Please help me before I throw this Dimension off my roof

DougEFresh

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I have a Dell Dimension 8400 that will not turn on. I tested multiple power sources and power cables, made sure the psu was on 115. I replaced the CPU, motherboard, front panel switch, I/O control panel and cable, and the cpu fan and hood. I shorted the P1 connector which turned on the psu and tested it with a voltage meter and it read 5 and 12 v as it should. At this point I've replaced or tested everything in this machine that would prevent it from turning it and still nothing. Will a bad video card prevent it from turning on? WHAT IS WRONG WITH THIS PIECE OF ***!?!!?!!?!!
 

Keiki646

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Make sure that the right front Panel switches are in the right place. Make sure the memory is in the slots correctly.
Make sure the PSU switch is off and unplug the power cord when doing all of this.
How long did you have this Dell and what year model of the Dimension.
 

DougEFresh

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It is a Dell Dimension 8400 I'm fixing for a friend that said he wanted windows reloaded. I vacuumed the inside of it before I tried turning it on. The ram is in the right slots. There is no switch for the PSU you just plug it in. I know the risks or static and take proper precaution when working inside it.
 

Keiki646

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So that is a Pentium 4 CPU Computer, Can you make sure that the Power 20+4 pin is in and the 4pin power is in
note that even with a bad video card the computer still can turn on
 

Keiki646

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What do you mean by replace??? Please be more in details
 

Keiki646

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You you have replace the CPU motherboard and heatsink and Fan
 


Then why the hell did you vacuum the inside of the case? That creates a HUGE static charge
 


There is a possibility of the replacement mobo being bad but the light on it turns on and is green. Most mobos from the Pentium 4+ (maybe before as well) had a green light on the mobo as well as a red light if there was any problems. So it seems the mobo might be fine.

It almost sounds like there is a short. Either the power button doesn't work or something is shorting it out like a mobo screw or even expansion slot card/cover.

I would try two things. One is to try to jump the power button pins directly instead of the button and as well make sure all the pins are properly going to where they need to.

Second is try it outside of the case. See if it is a short.
 
The power button itself is connected via two pins on the mobo, normally in the lower right hand corner of it. When you press the button, it closes the loop which allows for power to start flowing. If you find thos pins it is connected to and use a wire or jumper block to make them contact, it will do the same as the power button does.

As for trying it outside of the case, I mean by getting some ESD safe materials and putting the components outside of the case itself. If you set it up that way and it works then its possible a short is causing the problem such as a screw for the motherboard or one of the plates for the expansion slots.
 

DougEFresh

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The power button is connected to a I/O control panel (see link 2), and from there a ribbon cable goes to the motherboard (see link 1). Take a look at link 3 to see where it connects to the motherboard via front panel connector. So which pins do I short?

As for option 2, I have an anti static mat and I've taken components out and tested everything. What I need to know is what is the bare essentials to get this powered up. From there I can troubleshoot if somethings wrong but I can't do anything but guess of whats wrong until it starts.
 
G

Guest

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As long as you have grounded yourself by grounding yourself to the pc case whilst its plugged to the mains turned off at the socket, you can hoover or use a paint brush gently to clean out a PC case.

I have spent 15 years with electrical components and PC's and have to this date never ever caused a failure due to static discharge because I ground myself before starting work.

http://en.wikipedia.org/wiki/Static_electricity


 

doive1231

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Hi, it sounds like it must be due to the front panel connector. You say that a green light comes on. There is a light diagnostics section in the link you provided from Dell - goto Advanced Troubleshooting, Light diagnostics.

But this front panel. On other computers' motherboards & cases you must have the power switch connected, it's often a fiddly little lead/connector that holds the key to the whole PC working because initially, the BIOS is not set to restore power after AC off i.e switching off the computer. If you can, just remove all the other fiddly leads and just try this one. A lead connected the wrong way could short the PC (when I first started building PCs, I often had smoke coming from these leads because I put them round the wrong way).

If the Dell case does not have these leads then I don't know what's up. Sorry.
 

DougEFresh

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The Dell doesn't have these leads (see my last post to see how it is set up). The green led is on the motherboard. The light diagnostic section is for the set of 4 led lights on the back connectors, these don't light up at all.