Job lot PSU no.1: Tagan BZ800

[Khron]

If a couple weeks ago it was LCD's, this week i scored a grand total of 6.7KW of (dead) PSU's from the same company, plus a 20" HP LCD and a Dell Latitude D620, all for ~85$

First on the operating table, the Tagan BZ800 (OEM = Topower).

5Vsb is powered by an ST Microelectronics ViPer22A chip, PFC/PWM's a CM6800. Protections are handled by a PS232 chip.

5Vsb works just fine, puts out 5.116v. Upon shorting the green wire to ground, nothing happens. PFC works fine, i've got 387v on the main filter cap. 12v's around 0.4v and dropping, 5v and 3.3v even lower.

Cap-wise, a blend of Hermei and CapXon.
- 12v = 2x CapXon KF 3300u/16v -> Panasonic FK 2200u/16v
- 5v = ditto
- 3.3v = 2x Hermei LE 3300u/10v -> Rubycon MBZ 3300u & 2200u/6.3v
- 5Vsb = 2x Hermei LE 1000u/16v -> Sanyo ME-AX 1000u/6.3v
- -12v = ditto -> Sanyo ME-WF 1000u/16v

Plus a 470u/400v JunFu, a 10u for the CM6800 and a 22u for the ViPer22A.

Post-recap - same thing

Attachments = top / bottom view, pre-recap.

[Behemot]

Re: Job lot PSU no.1: Tagan BZ800

That's some ugly mess on the backside of the board.

Can't see behind those sinks, are there any small caps, preferably arround +5V SB circuitry, which may be baked?

[goodpsusearch]

Re: Job lot PSU no.1: Tagan BZ800

MBZ is a bit too low esr to recap a psu.

Check for shorts everywhere. Does the fan move instantly when you connect green wire to ground?

[Khron]

Re: Job lot PSU no.1: Tagan BZ800

There were two small caps, that 10u and 22u, but those were the first i changed (10u/50v Nichicon PS and 22u/63v Panasonic FC)

I know the MBZ's might've been a tad too low-ESR, but those were the only two caps i had in close-enough uF ratings AND in 10mm diameter.

Good call on the short-checks It seems one of the switching FETs might've "let out the magic smoke" - it shows 3,6ohms drain-to-source.

Next step - primary silicon & heatsink extraction, to confirm...

[Th3_uN1Qu3]

Re: Job lot PSU no.1: Tagan BZ800

If one of the FETs blew also check the current sense resistor while you've got the heatsink out - a shorted FET usually blows a fuse, unless it's blown something else first, and the current sense resistor is usually the first to go.

[Khron]

Re: Job lot PSU no.1: Tagan BZ800

Haven't finished extracting the primary heatsink & silicon yet, but the current sense resistor seems fine, at 0.12ohms (measurement agrees with the color coding on it).

[Khron]

Re: Job lot PSU no.1: Tagan BZ800

Well, during the holidays, dad got me four STW20NM60 fet's, since one of the 20N60C3's in this psu seemed to have kicked the bucket.

Now, i just got back to my place on thursday. Last night, i got around to finishing extracting the primary heatsink. To my confusion and dismay, all primary silicon checked out fine

Culprit ended up being one of the two "reverse" diodes in the double-forward converter

The originals were UGP20K's. Odd thing is, the silkscreen seems to have been made for "fatter" axial diodes (think 3-4A size).

Unfortunately, i didn't have anything in stock at those values (min. 2A / 800v), since i understand they need to withstand double the B+ rail (and with the PFC on, that's close-enough to 800v. I ended up ordering some UF5408's from fleaBay; i just hope the Trr won't be too horribly mismatched (75ns vs. 35ns on the originals).

With a bit of luck, i'll have some updates next week

[Khron]

Re: Job lot PSU no.1: Tagan BZ800

Great news - UF5408's arrived today. Stuck'em in, soldered the primary heatsink back in, and the results...IT'S ALIIIIVE!!!

And here's photographic proof (take note of the "bling factor" )

[everell]

Re: Job lot PSU no.1: Tagan BZ800

Great job on that repair, Khron666. And all those lights make it downright purdy!

[Khron]

Re: Job lot PSU no.1: Tagan BZ800

Another lesson learned...

Can't wait to get my company established - i've got a ~100eu-worth shopping list of caps i need to order from Farnell, and i'd like to avoid the VAT After that, i can start work on the rest of the PSU's that are resting under my bed (600/850w Solytech, 600w Silverpower, and two FPS Everest 1010w).

