Antec "Stupid" Power rebuild

[LDSisHere]

Hello all,

I am in the process of attempting my first power supply rebuild but I am not sure it will work when I get done. I was hoping that I can get some input as to what components may be bad other than the capacitors or if it is toasted beyond repair.

The supply is an Antec Smartpower SLP-450WR out of an Antec home brew DVR case. This one is odd in that both the input power and output power are on the same side of the supply. This was given to me by a co-worker and I would like to put the case to use and a standard supply would have to be modified if I went that route. Plus, I have always wanted to fix a power supply after seeing so many fail.

The first thing I did with the PS was to attempt to use my ATX tester, but I could not get to that point. As soon as power was connected to the supply, it would squeal, very loudly. I opened up and found it was full of what I refer to as the F*** U brand of caps. It had one Teapo that held up well but the other big low voltage caps were bad. (See the pictures.) (I plan on replacing all the lytics, even those disgusting 200V F*** U caps.

My concern is the heat spot and the components in that area. I am not sure how bad the damage is nor what I need to check to find out. This area had the two small 10V 1000uF that are open both physically and ESR wise. I am not even sure the discoloration is due to heat or capacitor electrolyte leakage. I have read that when caps open up like this they tend to take out other components, which is why I am hoping for some pointers at this junction. Hopefully the pointer recommendations will not be "toss it out," but that is an option.

I wish the pictures were better but due to circumstances beyond my control I had to take the pictures inside and my battery was dying with no way to recharge it at present. If better shots are needed of certain areas or parts, let me know and I will get them ASAP.

Thanks for your time,
Lloyd

[goodpsusearch]

Re: Antec "Stupid" Power rebuild

If I were you I would recap it and test it. You can use used cheap caps just to see it is ok before proceeding in full recap with japanese quality caps.

Check the mosfets with the diode mode of your multimeter for shorts.

[bigbeark]

Re: Antec "Stupid" Power rebuild

You will find that badcaps.net is about the only place you can get the replacements for the skinny 3300uf & 4700uf 16v caps.

This thread is helpful : https://www.badcaps.net/forum/showth...mxon+rs&page=3

Main thing is to be sure to replace every single fuyuhu cap especially the little ones

[mariushm]

Re: Antec "Stupid" Power rebuild

Like he said. Replace the capacitors.

4700uF 6.3v will be a bit hard to find in that small diameter, in my opinion you can safely use 3300uF 6.3v capacitors there.

If it's still gonna whine, might be some inductor vibrating - it may have been glued down before the glue hardened and cracked or something like that.

[c_hegge]

Re: Antec "Stupid" Power rebuild

4700uF 6.3v will be a bit hard to find in that small diameter, in my opinion you can safely use 3300uF 6.3v capacitors there.

This. I do it all the time when I can't squeeze 4700uF caps in.

[LDSisHere]

Re: Antec "Stupid" Power rebuild

Thanks for the input everyone. I had already figured that the 4700uF were going to have to drop to 3300uF. I am still debating if I should replace the Teapo as it tests good and it I will have to replace it with a 12.5mm. Concerning the little caps, I have already seen a lot of post about the need to change these so I was planning on it. It is a good thing to point out however, in case I had not seen posts about that already.

C Hegge it seems like I read a post earlier (today?) where you added a resistor to a supply like this to make the fan run or am I mistaken? If so, is there a thread with instructions for this mod? I do not remember reading anything about how to determine where to solder the resistor in the thread I read. Very good Idea as it seems they want the power supplies to cook themselves to death in a timely fashion.

After seeing this supply, I want to tear my son's apart and see if it needs caps also before I place my order. It would be a power supply preventive maintenance recap.

I will post back about my progress or setbacks as I try and figure this out. Thanks again for all the help and the link.

[dmill89]

Re: Antec "Stupid" Power rebuild

Thanks for the input everyone. I had already figured that the 4700uF were going to have to drop to 3300uF. I am still debating if I should replace the Teapo as it tests good and it I will have to replace it with a 12.5mm. Concerning the little caps, I have already seen a lot of post about the need to change these so I was planning on it. It is a good thing to point out however, in case I had not seen posts about that already.

