SATA HDD POWER MAKES PC HANG

[angeloslev]

I have an old DFI 661FX-MLV MB (yeah, I know, old stuff, but it's for a 2nd pc for my country house).
It used to have a SATA HDD, but I lent it to someone and he burned it.
So I bought a new WD 500 GB SATA2 HDD, SATA of course.
Now my problem is that as soon as I connect the HDD's power to the PSU (through a molex-SATA adapter, as before) the pc refuses to even boot. In fact it starts and then keeps restarting, without even going to BIOS.
I'm at a loss since nothing else was changed.
The SATA data cable itself is irrelevant. Whether I connect it or not, makes no difference. But as soon as I connect the power...poof.
Any ideas?

 

[angeloslev]

I forgot to mention that both HDD and molex-sata adaptor are new and also that they were working on another MB some hours ago, also with the same PSU.

 

[John_VanKirk]

Hi there,

Sounds like the PSU voltage drops or becomes unstable when you connect the new HDD to it, and the PWR Good signal causes the CPU to restart the computer.

The Molex 4 pin to SATA power 15 pin adapter should be examined carefully. Check to see the 3.3V leads are not connected to a power line, and that the red 5V line goes to the center 5V SATA connectors. Also take a magnified look at the HDD SATA power connector. There are 15 pins in the SATA power connector, 3 pins for 3.3V, 3 pins for Gnd, 3 pins for 5 V, 3 pins for Gnd, 3 pins for 12V. Should be like the image here. If any are shorted or bent so they short out when connected, that could drop the PSU voltage enough to cause your system to reboot. You could also see some black staining where they might touch

.

The pins are very close together. If you don't see any obvious problem, plug a different SATA drive if you have one, into it to see if that is OK. You don't have to plug the data cable in at all.

That way you will know if it's the adapter, or new HDD that's the problem.

 

[angeloslev]

Thanks for taking the time to reply.
Problem is, that both the HDD and the PSU (together with the same molex-sata adapter) were working just fine on another motherboard (and still do, I just tried). It's only with this m/b that I get that problem (can't use the other one for other reasons).
All cables etc look fine (although I can't be sure) and as they are working on the other m/b, I must assume that the problem is not there.
Weird thing is that this same m/b used to work with a SATA HDD and the same adapter (albeit a couple of yrs ago was the last time I checked), with no problem.

 

[John_VanKirk]

Thanks for taking the time to reply.
Problem is, that both the HDD and the PSU (together with the same molex-sata adapter) were working just fine on another motherboard (and still do, I just tried). It's only with this m/b that I get that problem (can't use the other one for other reasons).
All cables etc look fine (although I can't be sure) and as they are working on the other m/b, I must assume that the problem is not there.
Weird thing is that this same m/b used to work with a SATA HDD and the same adapter (albeit a couple of yrs ago was the last time I checked), with no problem.

If it works on another PSU/MB, then in all probability both are OK.

What model and size PSU are you using?

Very unusual but possibly the additional 20 Watts startup used by the HDD has dropped the voltage on one of the rails causing the Pwr Good signal to drop and to reboot the system.

Try connecting the molex end of the adapter to a different rail (cable from the PSU) and see if that permits it to start up OK. One other thing to try is to disconnect the power to any other secondard HDDs, a SLI Video Card or DVD burner, then see if it will boot up OK. That would tell you if the PSU is barely marginal to handle the new device.

 

[angeloslev]

It's an old 300W PSU (with no SATA power supplies, obviously). I tried disconnecting everything but the GPU and the problem persists. Also tried all available molex supplies of the PSU with the same result (all of them work fine when I connect them to a regular IDE/molex power DVD).
Remember, the SAME power supply, with the SAME molex adapter with the SAME hard disk are working fine when connected to a different motherboard. That's what bugs me.
The reason i don't use the other M/B is because it has a PCI-E GPU slot and I have no PCI GPU available atm, whereas this one has an old AGP slot. Don't know if that makes any difference.

(I know it's a strange problem and I don't rly expect to find a solution. Just in case, though....).