Hello,
I was given a computer that wouldn't turn on. It's an Emachines model T6412.
Here are the specs:
CPU: AMD Athlon 64 3400+ 2.20GHz, 1600MHz FSB
RAM: 512MB, 128MB used for integrated video
HDD: 200GB
Video: Integrated ATI Radeon Xpress 200 (PCI-Express)
Power Supply: 300 Watts Max
I determined early on that the power supply was bad. With the power supply plugged into the mother board the voltage at +5 VSB (+5 Volts Standby) was only 4.00 Volts. The motherboard was only drawing 60mA on the +5 VSB supply. I unplugged the power supply from everything and loaded it with a 47 ohm resistor and it read 3.8 Volts. That is only a little over 100mA load on a supply that should deliver at least 2 Amps.
Since I was chomping at the bit, I took the power supply out of my computer ( 550 Watts) and put it into the Emachines. While the computer was running I was constantly feeling my power supply to see if it was running hot. It was cool. The only card in a PCI slot was removed.
This is what I found:
1. The first time I pushed the power switch it turned on and was running for about 20 minutes and then it rebooted. I noticed that when the screen went blank, the CPU fan would go full blast for about 2-5 seconds, slow down to the lowest speed, and then the computer would begin to boot up. It was rebooting constantly. I went into "Start Up and Recovery" and unchecked "Automatically Restart" under "System Failure" to see if I could get a BSOD instead of restarting. It still restarted.
2. I noticed that the HDD and the Power LEDs were not lighting up so I turned the computer off and unplugged them. I know I should have investigated further, but I wanted to clean up the hard drive.
3. Sometimes when the computer was turned on, the CPU fan would begin at full blast and the computer wouldn't boot until it slowed down. Sometimes when the power switch was depressed, it may take 20 or more seconds before it would turn on.
4. I was able to stop the computer from rebooting by going into the BIOS under PC Health and disabling the variable speed for the CPU fan. While I was there I noted the CPU temperature. It was 100 degrees F. I also felt the CPU heatsink and it was cool. It hasn't rebooted since.
5. After disabling the CPU variable speed, I noted that the CPU fan runs at slow speed until the screen gets to where it displays "Press F2 for BIOS" and then goes full blast and stays that way until the computer is turned off.
6. I pulled my power supply out and put it back into my computer. My computer wouldn't turn on at first. I hit the power switch and nothing happened for about twenty seconds and then it turned on. My computer has been running great for two days now. I only had that one hiccup, but this is not good.
7. I did some searching on the internet and found out that the power switch, HDD LED, and power LED were all plugged into the wrong pins. I didn't know that my nephew had unplugged them and put them back in wrong. The connector is a 2 X 5 connector. It was just dumb luck that the power switch worked. If this computer had a reset switch it would get plugged in across from the power switch. The power switch was plugged into the pull-up side of the power switch and the pull down side of the reset switch. It looks like both switches have the same input circuitry so I don't think the power switch being in the wrong pins has anything to do with whatever is wrong with the computer.
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This is what I know for sure so far.
1. When the CPU fan variable speed is enabled, the computer restarts constantly. There is no BSOD when this happens.
2. When I put the power supply back in my computer, it acted up at first when I turned it on. It took some time before it turned on. I put this computer together about 4 or 5 years ago and it has never given me any trouble. It has turned on immediately every time.
I don't like the idea of putting my power supply back into the Emachines computer, but I am going to one more time with the power switch, HDD LED and Power LED plugged into the right pins. I will unplug everything that isn't needed to see if if the motherboard will power up without trouble.
Regards,
Ken
Hello,
The recovery disks arrived today and I tested the computer again and decided that the motherboard is bad. I went to the Emachines website to get a replacement. They didn't have one so I emailed tech support to ask if I could get one somewhere else. They responded a couple hours later.
THIS COMPUTER IS STILL UNDER WARRANTY. They want to replace the power suppy first. It will be arriving in 3-5 days. Wow! My nephew never said anything about a warranty. I figured that since he was giving it away, it wasn't under warranty.
Regards,
Ken
Well there's good luck for you - best keep quiet about your nephew's "creative rewiring" though in case they change their mind... ;)
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