C Hegge it seems like I read a post earlier (today?) where you added a resistor to a supply like this to make the fan run or am I mistaken? If so, is there a thread with instructions for this mod? I do not remember reading anything about how to determine where to solder the resistor in the thread I read. Very good Idea as it seems they want the power supplies to cook themselves to death in a timely fashion.
After seeing this supply, I want to tear my son's apart and see if it needs caps also before I place my order. It would be a power supply preventive maintenance recap.

I will post back about my progress or setbacks as I try and figure this out. Thanks again for all the help and the link.

Here's a link to an old thread I had on this:
https://www.badcaps.net/forum/showthread.php?t=19499

It is on an SP-350 but they are similar

You run a 2200 ohm resistor in parallel with the thermal resistor which "tricks" the fan controller to speed up the internal (front) fan and kick on the exhaust (rear) fan. You can use different values of resistors lower resistance = higher speed but I and others have found that a resistance of around 2200 ohm to be the "sweet spot" where noise and cooling are balanced well.

[LDSisHere]

Re: Antec "Stupid" Power rebuild

You run a 2200 ohm resistor in parallel with the thermal resistor which "tricks" the fan controller to speed up the internal (front) fan and kick on the exhaust (rear) fan. You can use different values of resistors lower resistance = higher speed but I and others have found that a resistance of around 2200 ohm to be the "sweet spot" where noise and cooling are balanced well.

Thanks, that is what I was wanting to know. My supply has a single 120mm fan, will this trick work for me also? It seems to me like it should unless this fan setup is controlled differently.

[c_hegge]

Re: Antec "Stupid" Power rebuild

^
It should do. I've done it with both the SL-350 and SP-350, and it worked with both of those. I'd imagine the fan controller in this is similar, so try it with a 2.2K. 2K and 2.4K will also work (the former will run the fan slightly faster, the latter will run it slightly slower than a 2.2K).

Thanks for the input everyone. I had already figured that the 4700uF were going to have to drop to 3300uF. I am still debating if I should replace the Teapo as it tests good and it I will have to replace it with a 12.5mm. Concerning the little caps, I have already seen a lot of post about the need to change these so I was planning on it. It is a good thing to point out however, in case I had not seen posts about that already.

I'd replace the teapo. Better to spend an extra $1 or 2 now and not have to take it apart again. The small caps should also be replaced. They can cause either annoying high pitched squealing, or worse - a 5vsb overshoot (a condition where the 5vsb voltage increases to 12V or higher, which will kill your motherboard)

[goodpsusearch]

Re: Antec "Stupid" Power rebuild

https://www.badcaps.net/forum/showth...?t=8385&page=2

"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."

[LDSisHere]

Re: Antec "Stupid" Power rebuild

https://www.badcaps.net/forum/showth...?t=8385&page=2

"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."

Goodpsusearch,

Thanks for this link. I have started reading through it and I noticed that you had ran across a bi-polar capacitor. Is that a common occurance on Antec "Smartpower" or was that because those were older pre-24 pin ATX supplies?

RTH2 - Does the RTH stand for, resistor thermal?



C_hegge,

I'd replace the teapo.

Your dislike for Teapo products proceeds you. I have read more than one thread that you have posted in that reflected this. I had read so much bad about them that I figured this one was bad without physical deformity. I was very surprised when it read good on my ESR tester. I will probably change it out along with all the others but I will hang onto to it for testing purposes.

[goodpsusearch]

Re: Antec "Stupid" Power rebuild

Goodpsusearch,

Thanks for this link. I have started reading through it and I noticed that you had ran across a bi-polar capacitor. Is that a common occurance on Antec "Smartpower" or was that because those were older pre-24 pin ATX supplies?

Some models have a bipolar cap placed on the secondary part of psu. If you search the forum you will find more references to it and if I remember correct someone used a polar cap in place of the bi-polar.. Check the original caps of your Antec just to make sure.

Goodpsusearch,

RTH2 - Does the RTH stand for, resistor thermal?

Yes

Your dislike for Teapo products proceeds you. I have read more than one thread that you have posted in that reflected this. I had read so much bad about them that I figured this one was bad without physical deformity. I was very surprised when it read good on my ESR tester. I will probably change it out along with all the others but I will hang onto to it for testing purposes.

