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Dead Mobo?

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3 replies to this topic

#1 jwhixen


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Posted 13 May 2008 - 10:50 PM

I have trolled various sites and this one seems to be the most knowledgable. I have a computer here that was built about 5 years ago. It has an Intel ?4000782? mother board and not sure of the chip. As I noted before I checked other postings and have checked the PSU it outputs all the correct voltages on the 20pin and the 4 pin when i jump the "green" to the "black" on the 20 but when installed connected to the motherboard it does not output anything. The power button on the front does not work and the only light to come on is a little green led near the 2nd from the top pci slot, but no power at the HDD and the fans do not work. I am wondering how do I find out definetely that it is the Motherboard? I have used the PSU in another computer works fine but using another PSU w/ defective Mobo has no effect. Is there a way to modify the Mobo or do I have to get a totally new Mobo?

Thanks in advance, Jimmy :thumbsup:

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#2 smurfgod


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Posted 14 May 2008 - 11:06 AM

You say the power on (case) button doesn't work, have you tried "hotwiring" it? may just be something as simple as your power on switch/wiring got busted. I forget exactly what wires are needed to do it. If nobody else tells you by the time i get back from the store i'll search it out.


Edited by smurfgod, 14 May 2008 - 11:14 AM.

#3 Sneakycyber


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Posted 15 May 2008 - 03:22 PM

Switches seldom go bad, personally I have never seen a bad one. Testing your switch would be the best way to avoid any unwanted contact with the motherboard. Be sure to unplug your computers power supply from the electrical outlet before opening the case. After opening the case remove the power switch plug that connects to your motherboard (with out knowing the computer specifics I can't tell you which one it will be) it will be grouped together with a few other wires routing to the front of the case and to the switch it self. After unplugging the wires using a voltmeter set to continuity test touch the black lead to one wire and the red lead to the other wire, press the switch the tester should beep. If your tester does not have continuity test use the Ohm setting and the numbers should almost zero out depending on the ohm setting you have it set to. If nothing happens replace the case or the switch with a new one. The other thread has links to suitable switches you can use. There are other options to test the motherboard but without knowing the exact model of motherboard and the location of good pictures there is no safe way to describe how to short the PS/On contacts. Shorting the wrong ones could damage the motherboard and possibly shock you. IMO the motherboard is bad and needs replaced but it should be tested first.

Chad Mockensturm 

Systems and Network Engineer

Certified CompTia Network +, A +

#4 xXAlphaXx


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Posted 17 May 2008 - 10:03 AM

Following up on what Sneakycyber said, if its a bad switch their pins on the motherboard in witch you touch two pins together with a metal object it will turn on assuming the motherboard is not defective.

Good Luck.
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