HP ML350 G6 System Critical Failure LED, system won’t turn on (stay on)

[PTCsupport]

yes

[PTCsupport]

In this case  HP central will perform power on and switch of task to identify the source

Observed is 

Removed Bios Battery  (bios)

server go to green without press bottom

[PTCsupport]

not my case

[ambmorais]

Just adding some info that can be useful for someone.

I have a ML350 G6 with EXACTLY the same behaviour and after nearly 2 days looking for a solution, it turned out being a slightly loose connector.

[pseud]

Like @ambmorais I'm posting to this v old thread because it seems to carry the most information on this machine and problem.  Also, checked this thread and this post on ServerFault - if anyone can track down document c03212774 linked to on the ServerFault post it might be helpful.

I've installed a graphics card which pulls 130W but with the Graphics Card Power Cable to the power supply backplane.  I believe from somewhere that the machine should provide 75W from the pcie socket and 75W from the Graphics Card Power Cable - so, should support a 130W card.  Also installed, the second SFF hard drive cage (empty of drives) and P410 controller.  There's two 750W power supplies

Here's the gorry details (lots) of what's going on:
1/ The LEDs that I read are indicative of functioning ILO2 flash on/ off (asynchronously) - they are the left most two (7 & of 8 LEDs directly to the left of the Power Supply Connectors;
2/ ILO2 works;
3/ On switching power on (the server is set to automatically power on):
a/ The power supply fans spin up;
b/ The 4 LEDs directly to the left of the System Power Connectors light in a certain order (1+3, 1+3+4, 1+2+3+4) - then go out together (about the time of the second cycle below);
c/ One of two ILO2 LEDs then goes out (the left hand one - LED 8 - about the time of the second cycle below) while the machine appears to attempt to boot 5 times before giving up - on each boot attempt:
i) Both the main board power supply failure LEDs flash together once;
ii) The fans spin up for about a second and then stop, and;
iii) The green LEDs on the back of the power supplies light with the fans;
The sequence is repeated 5 times before finally giving up;
iv) The extinguished ILO2 LED (LED comes back on and the two resume their on/ off flashing.
4/ On pressing the power button once, the machine appears to go through one of the above cycles - perhaps slightly longer;
5/ On pressing and holding the power button, the machine has a very good attempt at keeping on going (for a few extra seconds) before giving up, but then trying again a bit shorter and then a final pathetic attempt giving up fairly quickly.

If anyone out there is still poking around one of these machines and has any pointers, it'd be really appreciated.

[pseud]

After removal of the wrong graphics card power cable (P/N: 506302-001 for DL/ML370 g6 ONLY) from the power supply bakeplane, normal service has been resumed!

See my posts here:
https://community.hpe.com/t5/servers-general/ml350-g6-gpu-power-cable-part-number/m-p/7207784/highlight/true#M19526