Asus Maximus VI hero wont turn on (no fan, only lights)

NoobyNoobyDo

Commendable
Aug 11, 2016
13
0
1,510
This morning i tried to turn on my pc and it didnt...

I checked everything, it came to the point where i just took out the MB and tried to make it work with only the CPU. No result, only power and reset button lights work.

I tought that it was the psu, but the unit turns on and with direct measurement it has minimal fluctuations (+- 0.02/05v) an the 14th pin only gives -11.4v . I tried with another psu, it didnt worked eighter.

When I was putting back the 24 pin connector there was some crack an a little smoke from the are of the conector, but aftee inspection there wasnt any sign of burns (seems like a small short in the connector itself when i was conencting it). The fan turned on for a.second there.

I checked the condensators, no signs of leaks or damage, when checking the transistors found one defective (2 readings) and one reversed(reading in the right pin, nothing in the left one o_O)

any idea how can i proceed from here?

My rig:

ASUS maximus VI hero
Intel i7 4770 3.4ghz
Corsair vengance 8gb
Kingston furyx 8gb
Msi gtx980ti lightning
ssd corsair
Hdd western digitak
CoolerMaster gx650 bronze+


p.d. I installed the gpu and the psu like a month and a half ago. The pc has like 4 years
 
Most likely motherboard failure, after putting back the 24Pin cable with the wall plug still connected?

Have a look at the back of the board. On which surface did you test the motherboard? Foil or other packaging is not suitable and will most likely lead to a short on the back.

reset BIOS /clrCMOS by jumper
Try using one RAM (switch RAM Slots if not working), CPU with cooler, PSU: ATX12V 8Pin plugged in as well as the 24Pin main plug, HDMI to motherboard.
Power on
 

NoobyNoobyDo

Commendable
Aug 11, 2016
13
0
1,510


Yup tried everything. I put the mb on top of the plastic that came with it on my table.

The popping stuff happened well into the process of trying to figure out the problem: i checked the psu pins then put it back, turned on and it didnt even light the buttons, i checked and one side of the 24pin conmector wasnt tight so i just pushed it a little and the popping/little smoke happened (the cpu fan started for a sec that moment), the motherboard was inside the case at that time.

I visually checked it and there were no visible signs on the back nor front (all caps seem fine, there was a ver little quantity of something like green dust near the connector (im not sure if thats just common dust tho).

Touched the circuits and nothing is hot (tought about a failure of the integrated lan).

The only thing i managed to find on the MB was that transistor/MOSFET (the one thats closer to the 24pin connector and tje dust i wrote above) with double and inverted readings via DMM.

Forgot to mention that apart from the MB buttons lights theres no signs of life (no cpu fan at all, no error display or sound, no ethernet light).

Tried to turn on the mb without the 8pin line, but nothing changed.

So i dont know if that transistor killed the mb and i should try to replace it, or the VRM died from some power issue when i was sleeping (the pc was off but when i woke up my dsl modem was off and i had tp reconnect it to be able to turn it on again, maybe some electric discharge through the network cable), or the cpu died (shouldt the psu at least try to work in this situation?)
 

NoobyNoobyDo

Commendable
Aug 11, 2016
13
0
1,510
The plastic is the thick one. Doubt it will be conductive, and the board vas dead before i even put it on it.

Update: i changed the dead mosfet and now i found out that the MB boots when I disconnect the CPU. I was afraid that the cpu died but tested it on another MB(asrock h81) and it was working.

So the problem lies in some circuit that controls the cpu or theres something wrong with the bios.

Any ideas? Vrm?