Antec 350 Recap Epic Fail

[bigbeark]

Re: Antec 350 Recap Epic Fail

I did the exact same thing with an original version 300W or 350W Antec SmartPower, which also used high voltage MOSFETs, but after I unplugged the AC and plugged it back in (after installing the case top), the PSU worked normally. Neither fuse blew (this design had 2).

I haven't had too many MOSFETs fail on me, but every one that did had a short between the gate pin and the other pins, regardless of which direction the meter leads were connected.

I've read that the heatsink is connected to 170VDC in order to provide shielding from RF and to make it safer than connecting it directly to ground because sometimes there's no earth ground. The only grounded heatsinks I've seen were in the low voltage section of the PSU, namely in FSP (Fortron-Source Power) brand products.

Thanks for this reply, I think I can safely assume that the primary heatsinks on this PSU are "live" when the PSU is plugged in, courtesy of the bridge rectifier, which allows current to flow between legs of the rectifier. Since the negative leg of the rectifier is connected to the same line as the heatsink ( visible on the back of the PCB), current will flow to the heatsink whenever the PSU is plugged in.

Or, to simplify, never plug the PSU in with the top off!

[Per Hansson]

Re: Antec 350 Recap Epic Fail

Because the switch is off, that does NOT mean there is no voltage in the circuits. It likely was a N-GND short, or possibly they messed up big time and put the switch on the neutral, so the components are always live (on hot wire)

Imagine your finger conducting the primary heatsink and the case... Yeah that happened to me... It was an Antec Smartpower 450 and the switch was at the off position but it was connected to neutral..

Isn't the switch mandated to cut both Live and Neutral?
Here in Sweden and the majority of Europe the Schuko plug is used which is not polarized, meaning our AC plugs go in both ways, so we can flip the live and neutral in any equipment.

[goodpsusearch]

Re: Antec 350 Recap Epic Fail

Isn't the switch mandated to cut both Live and Neutral?
Here in Sweden and the majority of Europe the Schuko plug is used which is not polarized, meaning our AC plugs go in both ways, so we can flip the live and neutral in any equipment.

Same here. The problem is that the switch most psus have only cuts 1 of the 2 lines.

[Behemot]

Re: Antec 350 Recap Epic Fail

I also worked as conductor once, between two heatsinks of one Enhance made Chieftec. BOTH, primary AND secondary are live, so fortunatelly there has been just like 160 V between them. Strange is, SP and my Chieftec are made by different manufacturers (CWT vs. Enhance) and yet they both use the same stupid topology?

As for grounding, on every other PSU I have seen so far I am almost sure the heatsinks were grounded. If rubber pads break, it shorts the PSU and it does not power on. Not that I have ever seen damaged pads between package and heatsink…

[Pentium4]

Re: Antec 350 Recap Epic Fail

I'm recapping a similar SmartPower and want to replace the Fuhjyyu input caps, which I'm not as knowledgeable on. I have some Elite caps (which I consider better than Fuhjyyu) that are 820uf 220V. I forgot if increasing the voltage on input caps causes issues or improves it.

[goodpsusearch]

Re: Antec 350 Recap Epic Fail

Elite are crap.

Increasing the input caps voltage doesn't hurt. It could help their endurance.

[Pentium4]

Re: Antec 350 Recap Epic Fail

Elite are crap.

Increasing the input caps voltage doesn't hurt. It could help their endurance.

Thanks for the reply yeah I know they're crap, but wouldn't you trust higher rated Elite over Fuhjyyu?

[goodpsusearch]

Re: Antec 350 Recap Epic Fail

You can try

[lti]

Re: Antec 350 Recap Epic Fail

Why would increasing the voltage rating of a cap hurt anything?

[c_hegge]

Re: Antec 350 Recap Epic Fail

It won't

[Pentium4]

Re: Antec 350 Recap Epic Fail

I don't think it's even worth trying, this thing looks to be in bad shape...It looks a lot darker in person (my phone doesn't take the best pictures) But on the soldering side it looks like a bunch of joints went cold.

[goodpsusearch]

Re: Antec 350 Recap Epic Fail

I always try to fix them to the point that I find there are many parts damaged (transistors, optocouplers, ICs), then I quit.

[everell]

Re: Antec 350 Recap Epic Fail

The dark area looks like it is in the 5VSB area. Hang on to it for just a little longer. I am getting ready to do a post on converting 2 transistor 5VSB to VIPer 22A pwm chip. The conversion is much easier than the DM311 mod. You can use your Antec SP-350 to try this conversion. Here is what the add on board looks like.

[Pentium4]

Re: Antec 350 Recap Epic Fail

The dark area looks like it is in the 5VSB area. Hang on to it for just a little longer. I am getting ready to do a post on converting 2 transistor 5VSB to VIPer 22A pwm chip. The conversion is much easier than the DM311 mod. You can use your Antec SP-350 to try this conversion. Here is what the add on board looks like.

Sweet! Thanks everell. I'll hang on to it. The darkest spot on the entire PCB is on 2 of the PWM controller pins. When it's plugged in it won't boot up but it'll give a high pitched whine. Does that mean there is still life in the 5VSB circuit?

[nickBcap]

Re: Antec 350 Recap Epic Fail

Hi, I have a died Antec Sp-350 that had two swollen capacitors which I removed and bought smaller same value capacitors for. The original swollen capacitors are 8mm x 16mm and the replacements I bought, without thinking about the size are 8mm x 12mm.
Should I buy the correct sizes?

[retiredcaps]

Re: Antec 350 Recap Epic Fail

Should I buy the correct sizes?

As long as the replacement caps' ESR and ripple are near equivalent to the originals, size won't matter.

[Behemot]

Re: Antec 350 Recap Epic Fail

But usually smaller size means lower capacitance.

[ben7]

Re: Antec 350 Recap Epic Fail

But usually smaller size means lower capacitance.

Not quite always.

Some capacitor series are made to be smaller and have the same capacitance.
But yes, generally, smaller size capacitors have a lower capacitance and/or voltage rating.

[nickBcap]

Re: Antec 350 Recap Epic Fail

Here is the two capacitors for comparison.

I want to replace the larger capacitor with the smaller capacitor if I can. From what I have learned the Nichinon cap will be a better quality cap then the Capxon capacitor, but I did not have this in mind when I bought them, I bought the smaller capacitors without reading the auction properly.

[Shocker]

Re: Antec 350 Recap Epic Fail

What series are the caps???