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Dell 8400 dead

Hi when i pulled the power supply off 2 of the 4 pins are burned badly is the mb finished recom

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I have a Dell Dimension 8400 Series desktop that is totally dead. Nothing happens when power button is pushed. Of course it is plugged into a live outlet.

Possibly a bad power supply. Could aslo be bad hardware.

Depeding on how save you are with computers, depends on how far you might want to go with this.

But remove everything one at a time and try to start the computer. Until all you have is a motherboard, processor, fan, and power supply hooked up. If you are still not getting any power, try to swap the power supply first. If that doesnt work then either Motherboard or Processor.

Lastly, swap the power cable out to see if its a bad cable.

May 03, 2011 | Dell Dimension 8400 PC Desktop

1 Answer

Can not get computer to power back up no lights on front o rear just little light on mother board have dell 8400

Bad Power Supply, sscorbett.

Usually you have enough power to light LED lights, (Like the harddrive activity LED light for add-in cards, that you see on the motherboard), and spin fans, but Not enough power to turn the Processor on.

Dell Support >Dimension 8400 > Service Manual

Technical Overview > System Board Components

harddrive activity light for add-in cards (SCSI LED)

The Dimension 8400 comes with an ATX style of Power Supply, that has a maximum rated Wattage of 250 Watts.
1) ALL of the LED lights combined use less than 1 Watt of power.
2) EACH fan uses 2 to 3 Watts
3) A typical Processor can use 51 to 125 Watts.

Your Power Supply just has enough power to light that LED light.
Weak voltage power rail.
Replace the Power Supply.

[ There are three power rails inside that SMPS.
Switched-Mode Power Supply.

1) The 3.3 Volt power rail
2) The 5 Volt power rail
3) The 12 Volt power rail ]

The ATX form factor for a Power Supply refers to the size, and shape of the case, for one.
Approximately 6 inches Wide, 5.5 inches Long, and 3-1/2 inches Tall.
The ATX power supply case in the Dimension 8400 however, is shorter in length.
It is 4 inches Long. (Depth)

Not an advertisement for the website, nor manufacturer.
Reference for the case size, and power cables needed,

Scroll down to see the connectors of the various power cables needed.

You may have a Power Supply with these dimensions, and needed power cables, in an unused computer.
Perhaps someone has upgraded to a better computer, and has an unused computer that you can temporarily borrow the Power Supply for a test unit.

Make sure it has at least 250 Watts (Maximum rated wattage), plus,

1) 20-pin ATX main power cable. (Or a 20 + 4-pin ATX main power cable)

[ 20 + 4-pin ATX main power cable, ]

2) 4-pin ATX +12 Volt power cable

Plus the various power cables needed for the Harddrive, optical drive/s, and computer case fan/s, if it/they do not connect to the motherboard.

Oct 21, 2010 | Dell Dimension 8400 power supply ** FREE...

1 Answer

No power on dell e520 dimension

On the 20 pin connector, short the green wire to any black wire with a paperclip. This will force the power supply to turn on manually if the motherboard is not giving the correct "ON" signal.

Feb 26, 2010 | Dell Dimension E520 PC Desktop

1 Answer

Dell Dimension 8400 power supply

It not a common problem. The problem that you are facing is is beacuse of faulty motherboard. The blinking amber is caused , becasue the motherboard is not able to distribute the power signal to the devices . You can follow the link below to trouleshoot the problem if you are comfortable in opening the computer chassis


Jan 20, 2009 | Dell Dimension 8400 power supply ** FREE...

1 Answer

Dell Dim 8400 Issues

Hi Steve,
The problem that you are facing is most likely because of bad harddrive. As you have already replaced the RAM. To confim the same , run a diagnostics on the Hardrive. You can run the same in two ways .

Check if have the utilitu partision still left on the hardrive
1. Tap on the F12 key 5 - 6 times when you see the Dell splash screen , before windows starts to load.
2. Select Hardrive diagnostics or IDE diagnostics

If the above is no there , look for the dell Rescouce cd
1. Boot the system using the dell Resource Cd.
2. Select 32 bit diagnostics from the menu
3. Run a custom test on the hdd.

If the hardrive fails , replace the same, otherwise try swaping it connector cable with the optical cable.



Oct 11, 2008 | Dell Dimension 8400 power supply ** FREE...

4 Answers

Woes with Dell

If the power light is steady amber, a device might be malfunctioning or incorrectly installed.

Disconect fan , see if it starts.

Jan 13, 2008 | Dell Dimension 8400 PC Desktop

1 Answer

Burned pins on psu

the reason for the melting could be down to one or the other, i would deffinately change the motherboard as it may be the reason for the melting and just keep an eye on the PSU

Sep 25, 2007 | Dell Dimension 8400 PC Desktop

1 Answer

Dell 8400 dead

Your gues is correct, to have had the amount of heat needed to burn the sockets there is little chance of repair. Replacement is your answer. Regards mistyman

Sep 24, 2007 | Computers & Internet

1 Answer

Dell 8400 dead

Can you tell if your hard drive is running? You can here it or feel it spinning. Are the fans running? If no, I'm 99% sure you need to replace your power supply and/or motherboard. This kind of thing usually happens after a power surge.

Sep 24, 2007 | Computers & Internet

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