Would you mind telling us which CPU you have in mind?
Or are we going to play a nice game of "let's hope this mobo's compatible"?

#2008
ETA for Kaby Lake is 11.01.2017 in most shops. Soon enough?

#2011
Please get a PSU that can at least manage 80+ Bronze.

The 120$ for Microsoft Office hurt a lot. Is that really necessary?

#2014
Talked to him and he's got a noctua cooler which means he can get a new mounting kit for free.
Yes, minfactory ships to Finland for 20€.
Which ASUS cashback?

#2015
I hope you bought 4x16GB.
Another B85M Pro4? If it worked before, apart from you getting a used/slightly broken one with only 2 working RAM slots in exchange for the DOA one, then why change anything? A new one should work properly.

You have no idea what I've seen already. Humour is the only escape because some days you actually meet someone who is that stupid. I'm glad you're not.

System connectors shouldn't kill it, they'd just prevent form turning on.

It actually worked before, which is new information, I wish you would've told me sooner.
Let's rule out connections for now, since you got those right before or it never would have worked.

That leaves us with
a) that mobo died too or
b) something else died and the mobo doesn't want to turn on.

Let's hope it's not the CPU, because that's a pain in the ass to test.
Remove the GPU, HDD/SSD, everything not necessary to boot and all but one RAM stick. Try again. If it doesn't work try a different RAM slot, if it still doesn't work try a different RAM stick.

Ideally, if you can, get the CPU tested in a different mobo.

The only 400W EVGA PSU that I know of is the EVGA 400W and it's not good.
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story6&reid=436
I mean I still wouldn't recommend the 430W and so on, just because it's horribly outdated tech, but the 400W is genuinely "barely spec"-levels of "not good". It's technically all still ok and legal, but way too close for comfort.
Unless you have been very unlucky and got 2 bad mobos in a row (unless it's the CPU that died of course) there must be some reason. The irony is that more expensive mobos can actually tolerate worse PSUs, not the other way around.

This is still just a guess, but either you are awfully unlocky or it's probably that.

So you didn't connect the power button and it won't turn on? Geez, I wonder why.

If only there was a booklet sort of thing with instructions, maybe with a helpful picture to tell you which pin is which if you can't tell by the, admittetly a bit confusing to the novice, labeling on the mobo itself, you know, to help you manually install these things. One could call it an instruction manual. Oh wait. THERE IS ONE!

http://i.imgur.com/kz5uyoT.png

WHAT A TWIST! WHAT AN UNEXPECTED TURN OF EVENTS! READING THE MANUAL WAS THE KEY ALL ALONG!

So much for that.

It's not your PSU.
If there wasn't enough power to even boot it would have never worked in the first place.
The fans spinning at half speed mean that fan control is working. If 1W for a fan is too much for your PSU then that pc would have never booted. Also for fans to run at half speed without fan control doing it on purpose the voltage would have to be half of what it should be. In that case not even the LEDs on your mobo would turn on. The PSU would also either shut itself off or catch fire/explode because something would have to be seriously wrong.

"FF" doesn't mean "Fault Found". The codes are simply hexadecimal numbers ranging from 00 (=0) to FF (=255). FB-FF are not even defined and carry no explicit meaning. FF however implies that even the part responsible for figuring out what's wrong got no idea whatsoever so it just throws out the highest number it can, indicating that on a scale for "how bad is it" from 0 to 251 your problem is a 255, literally FUBAR.

Say goodbye to your motherboard because it's dead, Jim.

#2008
I'll post again once Kaby Lake is in stock in a few shops.

#2009
Yes.

However since Kaby Lake is identical to Skylake except for the iGPU I'll take any bet that some people who don't need the iGPU will run it with Skylake drivers.

#2005
40% overclocked, 60% on stock clocks is an absolutely reasonable performance increase for an upgrade.
Oh wait it's been 6 years and it's the same fucking price.

Meanwhile GPU performance for 300$ tripled in that timeframe.

#2006
Should be doable then I guess.
When do you want to build? Kaby Lake has been launched isn't quite available yet and neither are the new mobos.

Well we've got 2/3.

The GPU doesn't need any extra power, the mobo appears to have power, so you connected at least one out of 2 connectors the mobo needs, but what about the other one and the power button?

See #1997

The 5820K (Haswell-E) is the predecessor of the 6800K (Broadwell-E).

Nope, Xeons are exactly the same except more expensive.
Also since Skylake you need a different mobo chipset for them because some Xeons without iGPU were cheaper than i7s with iGPU at the same speed. And people had the audacity to buy those instead of i7s for 100$ more. Can't have that.
So as an alternative to the 4790K the E3-1230v3, 1231, 1240 or 1241 would work, but at 3.7-3.9 GHz they are simply slower than a 4790K and single threaded not much faster than the 4570 you already got.
Except for some features they are literally identical. I mean literally. The difference between selling the same chip as an i7-4771 or as a Xeon E3-1241v3 is which features are disabled.

