Xbox one, components needed for boot sequence?

[liquidzorch]

Hello. Does anybody know the components the xbox checks during its power up sequence?

When plugging in any xbox one, normal or "s" model, the console boots for a couple seconds then enters a power standby mode. But if a component is bad, it will try again a couple times then stop, and if you try to turn it on, then it will power itself off after a couple seconds.

I know that one component it searches for during this self check it the network chip. Does anyone know what else?

I ask since I have two consoles that do not boot, have good power to cpu/gpu and try to boot 4 times then stops. In the past I have found it to be a problem with the network chip (replacing it worked) and once being the cpu needed a reball (also worked). But these two consoles have had both things done to them and I still cannot find the error.

What else should I be looking for?

I imagine ram modules, but I can´t replace them all to find out they were not the issue. (they do have 1.5v).

[stj]

Re: Xbox one, components needed for boot sequence?

multiple boot attempts on pc's often indicates a corrupt bios.
not sure if the xbox does the same.

[FiXiNGA]

Hi I have an Xbox with the same issue here.
if I press on power it beeps and No fan spin. White light come up and after 5-6 seconds the power off beep comes and it shuts down.

By observing the heat during power plugged in I can see those 4 times boot cycles as well.

is there an fix for this?

[redbaron1007]

All the xbox one needs to boot and display is the power supply and hard drive. If you don't have the HDD the system will power up normally and not display anything on the TV. Fan is good to so the system will stay on without overheating, but if the heat sink is present it shouldn't be an issue for testing. All the other modular components are only needed for updating the system software or obviously reading discs. You don't even need the power button if you know which pins to short on the header.

If you're getting the 1.5v to the ram then it probably isn't a voltage rail kicking the unit off. Have you checked all the mosfets for shorts or tried changing the on semi PMC IC near the apu mosfets? Could also be a southbridge or if it's an x/s model it could be an issue with the HDMI retimer IC.