4+4 VGA pluged into 4+4 ATX

funkydmunky

funkydmunky

2[H]4U
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Aug 28, 2008
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First time I have done this by accident. They are pin compatible (WHY?) and I didn't even realize I did it. The computer booted the same with each cable (are they the same power?)
I have this Asus Z170-e that I have been desperately trying to get it to post after I received it back from the retailer who did a bios update for it to be compatible with the Celeron 3930 I bought with it.
After pulling it in and out of the case and putting it on the work bench so many times I just automatically grabbed the first 4+4 pin and plugged it in. Did i do damage?
If not, any idea how to get this thing to post? I am getting no LED error codes.
 
What is a 4+4 VGA? The 8 pin VGA usually splits into 6+2 pin, not 4+4? Are you sure you plugged the wrong thing in?
 
Yes correct. I keep getting flubbed up with my numbers. Building two systems at once and getting nothing right. I do apologize.
I used a VGA 6+2 into my ATX 4+4. Yes dumb i know. Too many things at once.
It fit easily and had the exact same system result. Booted up, no error codes, wouldn't post though.
Board seems to run fine except the obvious.
Clear CMOS? Leave unplugged for a while? Smash it with an axe?
 
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Did the same on a server board ........F!@@#$^$%&....... If your luck power supply protection kicked in or Diodes on the motherboard protected the board...
Just plug in the correct cables and test....
 
They do not match, I've just tried to put a 6+2 pin PCIe power plug into the 8 pin power on my mobo and it doesn't fit, you could force it in but as the vga and cpu plugs are keyed differently I cannot see how you managed it.

On a side note I was rebuilding a rig recently and managed to plug the sata power cable for an optical drive into the PCIe power on the PSU, the end result - the optical drive is fried.
 
What kind of PSU was this from? Because proper 4+4 EPS plugs and 6+2 PCIE plugs are NOT compatible. They have different shaped contacts and the 6+2 plug even have a solid part between 2 of the pins to prevent this exact thing from happening!
 
Like I said your other post, you cannot plug a PCIe power cable into the motherboard's 8-pin ATX 12v connector. If you did, the power supply would either shut down immediately, or you'd see smoke coming off the motherboard (I don't think diodes would protect against reverse bias at a full 12v).

Are you're talking about a modular power supply and plugging the cable into the POWER SUPPLY'S output that's labeled "VGA/ATX"? If so, then you're likely okay if the power supply wires all the outputs the same (my seasonic does).
 
ryan_975 said:
Are you're talking about a modular power supply and plugging the cable into the POWER SUPPLY'S output that's labeled "VGA/ATX"? If so, then you're likely okay if the power supply wires all the outputs the same (my seasonic does).
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That would make some sense as he said he got it to boot - which I am assuming means he got it to power up as he says it won't post. Sounds to me more like the bios flash is corrupted or the cpu is dead
 
Nathan_P said:
That would make some sense as he said he got it to boot - which I am assuming means he got it to power up as he says it won't post. Sounds to me more like the bios flash is corrupted or the cpu is dead
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That's my thought as well. I just want to make sure I understand what he's saying he did.
 
Pandur said:
What kind of PSU was this from? Because proper 4+4 EPS plugs and 6+2 PCIE plugs are NOT compatible. They have different shaped contacts and the 6+2 plug even have a solid part between 2 of the pins to prevent this exact thing from happening!
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EVGA 750 B2. I just tried the 2pin again in the last row and it slides in easily. I examined the ends of the plugs and the board ATX12v socket for any signs of damage and there is nothing.
 
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ryan_975 said:
Like I said your other post, you cannot plug a PCIe power cable into the motherboard's 8-pin ATX 12v connector. If you did, the power supply would either shut down immediately, or you'd see smoke coming off the motherboard (I don't think diodes would protect against reverse bias at a full 12v).

Are you're talking about a modular power supply and plugging the cable into the POWER SUPPLY'S output that's labeled "VGA/ATX"? If so, then you're likely okay if the power supply wires all the outputs the same (my seasonic does).
Click to expand...
It plugged in easily. Nothing to give me any indication I had the wrong cable. PS didn't shut down and no smoke. Booted normally and no LED error codes, where as before BIOS flash I got no fan spin-up and lots of LED error codes. It is a modular PS, but I have none of them plugged in. I has two 6+2 VGA and one CPU 4+4 hard wired.
 
Upon further investigation, I notice the 2pin has a little 1mm key like extension on it, which I guess is to prevent what I did. With a magnifying glass I can see a slight bulge on that corresponding ATX pin socket. I often have boards where the plugs are quite tight, so no alarm bells at the time.
 
So I had to go try this out. A PCIe 6-pin will definitely fit into an 8-pin ATX 12v connector, with the obvious 2-pins unfilled. It'll also fit onto the older 4-pin ATX12v with 2 pins of the plug hanging over. So yeah, if you plug a 6-pin into the 12v motherboard connector, you will immediately fry your motherboard, CPU, or both.

However, an 8-pin PCIe plug will not fit into an 8-pin ATX 12v connector.


EDIT: I'm actually getting quite confused here. If it's booting normally, why does this thread exist?
 
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ryan_975 said:
So I had to go try this out. A PCIe 6-pin will definitely fit into an 8-pin ATX 12v connector, with the obvious 2-pins unfilled. It'll also fit onto the older 4-pin ATX12v with 2 pins of the plug hanging over. So yeah, if you plug a 6-pin into the 12v motherboard connector, you will immediately fry your motherboard, CPU, or both.

However, an 8-pin PCIe plug will not fit into an 8-pin ATX 12v connector.


EDIT: I'm actually getting quite confused here. If it's booting normally, why does this thread exist?
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because it's pretty weird to that to happen, it shouldn't under any circumstance occur. it have to be an issue from Mobo manufacturer or PSU manufacturer as the layout should not be the same and shouldn't fit for any reason.

The machine it's booting because some motherboards doesn't strictly need the 8pin EPS to work.. I have an X99 board that can boot without the 8pin EPS and work with no issues at stock settings, however any overclock cause issues (as expected).

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Araxie said:
because it's pretty weird to that to happen, it shouldn't under any circumstance occur. it have to be an issue from Mobo manufacturer or PSU manufacturer as the layout should not be the same and shouldn't fit for any reason.
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Do you mean the PCIe 6 pin should not fit into the 8pin EPS12v? That's what I've always thought, but after trying it and looking at the plugs side by side, it will, very easily. There's only one pin that's keyed differently, but it's an angled pin mating up to a square hole, so it doesn't block.

The 8pin PCIe won't fit into the motherboard because of a ridge between pins 7 and 8, and the 8pin EPS won't plug into a PCIe card because the keys actually block.

The 6+2pin PCIe, has the ridge on the +2 part, but it looks like it's a little easier to force in than should be (given the above post mentioning the disfigured socket).

The machine it's booting because some motherboards doesn't strictly need the 8pin EPS to work.. I have an X99 board that can boot without the 8pin EPS and work with no issues at stock settings, however any overclock cause issues (as expected).
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That wasn't what was confusing, he said at first it's not POSTing then later said it was booting. He's sort of clarified that now though.




funkydmunky said:
It boots but will not post.
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It can't boot if it's not POSTing. POST = power on self test. It's the first thing a computer does before it moves on to booting the OS. So what you're saying it's doing turning on and doing nothing else? No LED codes (they're actually not errors, they're checkpoints) means the BIOS isn't stepping through it's code. That means the CPU isn't doing anything.
 
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Mine happened because wrong modular cables on wrong power supply... Old Corsair CPU cables pins on power supply side are reversed polarity....
 
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