

Sorry for not updating! I took some pictures a while ago and did a full recap on the thing. There were also three joints that looked like they were failing so I redid them. There were also two 1uF 50V CapXon caps in there, that tested good.

I ended up using a newer Jamicon sleeve bearing fan. It's nice and quiet! I will take a picture of the old Jamicon fan later.

It must be true that these crappy companies were better back in the day. Whether they got used or not, true Fuhjyyu would have popped. Like ones I've seen that popped and leaked after just 7 years of sitting. Anyways....pictures!

[Wester547]

Re: Interesting CWT PSU

Nice work, P4! The base of those heatsinks do look a bit thin for my liking. But if the fan controller is aggressive enough at high loads, it may be a non-issue.

I ended up using a newer Jamicon sleeve bearing fan. It's nice and quiet! I will take a picture of the old Jamicon fan later.

Yes, in my experience, Jamicon fans are even quieter than ADDA fans.

It must be true that these crappy companies were better back in the day. Whether they got used or not, true Fuhjyyu would have popped. Like ones I've seen that popped and leaked after just 7 years of sitting.

Very true, in spite of the fact that the bad brands have always been inconsistent in quality. KZGs, on the other hand (and KZJ and their variants), were always notorious for the same misdemeanor as bad Fuhjyyus (popping and leaking in unused equipment or still retaining their full leads in a sealed bag), all the way back to the year they went into production (2001 for KZG, 2003 for KZJ). Although admittedly I haven't seen a popped or failed KZG with 2009 datecodes or later so I wonder if NCC actually ever fixed them before they went out of production, but that's for another thread.

As to crap companies getting worse over time - the same goes for LTEC, Elite, Teapo, CapXon, Jamicon, Su'scon, etc - none of these brands were ever on par with the Japanese brands but they weren't alway so notoriously bad. Teapo and CapXon have particularly become replace-on-sight-pop-their-tops-in-storage junk over the years.

[Drack]

Re: Interesting CWT PSU

Must say that where I live there are so many crap caps, even no name ones, that I'm glad when I see a teapo, I think they are not that bad as they used to be, crapxon on the other hand is shit, I think that no name caps are better in some cases lol
I have a couple of kzg on two of my Mobo's, and they are OK, haven't check the date though

[Pentium4]

Re: Interesting CWT PSU

Okay so I remeasured all of the caps and listed where most of them were. I like to measure afterwards because testing them right after desoldering can be misleading.

AC filtering:
680uF 200V Fuhjyyu LP. Read: 613.4uF, 0.14Ω
680uF 200V Fuhjyyu LP. Read: 621.4uF, 0.15Ω

5VSB filtering:
Cap before coil: 470uF 16V Fuhjyyu TNR. Read: 513.4uF, 0.20Ω
Cap after coil: 470uF 16V Fuhjyyu TNR. Read: 494.6uF, 0.21Ω

Startup cap:
22uF 50V Su'scon SK. Read: 21.70uF, 1.13Ω

5V filtering:
Cap before coil: 2200uF 10V Su'scon SD. Read: 2536uF, 0.07Ω
Cap after coil: 2200uF 10V Su'scon SD. Read: 2598uF, 0.07Ω

Linear 3.3V filtering:
1000uF 10V Fuhjyyu TMR. Read: 1056uF, 0.10Ω

12V filtering:
Cap before coil: 1000uF 16V Fuhjyyu TNR. Read: 1089uF, 0.12Ω
Cap after coil: 1650uF 16V Fuhjyyu TNR. Read: 1746uF, 0.08Ω

-12V filtering:
470uF 16V CapXon KM. Read: 460.8uF, 0.18Ω

-5V filtering:
47uF 16V Su'scon SK. Read: 64.51uF, 1.00Ω

Primary BJT caps:
1uF 50V Su'scon SK. Read: 0.98uF, 3.2Ω
1uF 50V Su'scon SK. Read: 1.00uF, 3.7Ω

Others:
22uF 50V Fuhjyyu TNR. Read: 21.20uF, 1.27Ω
10uF 50V Fuhjyyu TNR. Read: 10.62uF, 1.82Ω
2.2uF 50V Fuhjyyu TNR. Read: 2.08uF, 1.43Ω
2.2uF 50V Fuhjyyu TNR. Read: 2.13uF, 1.12Ω
1uF 50V CapXon KM. Read: 1.01uF, 3.1Ω
1uF 50V CapXon KM. Read: 0.98uF, 3.7Ω

[Stefan Payne]

Re: Interesting CWT PSU

But but it's said that Fuhjyyu are not good as well as others.

But but your caps seem to be totally fine. That must be some mistake on your side!!!111


Sorry for the sarcasm, just coudn't resist

[Drack]

Re: Interesting CWT PSU

Fuhjkyou tnr on spec, wait WTF? CRAPXON KM ON SPEC?
sorry but it's really weird to see those in good shape in this forum, and don't make me talk about the suckson I hate them.
Ps. I felt that the real names are bad words, that's why they are twisted
Ps2. I know my jokes are bad

[Wester547]

Re: Interesting CWT PSU

Okay so I remeasured all of the caps and listed where most of them were. I like to measure afterwards because testing them right after desoldering can be misleading.

It's true that capacitance wise, electrolytics have a positive temperature coefficient, so until the caps themselves are at room temperature (after cooling down following desoldering), the resulting measurements can be a tad misleading.

As for the bad brands testing fine, in all seriousness, (possibly and probably) the measurement of the utmost importance in testing wet electrolytic capacitors is leakage current (or vloss/voltage loss). A capacitor can still test to spec for capacitance and impedance and still have very high leakage current (and that means the anode dielectric has a weak point, a hot spot, or is possibly damaged beyond repair). A telltale sign is how quickly they respond on the ESR meter and how fast they reach their desired values (for capacitance and ESR - if they respond slowly, leakage current is probably high). If this PSU was unused and those capacitors were just sitting all these years, leakage current is probably really high and I'm not sure if those F-you's or Suck-cons would reform all that well (but no one would ideally be using 16-year old crap brands for anything other than very light applications such as decoupling, maybe).

You are right though, Su'scons aren't good caps. They have a really high failure rate in LCDs, just like Samxon GF and GK, CapXon, Samwha WB/XC, etc...

[Drack]

Re: Interesting CWT PSU

At least samxon has some good series I have heard, almost all the samwha caps I have saw are dry or Leakey, Samsung should be ashamed