I bought the FSP Zen, but the motherboard doesn't turn on

PSUs: The source of DC power for all components in the PC & often a big noise source.

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I bought the FSP Zen, but the motherboard doesn't turn on

Post by lucibalaj » Sun Jul 08, 2007 1:41 am


I have a very simple system (see below the configuration) and I bought a Fortron Zen 300W. However, the motherboard is not turning on (only the cpu cooler and the case fan are turning on). What should I do? Is my motherboard not supprted by Zen? Should I return the PSU? Thanks!

- ASUS A7N8X motherboard
- Samsung 160 Gb HDD
- 1 DVD
- Passive NVidia GeForce 5200 graphic card
- 712 MB RAM
- AMD Burton 2500+
- Zalman CNPS 7000-AlCu LED cpu cooler
- Creative SB audio card
- Antec Sonata II case

Thank you very much,
Best regards,

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Post by Bluefront » Sun Jul 08, 2007 2:36 am

Not sure about your particular MB.....but these sorts of start-up problems on high-efficiency power supplies are somewhat common. Try hooking up something that draws slightly more current....like another hard drive,or a few more fans. Maybe even a 12v light.

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Post by Techno Pride » Sun Jul 08, 2007 3:16 am

What Bluefront said, and probably a bad PSU too.

In any case, the Zen300 is a bad choice for that setup, since the motherboard draws +5v for the processor. The voltage regulation on recent PSUs favour heavy +12v loads.

For that AXP setup, the +5v rail voltage will be too low, and the +12v rail too high.

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is there a solution

Post by lucibalaj » Sun Jul 08, 2007 4:00 am


is there a solution to make the system work?
since i am not so expert in this can you please tell me step by step what i should do?

thank you,

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Post by alleycat8675309 » Sun Jul 08, 2007 8:57 am

See this thread:

So you've been testing with everything plugged in? As some others have suggested, try plugging in another 1 or 2 fans. Otherwise buy a psu tester like this: http://www.startech.com/Product/ItemDet ... EST20&c=US

It may be possible for DIYers to mod the device to use like in the examples discussed in the article above.

I have a similar setup but also with a wireless-G card, no sound card. I have a Zen 400 which requires a minimum starting load of 0.2 amps on the 12v line. I recall that the Silverstone Nightjar psu requires a minimum starting load of 0.5 amps and the Zen 300 is 1.0 amps. I specificially looked around for info on the minimum starting loads after experiencing some problems like you have.

I had similar problems with my Antec Neo430 psu (1.0 amp minimum starting load). It would not start when just connected to the motherboard. With the psu tester attached, the psu would start and the fan would sping. With all components attached it would start too, but I didn't try it at the time until after I read the above article.

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answer from ASUS

Post by lucibalaj » Mon Jul 09, 2007 12:08 am


Thank you for your reply. This is the answer I've received from ASUS suport:

Sir, due to the a7n8x is a rather old board,
you need use a bit older spec PSU,
please contact your PSU vendor and purchase a ATX 1.3 spec PSU for it.

What should I do? I have to change the PSU, after I payed so much money?

Thank you,

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Post by burebista » Mon Jul 09, 2007 12:44 am

At her time my A7N8X works flawless with S-12 430.

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Post by |Romeo| » Mon Jul 09, 2007 9:17 am

Since I power an A7n8x from a 300W Zen without problems, the two are not entirely incompatible, so to ask the obvious question, have you tried the Zen in another system?

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Post by lucibalaj » Mon Jul 09, 2007 10:01 am

no, i didn't try it on another system. but since the cpu cooler (zalman) and the antec sonata fan are working, i tought it's no problem.

should i try it on another system?

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Post by cloneman » Mon Jul 09, 2007 11:24 am

You should try it another system. My zen won't power up my Via C3 733Mhz, but it powers up my p4 fine.

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it works!

Post by lucibalaj » Sat Jul 14, 2007 12:38 am


i have added a DVD rom in addition and now the computer boots up.

Best regards,

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