No post, nothing at all. PSU issue?

S

Spare-Flair

Supreme [H]ardness
Joined
Apr 4, 2003
Messages
7,471
Built a system for a friend and I insisted many times that he should get a new PSU but he said "it was okay" and re-use a 550W Antec Trio.

I just want to confirm if this is a PSU issue. If we can get the computer to turn on, it will be fine but if he shuts down, often he cannot get the computer to turn back on. There will be no response at all, the PSU fan won't even spin. The power on pins won't spark, etc.

As long as the two pins are bridged on the 24 pin connector, it should have some kind of response should it? I've seen PSUs turn on briefly and ground out when they find a fault in the system but the PSU won't turn on at all, as if there was no power at all (yes, did check if it was plugged in).

Is the power draw at power on significant? Is there a "hump" it has to get over for the PSU to be able to basically "turn over?" System is a 2500K on Gigabyte H67 chipset with an ASUS 2GB 5870 Matrix with 4 mechanical drives and an SSD. I'm pretty sure it's the PSU, but just wanted to make sure that this isn't something to do with the motherboard.
 
Have you made sure you plugged in both the 24 pin and the 8pin on the motherboard? If both of those are plugged in, then you should have sufficient power. That PSU should be able to run that system. From AMD: "500 Watt or greater power supply with two 75W 6-pin PCI Express® power connectors recommended ." From reviews I have seen total system power for a single HD 5870 was around 350W. The only thing that might be iffy is if the PCIe cables are all on the same rail as the motherboard.
 
If the fan won't even spin up if you try and jump it, the PSU is dead.
 
Last edited:
Nothing. But the green wire is not going to "spark" either. I think he thinks you're jumping it and then shorting live wires to see if the PSU works. ;)
 
jonnyGURU said:
Nothing. But the green wire is not going to "spark" either. I think he thinks you're jumping it and then shorting live wires to see if the PSU works. ;)
Click to expand...

No, I'm not that crazy. Just jumping the power header on the motherboard with a screwdriver.

The last time this happened, he changed power bars and the computer turned on again. Then he shutdown after 12 hours and now the computer won't turn on again, even if he tries different sockets.
 
Turned out to be a bad stick of ram. So strange. One bad stick caused the system to not power on at all.
 
Ooohhhh.... you were talking about the two pins on the motherboard.

We were thinking you were talking about testing the power supply, sans the motherboard, by jumping the power on pin on the power supply with a ground:

http://www.jonnyguru.com/modules.php?name=NDArticles&op=Story&ndar_id=25

I bet if you knew that trick before you started, you would've figured out a long time ago that the PSU is fine. ;)

It's not unusual for one component installed in the PC to prevent power on. If that part has a short on it, it's still part of the circuit and can cause the whole PC to not start up.
 
You must log in or register to reply here.
Back
Top