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XPS 420: replacing PSU... CPU heat sink removal necessary??
Hello community, trying to extend the life of my dear old XPS 420 just a little bit longer... (it'll turn 10 years old in Jan 2018!!)
It seems my PSU is done. I'm not 100% sure: the power button blinks amber light and i've done the test by jumping the black and green cables on the motherboard plug and didnt get any fan or HDD spinning.
So by way of exclusion, it looks like the 1st area to address. I can get a spare atx PSU from my office IT department (500w or above) just to test if this is the issue before I go out and buy a brand new one.
My question is this: how long does it take to perform the swap? I saw a video on youtube and the guy had to remove the heat sink for the CPU in order to get to the CPU power plug... that means removing and re-applying thermal paste which is a bit of a pain in the back.
Is it absolutely necessary to remove the CPU heat sink or is there a workaround by removing the media card reader, Xcellerator and CPU fan housing and trying to go around that way? Somebody in a forum said they did it but gave no details.
UPDATE: I did locate the 4-pin DC Power Connector to the CPU which can be accessed without removing the heatsink but the are a bunch of wires going behind the heatsink to the bottom section of the CPU (powering the HDDs) which might have problems pulling but definitely putting them back in without removing the heatsink.
Any suggestions are appreciated.
speedstep
9 Legend
9 Legend
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47K Posts
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May 10th, 2017 06:00
Lie on its side. Remove Cover. Heatsink removal is not necessary to remove the power supply.
Remove 4 screws from the back and press down the TAB to allow the power supply to slide forward.
You must Disconnect the 4 pin and 24 pin from the motherboard.
The connectors have a press tab that locks them in place.
There are data cables and wires held in a blue plastic guide attached to the power supply.
Motherboard Power connectors are 2 and the drives etc have specific connectors.
They are standard not something that requires a lot of instruction. There is a learning curve the first few times but eventually its the same for most units.
Mary G
4 Operator
4 Operator
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20.1K Posts
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May 6th, 2017 12:00
The manual has the instructions--
downloads.dell.com/.../xps-420_owner's manual_en-us.pdf
Have you ever replaced the cmos battery? I doubt that has anything to do with your power problem, but it is a cheap $2 necessary replacement for an old computer. CR2032 coin cell battery available any where hearing aid batteries are sold.
ylcorona
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May 6th, 2017 12:00
Hi Mary, thanks for your quick reply.
I've looked through the manual already but the "removing/installing Power Supply" section is a joke. It just tells you in 6 sentences how to unscrew the unit, take it out and screw a new one in... no mention of the steps to unplug and remove all power cables and then how to plug everything back in considering the issue with the heatsink i described above.
I did just replace the coin cell battery. It was worth a try since I had a spare one around but no success with that.
ylcorona
7 Posts
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May 23rd, 2017 03:00
Thanks very much Speedstep for the detailed explanation. I was able to remove the PSU without touching the CPU and heatsink. Just a few steps that were not mentioned in your post:
- the SATA/Molex plugs that connect the HDDs at the bottom of the case need to be cut off as you cant pull them out from behind the heatsink fan enclosure. In your second photo above highlighted in yellow, those are the cables that are under the balck fan enclosure. once cut you can slide the cables out
- I didnt bother fitting the new PSU cables under the heat sink. They are long enough that they go around the CPU/fan enclosure without touching any of the "hotter" components.
Thanks again for your help! with a $50 upgrade I can keep my XPS420 running for a bit longer now.