Question : Problem: New PSU won't boot PC

I decided to replace the PSU in my PC for a quieter model.  I already have a QTechnology Ultra-Quiet ATX PSU (460W) but it has an annoying high-pitched whine that I’ve been unable to get rid off.  I’m replacing it with a SilentMaxx Fanless-Pro (503W) PSU – almost 400 USD of power supply!

I’m now on my second unit is as many days because I couldn’t get the first one to work. I can't believe there would be two faulty units though.

I'm back on the QTechnology PSU (and everything’s working fine) but I tried every combination of connections with the SilentMaxx and couldn't get it to boot my PC.

All that happens with the SilentMaxx is that when I press the power switch the PSU fan spins up and the processor fan (Zalman CNPS6500B) spins but the PC doesn't boot (I don’t hear the familiar chatter of the hard disk). As soon as I remove my finger from the power button the fans spin down.

The motherboard is a Jetway 845E and has three power connectors. A 20-pin ATX power supply connector, a 4 pin ATX 12v power connector and a 6 pin ATX P9 power connector (the QTechnology PSU doesn't have this - although I've tried the SilentMaxx with and without this to no avail).   There’s also a fan monitor cable…

The PC needs power leads for two Hard Drives, a floppy, a CD and DVD drive as well as a removable drive cage - but even with just the motherboard connections and only just one Hard Drive, the PC doesn’t boot.

I've also tried the PSU in all three modes (no fan, full fan, etc.) but it still doesn't work.

SilentMaxx tech support is closed from today until 4 Jan.  Any suggestions?   :-)

The specs for the two PSU’s can be viewed here http://www.quietpc.com/uk/psu.php

Malcolm

Answer : Problem: New PSU won't boot PC

Silentmaxx    12 volt = 19 amps
Qtechnology  12 volt = 29 amps

Do you have a monster machine requiring more than 19 amps ?

Remember fanless PSU may require additional case fan to remove hot air from case !

Many Mobos has a CPU fan sensor . If no fan is sensed the MOBO will ask the PSU to power off.
Cpu fan in appropriate socket ?

Are you using the same connectors/sockets with the 2 PSU's ?

Both PSU' s have the ability to have the FAN speed monitored by Mobo.