[Freddie]

Re: Job lot PSU no.1: Tagan BZ800

Hello khrone666,
I have read the above story about the BZ800.
I have the same situation and also my Tagan has a bad 20N60C3 power transistor.
First i i placed a new fuse. After that a resistor exploded. Now i tried to dissambled some parts and find the corrupt transistor. But now i was to enthousiast and found that small
Transformer td03 / 744.
It has a silver side and thought it was burned. I was trying to get it out and with my thick fingers i broke it some parts.
My question now is do you have some technical plan of the pcb, aspecially about the small transformer.
If so can you share that information.

Thank you

Greetz fom Holland.

[Khron]

Re: Job lot PSU no.1: Tagan BZ800

There's a lesson in there: never replace a fuse before you determine what made it blow

The small transformer = the tiny one right next to the main transformer? See the picture in the first post.

[Freddie]

Re: Job lot PSU no.1: Tagan BZ800

Yes that is the one i mean.
I think that the info on the trafo is to little to tell anything about it.
Wrote to Tagan but not a response at all.

[Khron]

Re: Job lot PSU no.1: Tagan BZ800

That's the transformer that drives the gate of the upper FET. You can see the way it's connected in the application notes for CM6800 or FAN4800.

There's no reason to hope to get any info from Tagan themselves, they just put their name on it. As you can see in the first post, the manufacturer is actually Topower, but i highly doubt you'll get any info from them either...

[Freddie]

Re: Job lot PSU no.1: Tagan BZ800

Well after some searching on the internet i found a review of this psu and they wrote that it was made by the company ABS.

http://www.bjorn3d.com/2007/11/abs-t.../#.UU67o3y9KSM

http://www.pcper.com/reviews/Cases-a...-Supply-Review



Well I think that all the parts are made somewhere in china.
So now i wrote them a mail. Maybe i get a answer. You never know.

[Khron]

Re: Job lot PSU no.1: Tagan BZ800

"ABS Gaming Labs"? "You may recognize ABS from their long affiliation with Newegg." That doesn't really sound like a power supply manufacturer to me

As i said, the "physical" designer and manufacturer of the PSU is Topower. They're the most likely to HAVE any answers; if they're willing to share them, that's a totally different story.

The psu is made FOR Tagan, and that ABS thing is just some sort of "brand-name certification" whatever... Like Fatal1ty or Republic of Gamers and so on

I wouldn't waste my time trying to contact companies who just put their name on the label and cash in the profits.

I know that at least the sizes are similar, and possibly even the pinouts, but... If you can get your hands on another CM6800-based PSU, you *might* be able to "transplant" that gate driver transformer.

[c_hegge]

Re: Job lot PSU no.1: Tagan BZ800

Yup. It's a Topower alright. You can tell by the "TOP" Markings on the main Transformer.

[ll111]

Re: Job lot PSU no.1: Tagan BZ800

Hello, it's an old topic, but I would be grateful if someone who has BZ800 PSU can tell me the resistance of the resistor on the attached picture (outlined with red), or the color of its 5 bands. I've left the blown resistor on the table to check it later, but my wife managed to throw it away before I did. Any help would be much appreciated!

[carbys]

Re: Job lot PSU no.1: Tagan BZ800

Hi, I'm aware that it's an old topic, but i have a tagan bz 700 is similar to the model 800. The problem in my psu comes on, but fails to approximately 10 ms later, attached to the motherboard goes in a loop start stop of the psu. Nothing seems to have seen the circuit or capacitor failure swollen. I disassembled and controlled bridge rectifier and diodes and MOSFETs are working on the primary, I disassembled the optocouplers and are functioning in the secondary I disassembled the capacitors and various transistors and MOSFETs and are operative, for safety I changed all the capacitors but the problem remains, the power standby is functioning in fact turns on the motherboard on stand by, I would try to change the idea of the integrated pWM NCP1203p60, I would like some suggestions from some of you, thanks.

http://1drv.ms/1Yv51yV

[Stefan Payne]

Re: Job lot PSU no.1: Tagan BZ800

Yup. It's a Topower alright. You can tell by the "TOP" Markings on the main Transformer.

Yeah, Topower P6, similar to be quiet Dark Power (Pro) P6 up to 600W...
The 750W and up had an other layout witch was indy regulated...