ASROCK Z68 Gen3 not booting and turning off-on-off

Just some thoughts. Is the board out of the case on a box? using IGPU or PCIe GPU? Try new CMOS battery, check for swollen caps, chips that may have wires shorted together or broken, burnt traces, mashed or shorted USB port and pci/e slot pins, corrosion? A bad HHD can make a system boot slow or not at all. BIOS beeps? try PS/2 keyboard/mouse. Google search for similar issue with that board?

Have you ruled out the PSU?

As PSUs get older they often degrade and rails go out of tolerance, that could cause the symptoms you described. It should be a cheap option to rule out, even a cheap PSU should be enough to get you to the post screen if the old PSU went bad.

If that checks out fine then your last option is the board or RAM.

Tried to start without RAM. System shows error 53 (which is correct) and is still running, so the power supply seems to be ok.

Ok, mainboard or RAM?

Hi there

Hope to find some help for my problem:

I've got a Z68 Gen3 Board with a Intel i7 2700K, which was running from 2012 to now without any problems.

Two days ago,windows was not longer usable, the system was extremly slow and I tried to restart. For the next 5 attempts, it turned into loading windows, but extremly slow and didnt finish it. Now, the new situation is, that its not longer possible to load BIOS or something, the system turns off after 3 seconds, then restards and so on - an endless loop. The LED-panel shows 55, which should be something like "no RAM". Switched the CPU to a i7 3770, same problem - so its not the CPU.

Maybe the power supply (Be Quiet BQT P9-650) or the board - or really the RAM? (4x4 GB) Tried to change the RAM, same problem.

Any ideas what to do?

Thanks for some help and best
Daryl