Recapping Antec SmartPower SP350 and SP400

[Toasty]

Re: Recapping Antec SmartPower SP350 and SP400

Picture from this thread:

https://www.badcaps.net/forum/showthread.php?t=31149


Picture: https://www.badcaps.net/forum/attach...chmentid=69689


While it -has- the fan controller on it, it's not its' only function. It does the PS_ON line and voltage Supervisor too.

One of the 2 smaller chips (IIRC...?) do the PS_ON. WT7518D

notes, notes, notes... Ah-ha!

Desolder just pin 8 (Vcc) of the 8-pin vertical chip and see if it will switch on. Make sure it's not touching the pad.

In the picture it's the one adjacent to the yellow cap and pin 8 is the bottom left.

** No need to remove the board to do this.

T

[cno]

Re: Recapping Antec SmartPower SP350 and SP400

Yes, it does and I have pix:

http://www.vintageelectronics.ca/gal...ty/AntecSP400/

[eccerr0r]

Re: Recapping Antec SmartPower SP350 and SP400

The SP400 uses a voltage doubler when used on 120VAC.

I fried my SP400's switcher chip when my 5VSB blew, so I had to replace it too.

[Toasty]

Re: Recapping Antec SmartPower SP350 and SP400

Updated above post with info and datasheet.

T

[momaka]

Re: Recapping Antec SmartPower SP350 and SP400

There is something I do not understand: when I put the AC voltmeter across the inner pins of the rectifier bridge, it reads 120V give or take a few. But when I switch it over to DC and put it across the outer pins, it reads 350V give or take a few. Should there not be 120*1.41=160V only there? The el caps on the high side are 820uF * 200V, so 350 would be disastrous.

No, that's normal.

As eccerr0r mentioned, there is a voltage doubler circuit on the primary side of the PSU: those two 820 uF, 200 V caps are in series, and the voltage doubler puts about 160V across each. So the result is 2 * 160V = 320V. Well, you get more if your line is a little higher.

[cno]

Re: Recapping Antec SmartPower SP350 and SP400

Thank you so much for the tips, Toasty, ecerr0r and momaka! I got the idea and as soon as the soldering station I ordered arrives, will try to disconnect pin 8. Once I pulled apart the wire harness, a few blown up caps cropped up, so will be replacing those as well. Will post back!