Tagan TG530-U15 shorted 5vsb

[Per Hansson]

Hiya, I friend to me got hold of a Tagan TG530-U15 PSU, it has been in a PC where the USB ports got shorted

I am assuming those USB ports sat on 5vsb because when I plug the PSU in and measure the 5vsb pin on the ATX connector I only see 1.8v

What could be the issue here? I took the thing apart and saw nothing wrong, looked to be in good shape...
There was a cut trace on the underside of the PCB but that must have been done at the factory for some reason, wasn't me atleast

Btw, it's an odd layout IMO because it's a full range APFC PSU with no voltage select switch but it still has 2x bulk caps @ 1000uF 200v...

[i4004]

Re: Tagan TG530-U15 shorted 5vsb

did we just receive an answer to my question if 2xcap can be used in a-pfc circuit too?
that would be cool and there would be no need to investigate tough subject of a-pfc!

about tagan; find what chip is driving 5vstb transformer(usually one nearest to that transformer), get its daatsheet and then check voltages.
(first thing, offcourse no need for datasheet to do that, would be to check +3xx V supply...one the bulk caps...perhaps a-pfc circuitry is out of order to begin with...)
voltages are big there, so you need to be carefull.
gas-mask, rubber gloves and stuff...hehe...

overloading of 5vstby circuit shouldn't produce ill effects in normal circumstances as it has protection via pwm-ic chip.

and...post some pix anyway. easier to work on it when you see it..heh

[Per Hansson]

Re: Tagan TG530-U15 shorted 5vsb

Right now I can't get any pics of it, and I didn't take any of it because I did not have my camera with my at my friends place where the PSU is now...

But I found a review of it, tho that one actually is not a PFC model!
On my friends version there was no selector switch plus there was an additional PCB in there housing the APFC stuff!

http://www.dansdata.com/tagans.htm
(Oh, and unless you have adblock and it's updater installed don't click that link, or your eyes will forever become damaged and you might get severe physiological problems!)

[gonzo0815]

Re: Tagan TG530-U15 shorted 5vsb

Wasn`t Tagangan using Fuckyou capacitors?

Any way, APFC is no vodoo, it is simply an controlled step up buk regulator making a fixed voltage for the second stage usually higher then the highest peak value of the mains.
You can put any capacitor after it, in fact you can put any older non PFC PSU design after it, as long as it can bear the higher voltage. If not it is possible to set a lower voltage too.
So there is no problem in using two capacitors in series, but usually two pieces of capacitors are more expensive then one. Thus most actual APFC PSU`s are using one single capacitor, except the very high power ones.

I have a very cheap PSU laying around, death with bulged secondary craP capacitors.
But it has an very simple APFC circuit attached on a separate PCB assembly and it uses two smaller capacitors in series due to space considerations.

[i4004]

Re: Tagan TG530-U15 shorted 5vsb

can't see it from dan's pix, and even if he got the correct angle i think those massive sinks would obscure the view.

dangerous link, you say? dunno...i use ie6 with activex turned off and nothing bad happened. as for ads, oh i'm sure i've seen worse...

[Per Hansson]

Re: Tagan TG530-U15 shorted 5vsb

Ya, I was being a bit ironic, but see his main page, www.dansdata.com
It's quite hideous really! (green flashing ads)

Anyway, the PSU was using TEAPO's for the secondary, dunno about the primary

[starfury1]

Re: Tagan TG530-U15 shorted 5vsb

the use of 2 caps has a couple of problems I think

1 you will have to use Twice the capacitance for each Cap for same capacitance
(so finding a place to put them in there might be a real drama)

2 you may have to (as far as I am concerned) force equal voltage sharing via voltage
divider other wise it becomes at the wim of the caps what voltage exists across each.
(you may get away with this if they are same type caps)

anyway just my thoughts and I am no guru on it.

Cheers

[starfury1]

Re: Tagan TG530-U15 shorted 5vsb

Well I cant tell much from those Photos Per so no idea

this thread has photos in it,
it looks similar so maybe you can work out from that what the 5V STB is
(I think it might have a second transformer for it but don't know for sure)

https://www.badcaps.net/forum/showth...ighlight=Tagan


Did you check this 5V while not connected to MB?

If it uses a 5 Volt 3 terminal reg, these are short circuit protected but the current rating may be increased by a transistor....I dont know
(I never shorted out a psu +5 STB to see what happens either)
(reason I ask is maybe something on MB is kaput)

still, do the other voltages check OK on PSU

I guess you need to ID how the 5 Volt STB is being supplied. I don't have a clue.

BTW the unit brian C shows photos of uses a UC3842 and a TL494

unit has an "Auto switch" for Voltage Input selection
(So I think it was Bridge Rec Voltage doubler Config depending on I/P mains voltage)

So check this against the unit you got Per

Cheers ...I'll have to re read that thread

[starfury1]

Re: Tagan TG530-U15 shorted 5vsb

since it seem to be raised here

here the wiki on PFC, couple of PDF at the bottom

http://en.wikipedia.org/wiki/Power_factor_correction

first one is fairly extensive, might be of use to you I4004

Cheers

[i4004]

Re: Tagan TG530-U15 shorted 5vsb

so here
http://www.fairchildsemi.com/pf/UC/UC3842.html

per, i don't think you'll be able to troubleshoot this without voltage measuring...



fury, onsemi pdf seemed good to me
https://cdn.badcaps-static.com/pdfs/...25ddb0846b.pdf
got it yesterday, still didn't read important sections thoroughly, but it looks promising.
they put accent on the harmonics, not phase(which a lot seem to be doing).
on their oscillographs current and voltage are clearly in-phase.
but we can discuss that in other thread, if need be, after i read this more thoroughly...

[Per Hansson]

Re: Tagan TG530-U15 shorted 5vsb

Thnx
No, and I wont be able to trouble shoot much without the PSU either

The PC it was in survived, new PSU and it booted up just fine apparently
The PSU does not power on, not even with no mainboard connected

5VSB was measured with nothing attached to the PSU, well, except the power cord :P