Hello all,
(I am just getting into electronics repair so excuse the noobness
)
I have an Asrock B450 Pro 4 motherboard which doesn't power on. I have access to the Broadview file.
I have checked that the PSU is working. I have the 5V standby on pin 9 and the 5V PSON# on pin 16. When I short the pin 16 and the ground I see the fan running and other voltages as well.
I have removed everything from the motherboard except the CPU fan and have only connected the 24pin power from the PSU. I have not connected the 12V power from the PSU to the CPU section.
In this condition, I see that there is ~3.3 V at the power button (PWRBTN#) and when I connect it to GND I see the potential dropping to 0 and coming back up but the motherboard stays dead - no CPU fan spinning.
I have shorted pin 16 (PSON#) and GND of the 24pin from the PSU while connected to the motherboard and I see that the motherboard powers on - CPU fan running.
CMOS battery shows +2.8 V. I have removed it and put it back after a while. Doesn't change the behavior. I don't know if my RTC crystal is working - I don't have an oscilloscope.
I have measured various other potentials. But I am flying blind here.
For example from reading stuff online I understand that the PWRBTN# signal should go to the SIO.
I can measure SIO_PSIN to be at 3.4V.
I can measure PSOUT# to be at 3.3V
I can measure SIO_RSMRST# to be at 1.8V ( I don't know if this is high or low).
As I understand, the SIO has to receive SLP_S3# and SLP_S4_S5 ( i don't know what they are) which I can measure to be zero.
Any guidance on how to go about this would be so much helpful.
Thank you all!
(I am just getting into electronics repair so excuse the noobness
) I have an Asrock B450 Pro 4 motherboard which doesn't power on. I have access to the Broadview file.
I have checked that the PSU is working. I have the 5V standby on pin 9 and the 5V PSON# on pin 16. When I short the pin 16 and the ground I see the fan running and other voltages as well.
I have removed everything from the motherboard except the CPU fan and have only connected the 24pin power from the PSU. I have not connected the 12V power from the PSU to the CPU section.
In this condition, I see that there is ~3.3 V at the power button (PWRBTN#) and when I connect it to GND I see the potential dropping to 0 and coming back up but the motherboard stays dead - no CPU fan spinning.
I have shorted pin 16 (PSON#) and GND of the 24pin from the PSU while connected to the motherboard and I see that the motherboard powers on - CPU fan running.
CMOS battery shows +2.8 V. I have removed it and put it back after a while. Doesn't change the behavior. I don't know if my RTC crystal is working - I don't have an oscilloscope.
I have measured various other potentials. But I am flying blind here.
For example from reading stuff online I understand that the PWRBTN# signal should go to the SIO.
I can measure SIO_PSIN to be at 3.4V.
I can measure PSOUT# to be at 3.3V
I can measure SIO_RSMRST# to be at 1.8V ( I don't know if this is high or low).
As I understand, the SIO has to receive SLP_S3# and SLP_S4_S5 ( i don't know what they are) which I can measure to be zero.
Any guidance on how to go about this would be so much helpful.
Thank you all!
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