X51 R2 Won't Power Up

Question

Hello. My name is Tom and I am working on an Alienware X51 R2 for a friend.  The problem is that it will not power on.  When the power button is depressed, it powers on momentarily, spinning the CPU and power board fans, but then immediately shuts off.  I have unplugged in turn the optical drive, video card and riser, and finally the hard drive.  Even with all three of these components disconnected, it does the same thing.  The power supply is 0FWCRC 12.3 Amp unit.  The light at the end of the plug does light up.  What further steps would you recommend in troubleshooting this machine?  Is there a way to test and eliminate the power switch itself?  I see a four pin connector going to the I/O board.  I would appreciate any help you can offer.  Thanks.

Tom-G · Accepted Answer

Turns out it was motherboard.  Purchased used motherboard on eBay and swapped out processor, installed and now works OK.  One thing I noticed was the old heat sink and chip had absolutely no thermal compound on them.  Thanks for your help.

Tesla1856 · Answer

If the power connectors that hit the motherboard and drives are industry standard, you should be able to test "final" PS voltages with a $25 Digital Power-Supply Tester.

See my Alienware Desktop General TroubleShooting thread.

Tom-G · Answer

Thanks for the response.  Don't have a tester but have one on order.  Was wondering if I could just take a regular desktop power supply and plug it into the 24 pin motherboard and 4 pin motherboard connectors and see if it would turn on and stay on?  The only thing that bothers me about trying that is that the four pin connector on the power board going to the motherboard says 19V on the board,  right next to it, when a normal four pin motherboard connection is 12 v.  Perhaps the 19v on the board is referring to something else.  Can't find a manual for the MS-7796 motherboard that would help me with the voltages, but you would think they would be standard.

Tesla1856 · Answer

1. Was wondering if I could just take a regular desktop power supply and plug it into the 24 pin motherboard and 4 pin motherboard connectors and see if it would turn on and stay on?

2. The only thing that bothers me about trying that is that the four pin connector on the power board going to the motherboard says 19V on the board, right next to it, when a normal four pin motherboard connection is 12 v. Perhaps the 19v on the board is referring to something else. Can't find a manual for the MS-7796 motherboard that would help me with the voltages, but you would think they would be standard.

1. I think so since you are saying power-sockets on motherboard are standard. Also, pretty sure I saw guys connecting a standard PS to x51 on YouTube to get a NVidia-980 to run.

2. The Power-Board and AC-Adapter create a DC-DC converted (similar to a laptop). AC-Adapter outputs 19v DC. That is inputted into PowerBoard which converts to standard desktop-like MB voltages. At least, that is my understanding of it.

Locked Topics – Alienware General

X51 R2 Won't Power Up

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