Dell XPS 8500 Won't Boot up

[mikekazik1]

My friends have a Dell XPS 8500 they bought in 2012. Last week, they rebooted the computer and it would not start up after it powered down. They said that when they tried to boot it up, the power button light comes on. It goes white for about three seconds and then turns an amber color. Normally the power button light is supposed to be white all the time. When the case was opened up during an attempted startup, the cpu fan starts up with no abnormal loudness. The power supply light shows green, and the motherboard light is also amber. Another thing to note is we hear no beeps during its attempts to boot up.

The specs of the computer are as follows:

Windows 7 64 bit
Intel Core i7 3770 3.4ghz (max 3.9ghz)
Dell 4gb DDR3 PC3-12800 non-ecc ram
460 Watt PSU
1TB HDD x2
Dell Wireless DW1703 WLAN WiFi 802.11 b/g/n
Dell Nvidia GeForce GT640 1GB

What could be wrong with it? Is the mobo dead? Or is there another issue?

 

[C12Friedman]

I would be inclined to believe the issues are related to power. Could be the motherboard's VRM is giving out, could be the PSU itself, could even be the CMOS battery is going bad. If they have access to a known working PSU, I'll suggest swapping it. While inside, they can reset the CMOS clock and look over the motherboard for any leaking or swollen capacitors. Another thing to check while in there is that all cables are firmly connected. Sometimes, reseating the ram is what is needed (I can't explain that one).
I'd start with resetting the CMOS clock and check the battery is at 3v (or replace it, they're cheap), reseating ram and inspecting motherboard capacitors
If still no joy (or obvious issue noticed), I'd try swapping the PSU for a known working one

 

[mikekazik1]

I would be inclined to believe the issues are related to power. Could be the motherboard's VRM is giving out, could be the PSU itself, could even be the CMOS battery is going bad. If they have access to a known working PSU, I'll suggest swapping it. While inside, they can reset the CMOS clock and look over the motherboard for any leaking or swollen capacitors. Another thing to check while in there is that all cables are firmly connected. Sometimes, reseating the ram is what is needed (I can't explain that one).
I'd start with resetting the CMOS clock and check the battery is at 3v (or replace it, they're cheap), reseating ram and inspecting motherboard capacitors
If still no joy (or obvious issue noticed), I'd try swapping the PSU for a known working one

I tried replacing the CMOS battery just now but that did not correct the issue. The power supply seems to boot up just fine, as it displays the green light and it seems to power everything up. My friends already reseated the ram and that did not do anything either. I inspected the capacitors and there is nothing leaking or swollen. After we replaced the CMOS battery, there are 3 beeps that play when we attempt startup. According the dell guidebook, it said 3 beeps mean either motherboard or chipset failure. Where would you go from here?

 

[C12Friedman]

I'll suggest one other thing, if the motherboard has 4 ram slots, try the ram in the other slots. Other than that trying to isolate an issue like that requires some specialized diagnostic equipment. I'm still going to focus on power here though, would it be possible to check the voltages the PSU is supplying (ie. is a multi-meter available along with someone able to use it)? I'm thinking the lessor voltages may be wonky (the 3.3v or 5v) which may cause that.

 

[mikekazik1]

I'll suggest one other thing, if the motherboard has 4 ram slots, try the ram in the other slots. Other than that trying to isolate an issue like that requires some specialized diagnostic equipment. I'm still going to focus on power here though, would it be possible to check the voltages the PSU is supplying (ie. is a multi-meter available along with someone able to use it)? I'm thinking the lessor voltages may be wonky (the 3.3v or 5v) which may cause that.

Yes, the mobo has 4 slots and we tried placing the ram in alternate slots. No luck there. How would I be able to know if the mobo VRM is going out? I never heard of that before, so I'm not sure what I would do there. What would we have to do to test the power supply? I am not familiar with using a multimeter but I might be able to do it with a cheap multimeter if there are detailed instructions on what I'm supposed to do.

 

[C12Friedman]

Testing the PSU with a multimeter is rather easy, this link should help http://pcsupport.about.com/od/toolsofthetrade/ht/power-supply-test-multimeter.htm along with this video https://www.youtube.com/watch?v=ac7YMUcMjbw
The worst kind of checking of the VRM, visual inspection is what you'll need to do, simply look for chips that are discolored or otherwise different than others. If anything is found that looks "off", post a pic of what you find - we may be able to identify the part and recommend replacement options or...

 

[mikekazik1]

Testing the PSU with a multimeter is rather easy, this link should help http://pcsupport.about.com/od/toolsofthetrade/ht/power-supply-test-multimeter.htm along with this video https://www.youtube.com/watch?v=ac7YMUcMjbw
The worst kind of checking of the VRM, visual inspection is what you'll need to do, simply look for chips that are discolored or otherwise different than others. If anything is found that looks "off", post a pic of what you find - we may be able to identify the part and recommend replacement options or...

I don't have a multimeter yet so I will start with the VRM visual inspection. Would all the stuff be on the front side of the motherboard? Or would there be anything I need to inspect on the backside of the motherboard that is not visible when you open the case? Also, how obvious or obscure would these possible defects be?

 

[C12Friedman]

Most everything will be on the front of the motherboard (at least anything repairable). I don't think that particular motherboard would have a heatsink over the VRM area but it may, if so, it would need to be removed to inspect the VRM
Sometimes the IC gets a hole melted into them, those are easy to spot (main thing to look for) other times there may be a slight discoloration and nothing more and since discoloration happens anyway, it really is a terrible method (but it's what we got). You can always post a pic if you see something that just doesn't appear "right"