Antec SL450P Smart Power Exploded!

[goodpsusearch]

Re: Antec SL450P Smart Power Exploded!

Hello. I repaired and recapped 1 of 2 Antec Smart Power SL450P.

I replaced every cap on it, including the 2 small caps of the pfc board.

I was lucky enough to find 2x560uF 200V Panasonic caps to replace the "470uF" Fuhjyyu main caps. I also found a Panny bipolar 1uF cap that was needed by that psu.

I added a 4 pin connector to make the psu compatible with 24 pin (20+4) motherboards.

Last thing I did, I added 2 resistors in paraller with RTH2 to mod the fan controller so that the fans move faster. I tried 5.6 and 4.7kohm in parallel giving a ~2.5kohm total resistance.

RTH3 seems to be an over temperature protection sensor.

I attach photos of the psu.

[goodpsusearch]

Re: Antec SL450P Smart Power Exploded!

I tried to fix the second psu...

I checked every single cap with esr/capacitance meter and replaced the bad ones, checked the schottky diodes and transistors for shorts and finally plugged it in, after putting a bridge rectifier in place of the pfc wires.

5vsb should come up, but it didn't.

I checked every component in the 5vsb area marked in the photo . Those with green are the ones that were tested and found ok. With orange are the ones that I was not sure if they were good, couldn't tell with my testing equipment and testing them on board. The bad part (marked with red) was a 4.7ohm resistor that was found open. I replaced it today and plugged the psu again...

Sparks, loud noises and smoke worse than anytime before .... The room still smells burnt electronic parts..

So, I don't think there is anything I could do for that power supply.

The attached photos are for Toasty who wanted to see blown parts

I am wondering what was the reason of that catastrophic failure...

[Toasty]

Re: Antec SL450P Smart Power Exploded!

Was that opto blown before or after the "repair"? Huge chunk missing from the bottom.

Thanks for the pics!!!

EDIT:
BTW: A low-ohm resistor is typically a "fuse" of sorts. Notice that the resistor you replaced is fed from the outside leg of the bridge rectifier. It's load is the transformer. That being blown is a clue as to a problem with either the trafo load exceeding the rating, or perhaps a shorted transformer winding.

[goodpsusearch]

Re: Antec SL450P Smart Power Exploded!

Was that opto blown before or after the "repair"? Huge chunk missing from the bottom.

Thanks for the pics!!!

EDIT:
BTW: A low-ohm resistor is typically a "fuse" of sorts. Notice that the resistor you replaced is fed from the outside leg of the bridge rectifier. It's load is the transformer. That being blown is a clue as to a problem with either the trafo load exceeding the rating, or perhaps a shorted transformer winding.

The optocoupler was ok before the last attempt to power on, same as the other burnt parts...

Maybe the 5vsb transistor was bad, even though it wasn't found shorted...

[mur]

Re: Antec SL450P Smart Power Exploded!

If making Toasty happy isn't so important to you , it's a good idea to put a standard lightbulb in series with the power supply at the mains input. If something shorts out the mains, the lightbulb will just light up and there wouldn't be so much damage to the psu.

[everell]

Re: Antec SL450P Smart Power Exploded!

I have had the same kind of experience when trying to fix those 2 transistor 5vsb circuits. You have to find and replace ALL bad components, or you end up putting pieces of transistor into orbit on the second power up! My secret is to gut the 5vsb circuit and replace it with a PWM IC (such as DM311) on an add-on board.

I traced the circuit and drew what I had in my Antec SL400. Perhaps this will help you.

[goodpsusearch]

Re: Antec SL450P Smart Power Exploded!

Thanx! Do you think it's the same model with yours?

[everell]

Re: Antec SL450P Smart Power Exploded!

Mine does not have the Power Factor Correction circuit. Here are two photos of mine after a complete recap and the modified 5vsb circuit board.

[stj]

Re: Antec SL450P Smart Power Exploded!

you know, i was reading this thread earlier and there was a big bang.

amazing timing for the shit 12v power brick running my monitor to blow it's fet!

[ratdude747]

Re: Antec SL450P Smart Power Exploded!

someone's luck just went bad... you can fix it... assuming it didn't take anything out with it...

[everell]

Re: Antec SL450P Smart Power Exploded!

Luck?????

The problem is BAD CAPS! Otherwise none of us would have found this website. Thanks Topcat

[goodpsusearch]

Re: Antec SL450P Smart Power Exploded!

At least I fixed the other one...

[stj]

Re: Antec SL450P Smart Power Exploded!

well this thing terminated itself.
the fet went, the fuse exploded,
somehow a spark arked from the fuse into the main cap body and out from the other side of the cap into a resistor - it's total toast!

luckily i can get them cheap enough not to give a shit.

[ratdude747]

Re: Antec SL450P Smart Power Exploded!

somebody is having a bad day...

here, a good song that will cheer you up, from the USA!

http://www.youtube.com/watch?v=ZzU9FgNTYrU

the pics are bad, focus on the song.

[goodpsusearch]

Re: Antec SL450P Smart Power Exploded!

The fuse did not blow. The electric panel's breaker (10Α) went down and only then the flames stopped..

thanks for the song!


http://www.youtube.com/watch?v=Htm8Gb5gNQA

[goodpsusearch]

Re: Antec SL450P Smart Power Exploded!

Hello. I got another Antec SL450P Smart Power!

It had completely dried primary capacitors, the 5vsb critical cap was also completely dead and there was one more tiny 1uF cap at the secondary that had gone high esr (27 ohm!).

I replaced those caps with temporary tested good ones and then connected the psu at the mains in series with a 60W bulb. The 5vsb came on correctly! I was afraid it was gonna explode as it happened with the previous antec smartpower I was trying to revive...

But when I reconnected it with the power on signal shorted to ground the 60W bulb came up as if it was connected to the main socket.....

Does this mean there is a short? Isn't there any oportunity that the pfc needs higher input voltage and produces this?

Maybe I should test it with a higher wattage lamp?

[goodpsusearch]

Re: Antec SL450P Smart Power Exploded!

UPDATE!!!

I doubled the wattage of the lamp by connecting in parallel 2 60W lamps (total 120W) and fired it up again:

The power supply works, the fan moves normally, but the lamps light as if they are connected at ac alone.

Should I try it without the bulbs?

[ben7]

Re: Antec SL450P Smart Power Exploded!

UPDATE!!!

I doubled the wattage of the lamp by connecting in parallel 2 60W lamps (total 120W) and fired it up again:

The power supply works, the fan moves normally, but the lamps light as if they are connected at ac alone.

Should I try it without the bulbs?

Check to make shure the secondary rectifiers or caps are shorted, if not then, I dont know what else would make it blow, maybe a problem in the driver circuits.

-Ben

[goodpsusearch]

Re: Antec SL450P Smart Power Exploded!

If the secondary rectifiers were shorted the short circuit protection should have kicked in....

The caps are ok.

[goodpsusearch]

Re: Antec SL450P Smart Power Exploded!

It works