p8h61-m lx3 wont start

[6ot4hr]

Hi, friend gave me ASUS P8H61 motherboard with i5 3470 which died after he connected shorted PSU to it.

Motherboard has 3.3V on "power button" connectors and the LED on the bottom shines, but nothing happens when I press power button... I tried to jump start PSU (green wire to the ground) and all voltage regulators on the board start up and produce voltage, even the CPU fan spins.

Board is powered by NUVOTON NCT5535D and on PIN_29 voltage drops to 0 when powerbutton is pressed, but there is no schematic online either for the board or the 5535D.

Ram is ok, but i dont have a 1155 socket motherboard to test the CPU...
Any suggestions for what i could try?

[piernov]

Re: p8h61-m lx3 wont start

Do a CMOS reset, make sure a good coin battery is in (rarely required to boot, but some motherboards need it anyway), check jumpers position.

Check RSMRST# signal.
Boardview atteched.

EDIT: correct boardview uploaded, didn't read the topic, only the message.

[6ot4hr]

Re: p8h61-m lx3 wont start

Hi, RSMRST is always present (3,3V). on the IO chip, and on the resistors near the northbridge / southbridge chip

Btw, i did some capacitors testing on the CPU itself, most of them test shorted when using diode test on multimeter, is that normal or could it be that the cpu has died?

[piernov]

Re: p8h61-m lx3 wont start

Check S_SLP_S4# and S_SLP_S3# when pressing/releasing power button.

CPU VCore line showing low resistance is perfectly normal. In resistance mode you should get between 2 and 20 ohms. If you remove the CPU, it will be in the kiloohms range.

[6ot4hr]

Re: p8h61-m lx3 wont start

Hi again, i did some testing and here are the results:


off -- on button pressed -- PSON to GND
SLP S3 3,3V -- 0V -- 0V
SLP S4 3,3V -- 3,3V -- 0V
DEEP S5 0,06V -- 0,06V -- 0,1V
RSTCON 0V -- 0V -- 3,3V
PSON 5V -- 5V -- 0V



When i pull PSON to gnd mbo starts (but no picture is shown), same as when green wire is pulled to gnd on PSU.
Any ideas ?

[piernov]

Re: p8h61-m lx3 wont start

Yeah if you force the power supply on by shorting PSON to ground, the PCH won't go by the usual power sequence and it won't work properly.

When the computer is off, SLP_S4# and SLP_S3# should be 0V. Not sure what's going on there?

SLP_S4# being present after power button is pressed is good, but SLP_S3# is missing in this case. Make sure measurements are good.

Check +1.5VDUAL at PL9. If it's missing, check P_1V5DUAL_OCSET/EN_10.