brother's rig won't boot

For the past week I have been trying to get his rig to boot.

His specs are:

i5 2500k (never overclocked)
Sabertooth P67
16gb G.Skill Trident Z 2666MHZ
HD 6870 1GB
XFX Pro750W PSU

What happened was he powered it on and there was nothing to the screen and yes I tried with different cords and another monitor but still nothing.

Upon opening it up I found that it was dusty as hell so I blew all the dust and turns out that his graphics card was getting no power so I tested his PSU, RAM and video card on my system with a i3 540 and a GTX 570 and they worked but my GTX 570 or my mom's HD 5450 don't work in his system and doesn't his 6870 even with 1 stick of my G.Skill RipJawsX 4GB 1866MHZ but his 6870 works in my system.

So I decided to take it all apart and reseat the cpu with and without the battery and still no power to his 6870 even with different graphics cards and RAM.

So I decided to resort to baking the motherboard and after that there was PCI-E power but the system still wouldn't get monitor power AND YES I MADE SURE EVERYTHING WAS PLUGGED RIGHT, USED DIFFERENT COMPONENTS AND A DIFFERENT MONITOR AND WIRES.

Since the motherboard now gives PCI-E power I think that it may be the processor, what do you guys think is wrong?

Is it possible that all the dust that he let excessively build up cause a static damage?

 

From your description of your troubleshooting, I can tell that you have a good idea of what you are doing.

My guess would be a fault in the motherboard, as you said baking it caused improvement in the problem. If you have a compatible motherboard available to you I suggest swapping all his parts in/on and seeing if it works then.

 

I don't have another motherboard to test with but I will do more trouble shooting.

 

try plugging the hard drive into another pc, or another hhd or whatever he has into his rig, it may be the hard drive or whatever storage he has

 

If you read the thread PROPERLY you would have know that it doesn't post it get's no bios screen and yes I have reset the bios

 

You may have dust or something that shorted the slot, or it may have blown or a trace cracked from heat, dust, a short or something internal, things happen. You CAN run a video card from any PCI-E slot provided you don't short the card's fingers (edge) on a capacitor or other near-by motherboard goodie.
Look up PCI-E risers, an x1 to x16 riser is a great way to test motherboard slots.
The slot might work but the card might not be getting the power it needs.
Consider trying the card in another slot if you have more than one PCI-E slot even if it's 2.0 x8 slot it's fine.
If you have a 4x slot you may be able to get a 4x to 16x riser and try to run the card that way. It's ghetto but it will work and really shouldn't do much to FPS, provided you can BOOT video cards from there (some boards are picky). Now what would I do with a debacle like this one?
You can find deadstock or OEM replacements for the board on many sites.

http://www.ascendtech.us/intel-lga1155-motherboard_c_mb1155.aspx

These guys sell new, used/pulls, etc. If you submit reviews you can sometimes get free warranty extension.
Just test it fully when you get it, they don't test before they ship, but they're cheap as all get-out most times.
Had really good luck with new boards, less on the 'pulls' obviously, but for 20$ a motherboard I don't care if I have to pay 5~6 bucks to ship a pair back now and then, I order a bunch, keep the ones that work, and send the dead ones back for a credit. If they work they usually stay working for a WHILE.
Bought a new 970 chipset AMD board from them in 2013 and it's still kicking just fine in the spare machine.

This H61 board here, pro version, very very well made gives you plenty of sata and slots, won't be great for much of an overclock though as the VRM's aren't heatsinked, you can glue your ones from your old board on though if you know what you're doing, just make sure they DONT FALL OFF onto the video card.
http://www.ascendtech.us/asus-cm6630-90pa0440-m0xbn0-motherboard_i_mb90pa0440m0xbn.aspx
It's 100$ but it'll fix your computer, and it's WORTH FIXING!

Here's a 65$ DELL motherboard, P67 like the one you're replacing!
http://www.ascendtech.us/dell-aurora-r3-system-motherboard-46mhw_i_mbdell387y6r3al.aspx
Featuring ALL SOLID CAPS and HEATSINKS on the VRM.
Make sure you can remove this from it's metal plate to use it in your PC (call AscendTech).

*now if you'll follow me down here into the Bargain Basement*
Rubbish 32$ who-cares as-long-as-it-works OEM board:
http://www.ascendtech.us/hp-compaq-656941-001-desktop-motherboard_i_mbdshp656941001.aspx

Vicious Minimus model don't even know if it fits/mounts in a regular PC case but WHO cares? 32$ model...
http://www.ascendtech.us/dell-wvtjn-optiplex-990-q67-motherboard_i_mbdelwvtjnot990.aspx

CHEEP CHEEP CHEEP Bird says YES YOU CAN! At 35.99$ this one even looks like it has m-ATX mounts:
http://www.ascendtech.us/dell-vnp2h-optiplex-990-dt-motherboard_i_mbdelvnp2hop990.aspx

Keep in mind many of the major-brand OEM boards don't come with IO plates for the rear-ports, but that's OK it's not needed to work. It is the repair man's / purchaser's responsibility to MAKE SURE IT WORKS!
The more you spend the more likely you are to get a NEW board. Not all boards are priced to accurately reflect the quality or class of the board, some stuff they're clearing out old stock, some stuff is more rare, etc.
Get what will work with your PC. Chances are the ASUS board is the best bet, White-box OEM with 6~12 month warranty or something along those lines. Get a board, test all the ports & devices on it, if it works, profit!

Yes, it's worth it to fix any i5/i7 2xxx and above PC if it alls it needs is a motherboard.

Amazon and newegg might also be of help but I stopped using the egg when they got too big for their britches many moons ago (7 years?). Amazon has a really top-notch return policy and were extremely fast to credit me whereas newegg drug it's bottom end and waited almost 2 weeks for a credit after getting it 3 days later.
--- Post updated ---
Intel p67 motherboard, new, 83$ on amazon
https://www.amazon.com/Intel-Desktop-Board-DP67DE-BLKDP67DEB3/dp/B004RP6YKO
--- Post updated ---
1 used p67 asus motherboard, 100$, USED, make sure seller garuntees it's working/small warranty
https://www.amazon.com/P8H67-M-REV-3-0-Supported-Motherboard/dp/B004QF0VFO
Would go with Ascendtech's Asus m-ATX board over this one anyday but it's here!

PCI-E riser (can be useful!)
https://www.amazon.com/USB3-0-Express-Riser-Adapter-Connector/dp/B072MZ71MY

Try in bios if you can get it booted on your old board on integrated graphics to set slots for x8/x8 configuration, it will work if it's the latter part of the x16 slot that's bad as it shuts those traces and sends them to the other slot.
Yes you can put the video card in any slot if you have 'open-ended' slots, if not have those, get that riser, if you have room to mount video board, you can test it (and future boards), or possibly rig it to work.
You can also boot to the secondary PCI-E x16 slot, if your other one does not work, to no ill effect.

Processors don't usually die unless you over-volt the stuffings out of them, at that point, you'd usually see socket or processor pin-landing damage (darkened pins).
Unless he was massively overclocked, I doubt it died. Source a used base-model pentium or celeron for that socket to test if needed. surely you can snag a cheap on for like 20$ somewhere online.
I would seriously consider changing the motherboard as since you said messing with it, changed the symptoms slightly. There's lots more to go wrong on a motherboard than with most other things in the computer sans maybe the PSU or GPU.