Antec Smart Power SL-400 5vsb mod using VIPer 22A

[everell]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

I recently acquired a Smart Power 430. Don't like that 2 transistor 5vsb circuit, so made a mod using the NCP1216 pwm chip. The original 5vsb circuit is the same as the Antec SL series, but the component numbers on the pc board are not the same. So I took a copy of my original SL400 5vsb circuit drawing, and changed the component numbers to match the TruePower 430. Next I made of drawing of the modified circuit. Wired it up, turned it on, and BANG! See picture of damage to switching FET transistor! Some troubleshooting revealed that I had overlooked the 1 ohm resistor between FET source and ground. This power supply was dead when I first got it, and apparently the problem was a blown 5vsb circuit. So the source to ground resistor was still open.

Replaced the FET, NCP 1216, open resistor, and powered up again. This time the 5vsb was working fine.

Voltage readings on this power supply:
12.31v
5.07v
3.342v
5.13v 5vsb

Didn't want to let this one get away because it has two nice Rubycon capacitors on the primary side. Most of the other capacitors are the "F" brand and still need to be changed. The 5vsb mod was a success.

[LDSisHere]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

I am glad to see you have had a chance to do some more experimenting with the NCP1216. Although I have not yet had a chance, I intend to modify one or both SP's that started a thread on a while back ago.

It really sucks when you go to power something up after a repair/mod and it goes bang. It is bad enough when it just does not work, but when it causes you too need more parts, time and effort it can be frustrating. I have a bad habit of overlooking those low ohm resistors myself, especially if they are covered in heat shrink tubing. It is great that you were able to get it all working again, probably better than new in this case.

[ben7]

Re: Antec Smart Power SL-400 5vsb mod using VIPer 22A

It really sucks when you go to power something up after a repair/mod and it goes bang. It is bad enough when it just does not work, but when it causes you too need more parts, time and effort it can be frustrating. I have a bad habit of overlooking those low ohm resistors myself, especially if they are covered in heat shrink tubing. It is great that you were able to get it all working again, probably better than new in this case.

And .... that is why I always get at least 2 of a certain part, one extra in case of a mess up ... those small smd chips can be fragile.