Me, sometimes I recap with used Teapo, if I make sure they stay cool.

[c_hegge]

Re: Antec "Stupid" Power rebuild

^

[momaka]

Re: Antec "Stupid" Power rebuild

The small caps should also be replaced. They can cause either annoying high pitched squealing, or worse - a 5vsb overshoot

Indeed.
In fact, given the PCB discoloration on that power supply, I am betting the 5VSB has already started to go out of control. These power supplies use an older 2-transistor design for the 5VSB, which isn't all that great because the reliability of this circuit depends on a small electrolytic cap - usually 10 uF, 22 uF, or 47 uF rated at 25 to 50V. When this cap fails, the 5VSB overshoots. So it's imperative to replace that cap. Or better yet, do an "everell DM311 mod" if you have experience with building some circuits.
(more can be found here:
https://www.badcaps.net/forum/showthread.php?t=8403)

I think the critical cap in your power supply is either one of the caps in this picture:
https://www.badcaps.net/forum/attach...2&d=1347829503
or this picture:
https://www.badcaps.net/forum/attach...9&d=1347829503
Not 100% sure which one, so may as well replace all 3. Other than that, the power supply looks good.

[c_hegge]

Re: Antec "Stupid" Power rebuild

On the SP-xxx, it's the circled one (a 22uF 50V), but still replace all of the small caps.

[goodpsusearch]

Re: Antec "Stupid" Power rebuild

@c_hegge, http://9gag.com/gag/5391740

[LDSisHere]

Re: Antec "Stupid" Power rebuild

Indeed.
In fact, given the PCB discoloration on that power supply, I am betting the 5VSB has already started to go out of control. These power supplies use an older 2-transistor design for the 5VSB, which isn't all that great because the reliability of this circuit depends on a small electrolytic cap - usually 10 uF, 22 uF, or 47 uF rated at 25 to 50V. When this cap fails, the 5VSB overshoots. So it's imperative to replace that cap. Or better yet, do an "everell DM311 mod" if you have experience with building some circuits.
(more can be found here:
https://www.badcaps.net/forum/showthread.php?t=8403)

That looks like something I may want to do in the future since I can etch PCB. I am only hooking it to an old P4 AGP board for now and I have way too many other projects going. The cap C_Hegge circled is a 22uF 50V. I have not had time to remove it but I did clamp my Blue ESR tester to it an I got an open reading. I will pull it as soon as I have time and see what it really reads. The R15 resistor seems to be fine. I also tested the transistor on the other side of the heatsink from the circled cap for shorts but it was not shorted. I am still going to poke around and check a few more things when I get time.

I was able to pull apart my son's supply, but it was already dark so please excuse the poor quality again. About all I can say is that there in nothing popped or burnt looking. I do not recognize the cap makers so I figure that is a bad sign, but I have not known that it mattered for very long. I am not posting the brand, as I am curious if anyone can recognize it by the guts.

Thanks,
Lloyd

[LDSisHere]

Re: Antec "Stupid" Power rebuild

On the SP-xxx, it's the circled one (a 22uF 50V), but still replace all of the small caps.

After work I was able to pull this cap to test it. It was bad in both ESR and capacitance. I am assuming that I should use the same value for a replacement. Thanks everyone, for taking the time to help me out with this rebuild.

[momaka]

Re: Antec "Stupid" Power rebuild

After work I was able to pull this cap to test it. It was bad in both ESR and capacitance. I am assuming that I should use the same value for a replacement.

Yes keep the capacitance the same and the voltage same or higher.

[retiredcaps]

Re: Antec "Stupid" Power rebuild

because the reliability of this circuit depends on a small electrolytic cap - usually 10 uF, 22 uF, or 47 uF rated at 25 to 50V. When this cap fails, the 5VSB overshoots.

My friend's Intel socket 775 motherboard paid the price due to an Antec power supply and the above cap reaching 13V DC by the time I got it for testing.

He knew something was wrong for months as the power supply squealed, but kept using it until the entire computer died.

I fixed his Antec power supply and it is still going good, but the Intel motherboard has been sitting in my basement for about 18 months now.