Hi Dave. Can i apply the same hacking to an ATX based on fsp3528 chip by using the relevant pins of course (ie pin 13, 14, 15 and 16).
As per fsp3528 here is attached a description of its various pins.
Thanks.

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Yes.looks like the same.chip, pins 13,14,15 are the 3V,5V,12V sense pins to fool the same..

 

Yes.looks like the same.chip, pins 13,14,15 are the 3V,5V,12V sense pins to fool the same..

Thanks a lot for answering...Have i to totally isolate the three pins (cut all the tracks or pull up the pins) before making the modifications? and please what about the short circuit protection is it still here ?
Happy new year.

 

Yes, best to isolate the pins like in my previous diagram, using resistors or presets, pin 16 looks like its an Overcurrent sense pin about 0.7V, all being well it should work ok.

Happy New Year!!

 

Yes, best to isolate the pins like in my previous diagram, using resistors or presets, pin 16 looks like its an Overcurrent sense pin about 0.7V, all being well it should work ok.

Happy New Year!!

In your diagram you have connected the 5v stb to the vcc (pin15) Why?

 

In your diagram you have connected the 5v stb to the vcc (pin15) Why?

The Vcc doesn't have to be connected to 5V stby, as long as the 5V rail for the presets is fixed at 5V, like the stby rail, the chip will regulate ok,

 

I dont think the minus 12 volt rail can deliver much power. It certainly wont match the plus 12 volt rail in current capability.

 

The Vcc doesn't have to be connected to 5V stby, as long as the 5V rail for the presets is fixed at 5V, like the stby rail, the chip will regulate ok,

Tanks for the clarification... But i have an issue : I have cut the track going to pin 4 and soldered a 5v stb wire to that pin. After that and just for testing purpose i powered on the ATX but it shuts down 3 seconds after. When resoldering cutted track and removing the 5v stb wire (return to original situation) it power on correctly??? What may be the problem.
ps : My chip is an ATX 2005Z.

 

Pin 4 is the 5V sense pi, it needs to go to the 5vref pin 11,,or 5v stby pin1,,to maintain a 5v signal,

If its shutting down its sensing over voltage or under voltage...

 

Pin 4 is the 5V sense pi, it needs to go to the 5vref pin 11,,or 5v stby pin1,,to maintain a 5v signal,

If its shutting down its sensing over voltage or under voltage...

Now it is working...Had to connect a load resistor on the 5v rail (5R/10w)...(strange because i had not to do that with another atx psu i have?
By the way i'm using the purple wire of the psu as 5v stb source. Now i'm going to connect the 3.3v preset to see how it's going on. Thanks again for helping.