The main difference is ECC support. If you don't know what it is you don't need it.

They are meant for servers and the profit margins are insane. So unless you're trying to build a server don't bother.

EDIT:
Moist he wants better performance than the i5-4570 he got. For rendering. Get the fuck out of here with your Pentium downgrade. It doesn't matter how cheap it is to downgrade, it's still a downgrade.

And a single Xeon E5-2679v4 is not an extreme example.
You need 8 Xeon E7-8890v4. 192 cores, 384 threads, 60k$ just for the CPUs that's when you're living the high life.

4790K -> fine
6700K -> need a new mobo, new RAM and a new cooler (doesn't come with one)
There is the 6700, which does come with a cooler and it's 40$ cheaper, not being overclockable isn't a downside in your case, but it's also a bit slower. Slower than the 4790K, need a new mobo and new RAM -> not worth it imho.

1080 is about 20% faster than a 1070. On a price to performance basis it's obviously not worth it, but if you want/"need" the extra performance you don't really have a choice. It's not within budget if you want a 6700K though.
Might want to wait and see if nVidia announces the 1080 Ti at CES in a few days. The 1080 Ti will definitely not be within budget, but the usual price drops might occur.

Which 1070 depends on the price bracket.
Ignoring the "as cheap as possible" category, since it's pointless for a 400$ GPU there's 2 categories, with minor performance/temperature/noise differences, but a 20-30$ price difference.
In alphabetical order the Gigabyte G1 Gaming, MSI Gaming X, PNY XLR8 , Zotac AMP! Edition are in the first and the
Asus ROG Strix OC (ignore the non OC version), Gigabyte Xtreme Gaming, MSI Gaming Z, Zotac AMP! Extreme are in the second, more expensive category.
Prices can vary based on stock situation, so a GPU from the first category being 30$ more expensive than one from the second doesn't make it any better. It just means the shops are running low on stock. Same within a category, the most expensive isn't necessarily the best.

Not recommendation for EVGA this time, their 1070/1080 have a nasty habit of exploding. Sure, the later versions should already have the fix applied, sure, you can prevent it by applying the thermal pads yourself, sure EVGA will replace the broken GPU no questions asked (although maybe not a burned mobo), but why deal with all that? Good customer service is not a reason to reward mediocrity.

Well there's the usual performance gain from Hypethreading, but yeah, there's no Skylake CPU available that'd be faster than a 4790K. Skylake with 6-10 cores won't happen until Q3.
Don't get me wrong, the 6500 or 6600 would still be an upgrade compared to the 4570, it just doesn't seem worth it for 10% or 20%. I mean if it feels sluggish right now 10% probably won't be enough.

Almost the same for Kaby Lake, sure 4.5 GHz are nice, but we're talking ~10% faster than a 4790K which is fairly laughable compared to the >20% single threaded and >50% multithreaded that you'd get going from the 4570 to the 4790K. Sure, another 10% on top of that are nice, but is it worth 2 to 3 times the cost?

Then there's Broadwell-E for 400 or 600$ (6 cores, can't afford more), but the mobos for that are never less than 150$ and you need DDR4. Single threaded it wouldn't even be a noticeable upgrade and definitely inferior to a 4790(K)/6700(K)/7700(K) so it's only an option for programs that scale well with more threads.

Other than that Zen, but prices are still a wildcard so that might not work either.

Zen might also be an alternative. Depends on prices, actual launch date and depending on how much you'd benefit just from more cores also on the final clockrates.

Skylake, Kaby Lake, Zen all use DDR4 so it wouldn't be an upgrade, rather a replacement. New mobo and RAM obviously will reduce the available budget for GPU and CPU.

The other option, especially if more cores don't help much would be to look for a used 4790K. You should be able to find a dud that didn't overclock well, which doesn't really matter since you can't on that mobo anyway, and get performance comparable to the 6700K thanks to the 4.4 GHz stock clock for a fraction of the cost. No new mobo needed.

If you were to get a new CPU + mobo + RAM would you want to overclock?

#1991
Raidmax PSUs are famous for things PSUs shouldn't be famous for, e.g. spontaneous combustion.

It's most likely a case of the PSU being sold as a 500W PSU, but not actually being rated for 500W. Probably the usual "take a 300W PSU, put a 500W sticker on it" strategy to cost reduction.

Any actual 400W PSU would be sufficient.

There are no good deals atm though, here's 2 options, depending on how much you're willing to spend.
http://pcpartpicker.com/product/zNK7YJ/evga-power-supply-100b10500kr
http://pcpartpicker.com/product/DPCwrH/seasonic-power-supply-ssr550rm

#1992
Kaby Lake will be announced in a few days.

Neither Skylake nor Kaby Lake will physically fit that mobo.

Budget?

Are you hitting the CPU limit or GPU limit or are you close to both? No point in upgrading the GPU if it won't do anything.