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X399 taichi no power on when both CPU cables using
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boneto666 View Drop Down
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    Posted: 14 Nov 2017 at 5:11pm
Board works fine when only the main CPU input is plugged in, but does not power on if the optional CPU input is plugged in as well. 
Basically nothing happens when I press power on except for a very short mechanical noise. Then if I unplug the optional CPU input, it can power on and work again.

I have done swapping PSU and swapping cables around, so pretty sure there's something wrong with the board. 
Just wondering if you guys have any insights on this?

I used RM1000i and RM750i with 1950X for testing.
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ASRock_TSD View Drop Down
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Dear boneto666,

Greetings, this is ASRock TSD.


According to your question, we set an X399 Taichi system with RM750i power and 1950X CPU to perform the ON/OFF test in our lab.
We confirm that the system can post properly with 8-Pin CPU + optional 4-Pin CPU power occupied. 
 
Based on our test result, we provide some suggestions for verifying:
 
1. Please make sure the power connector is installed at correct orientation. 
2. Please make sure the modular power connector is connected the correct location to your PSU.
3. Please remove the VGA card and power from the system, check if the Dr.Debug code LED is running.
    If so, this indicates that the motherboard is able to boot without graphic output. Please install other VGA cards to verify.
 
If the issue still persists, please provide a picture to show the optional 4-Pin power connector for us.


Thanks!

All the best,
ASRock TSD
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datonyb View Drop Down
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you wont be the first guy to have plugged in the vga power to the mainboard

we already had one threadripper owner do this ,and that caused exactly the same issue

remember the ones for the board must say eps and not pcie
[url=https://valid.x86.fr/jpg250][/url]

3800X, powercolor reddevil vega64, gskill tridentz3866, taichix370, evga750watt gold
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Danonano View Drop Down
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Originally posted by datonyb datonyb wrote:

you wont be the first guy to have plugged in the vga power to the mainboard

we already had one threadripper owner do this ,and that caused exactly the same issue

remember the ones for the board must say eps and not pcie


^^This
For the 8 pin connection, make sure you are using the right cable.  
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parsec View Drop Down
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Originally posted by Danonano Danonano wrote:

Originally posted by datonyb datonyb wrote:

you wont be the first guy to have plugged in the vga power to the mainboard

we already had one threadripper owner do this ,and that caused exactly the same issue

remember the ones for the board must say eps and not pcie


^^This
For the 8 pin connection, make sure you are using the right cable.  


IF this is what the OP did, IMO these two different PSU cable connectors (eight pin CPU power, and eight pin GPU power) should not fit into both the CPU and GPU power inputs on a mother board and video card, respectively.

The main reason being, the +12V and ground wires on each of these cables have the polarities reversed. Or, the inputs on the mother board and video card have the +12V and ground connections on opposite sides of the connectors.

Checking the cables from a current model Seasonic modular PSU, the keying of the CPU and GPU input connectors are slightly different, but it looks like the keying allows the GPU cable to be connected to the CPU input.

It used to be worse with the keying on the PSU's cables connection end to the device, but that has been improved. This situation is one of the few remaining keying mistakes that needs to be fixed.
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Xaltar View Drop Down
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Originally posted by parsec parsec wrote:

IF this is what the OP did, IMO these two different PSU cable connectors (eight pin CPU power, and eight pin GPU power) should not fit into both the CPU and GPU power inputs on a mother board and video card, respectively.

The main reason being, the +12V and ground wires on each of these cables have the polarities reversed. Or, the inputs on the mother board and video card have the +12V and ground connections on opposite sides of the connectors.

Checking the cables from a current model Seasonic modular PSU, the keying of the CPU and GPU input connectors are slightly different, but it looks like the keying allows the GPU cable to be connected to the CPU input.

It used to be worse with the keying on the PSU's cables connection end to the device, but that has been improved. This situation is one of the few remaining keying mistakes that needs to be fixed.


I can confirm, it shouldn't fit but with a little force it does Confused 

I wish they would just unify the 2 connectors, no more confusion if they both have the same voltage and pinout....

We have seen more than a few users with issues discover this to be the issue. It's a problem because it sounds like a real newbie mistake and people often are embarrassed to admit (sometimes even check) that this could be the problem. The fact is, especially with sleeved cables, this is a very easy mistake to make, particularly when the power connectors are snug and require some force anyway.
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blindrun View Drop Down
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I am having the same issue. System was running fine. Then It stopped. Troubleshooted with another PSU. LEDs turn on, no debug lights. Click in PSU when power depressed.
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MisterJ View Drop Down
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blindrun, please open a new thread and post all your specifications as I have in my signature.  Tell us what is going on as if we have not read this thread.  Thanks and enjoy, John.
Fat1 X399 Pro Gaming, TR 1950X, RAID0 3xSamsung SSD 960 EVO, G.SKILL FlareX F4-3200C14Q-32GFX, Win 10 x64 Pro, Enermx Platimax 850, Enermx Liqtech TR4 CPU Cooler, Radeon RX580, BIOS 2.00, 2xHDDs WD
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Originally posted by Xaltar Xaltar wrote:


I can confirm, it shouldn't fit but with a little force it does Confused 

I wish they would just unify the 2 connectors, no more confusion if they both have the same voltage and pinout....




Corsair RMi & RMx use exactly the same EPS and PCIe connector layouts for the PSU end. The difference is in the peripherals' end, i.e. mobo and GPU.

To make it even worse, all wires are painted black, so one should be extra careful.
1700X ZP-B1 (stock); X370 Taichi (UEFI 3.10); 16GB F4-3200C14-8GFX XMP; 256GB 960 EVO; RX 580 NITRO+ 8GB
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Also make sure you have the 4-pin cpu power connector aligned correctly when you plugged it in......have heard of people not having it aligned correctly and the system not powering on because of this.
X399 Fat Pro Gaming bios 3.10 - TR4 1900X - 64GB G-SKILL TridentZ F4-3200C14Q-64GTZ @ 3133MHz - Vega 64 AIO with EK block - WC Custom loop - 1500W Silverstone PSU - yay
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