memory/PSU problem

[RobinsonCT]

Hello, hopefully someone here can help me out. Yesterday I tried to install some additional memory in my computer, and afterwards when I tried turning it on, nothing happened. No beeps, no fans, no lights, nothing. The only thing that did happen was the LED on the motherboard came on. I tried removing the new RAM, but it didn't make a difference, and neither did rearranging the memory chips. I'm nearly certain that I was seating the chips correctly, and I tried multiple times. Anyway, I did some research that indicated the problem may be my PSU, so I got my hands on a power supply unit tester. When I plugged that into the motherboard power (24pin), all the lights (+5V, +3.3V, -12V, PG, +12V, +5VSB) came on except for the -5V light. Furthermore, when I switched on the PSU when it was connected to the tester instead of the motherboard, all the case lights and fans came on (except the CPU fan, which I guess is powered through the motherboard). I tried plugging the 24pin back into the motherboard, thinking that maybe i had just bumped it when I was installing the memory, but no change. What do you all think the issue is? Does the dark -5V light mean that the problem is the PSU, or do the lights and fans coming on during the test mean that the problem is the motherboard?

Some details about my computer: I have an ASUS P5NSLI motherboard, Core 2 Duo e6600 2.4gHz processor, and nVidia 8800 GTS 320MB video card. The computer came with 2x 1GB DDR2 800MHz Memory, and I was installing 2 more 1GB DDR2's (same specs, different maker). Its a 500 watt PSU, but I think it was just the standard model that came with the case (I had the computer custom built nearly 4 years ago, so I don't know for sure).

Thanks so much!

[stroyal]

Welcome to TechIMO!

Those testers are practical useless, you could get the same level of test with a volt meter.

They don't test load, and that what you need, for a full test.

I'm not sure how you had it hooked up. so I don't know what your test proved, if anything.
Trouble shooting dose not involve those methods. How did the case lights come on if the power supply was connected to the tester????

First, many newer power supplies don't even have -5volt, did you check, your power supply label?


If you have nothing with the old memory alone, and checked everything is plugged in correct, you have to go to trouble shooting.

Start with minimum configuration
Motherboard, power supply, video card, monitor, CPU, 1 stick of memory,and keyboard.

To do further tests, you need spare parts, or another working computer to try your parts in.
You can also take your minimum parts to most local shops, where they can test them in another motherboard.
Then it is a case of trying your parts in a working computer, or try known working parts in your computer.

If all your parts check out, one way or the other, it is a bad motherboard., or if they are all new parts there is still the small possibility of incompatibility, mostly with memory.(mostly laptops, still have memory compatibility problems).


Is it real dry, where you are, with a lot a static electricity?
If it is, did you ground yourself, when installing the memory?
I know the the static electricity in my house today, could blow a computer circuit to smithereens.

This will test the memory, if you can boot, or have access to another computer.
Memtest86+ - Advanced Memory Diagnostic Tool.

If you have more questions, don't hesitate to ask.
I don't want to get too deep, as most just go away, when they find, there is no east answer, or fix.

[JPMiller]

What is the brand of the PSU?
What is the +12V Amperage?
4 years is the average life expectancy for MANY electronics, so failed parts will become more common as you go...
Just dont sink TOO much money into old tech....
You may want to buy something that can carry over into a new custom build in a year or 2