System fans don't power down when using FSP Booster X3

[Lavacon]

My buddy just got an ABIT IP35 Pro Mobo and intel e4500 cpu.
He is using an Old 430 watt thermaltake psu and an FSP Booster x3 supplement psu for his video card (Geforce 7950)
When the system powers down, everything but the fans and the FSP unit power down. If we take the FSP off the system everything powers down fine...The FSP unit worked fine on a setup that included an OCZ 520w psu,8800gts,nforce 570 mobo, e6600 cpu.... Any thoughts on what may be causing this issue? Main psu not working right? FSP unit broken????

Thanks for looking

 

[chookman]

Im not sure if that PSU has it or not... but there have been a few released recently that actually continue running the fans in the system for sometime after power off to get the system back to a specified temperature... do the fans ever turn off? or have you not left it for long enough to find out?

 

[Lavacon]

Well I tried my Pc P&C 750 with the booster and its the same problem...

hmmm

Temps are off a fresh boot, so all should be cold...

Grounding problem in the case perhaps??? hmm

 

[Lavacon]

Any ideas???

Bumparu

 

[bob8701]

1. The booster *3 psu is not control by motherboard, so it stay on even the pc is turn off.
2. if the fan is connected on molex connector not on the motheroard, it may stay on since pci express 12 volt and molex 12 volt share same rail.(not 100% sure)

 

[Lavacon]

Well, that Kinda makes sence, I cant imagine that the old thermaltake psu in that system has multiple 12v rails, and would also explain why my PC P&P silencer had the same problem since it has a single 12v rail as well...

 

[Lavacon]

Can anyone second this information about the 12v rails being the issue here??

 

[bob8701]

you can test the problem by plug the fan to the motherboard or even better, you can get a DVM and measure the resistane between the connectors, and please let us know the results.

 

[ZozZoz]

i don't think the rails have anything to do with this.

 

[bob8701]

can you give more detail about your answer?

 

[Lavacon]

I learned of another detail about this problem recently. It appears that that the fan in the psu still runs after the system is powered down and the psu is unplugged. It seems as if the X3 unit is feeding power back into the whole system.

Good times

 

[darkstar782]

Yeah the X3 is crap tbh, have one myself.

It is SUPPOSED to be switched on/off by a +5v signal from the main PSU (this is why it needs a molex connector plugged into it).

However it seems it is able to power the main PSU via the Gfx card or the molex connector and ends up keeping itself switched on... I assume that all the rails on the main PSU are linked, and there is some 12v-5v drop down meaning it is still outputting +5v and switching on the X3?

I also found that with the X3, 3 8800GTXs in tri-sli, and a PC P&C 1kW as the main PSU, I got the "nvidia card is not recieving sufficient power" message, while I DON'T get that message without it.

It now sits on a shelf doing nothing

 

[Lavacon]

Ebay that POS...lol
FSP is sending me an adapter to connect it to a 5v cable instead of a 12v.. if that doesnt work Its being sent in... good times