i would try to troubleshoot as any other laptop..NUC is closer to a laptop design than a desktop mobo. check all rails, check the system management controller (most probably that nuvoton micro) .. there must be a chip creating standby 3V3 and 5V - usually a buck controller for 3V a nd 5V rails have a LDO for the stanby voltages... e.g. RT8243 in HP laptops with 4th and 5th gen intel cpus...etc..This one is closer to a regular desktop mobo. The Nuvoton in the lower right corner isn't an EC, it's an LPC SuperI/O. I can't see the part numbers on the other ICs but nothing stands out as looking like an EC.
check the system management controller (most probably that nuvoton micro)
This one is closer to a regular desktop mobo. The Nuvoton in the lower right corner isn't an EC, it's an LPC SuperI/O. I can't see the part numbers on the other ICs but nothing stands out as looking like an EC.When the system is booted this chip can be read from i2c, but to me its reading seem fine with the system idling?
root@proxmox# sensors
nct6776-isa-0a30
Adapter: ISA adapter
Vcore: 856.00 mV (min = +0.00 V, max = +1.74 V)
in1: 904.00 mV (min = +0.00 V, max = +0.00 V) ALARM
AVCC: 3.33 V (min = +2.98 V, max = +3.63 V)
+3.3V: 3.33 V (min = +2.98 V, max = +3.63 V)
in4: 1.06 V (min = +0.00 V, max = +0.00 V) ALARM
in5: 0.00 V (min = +0.00 V, max = +0.00 V)
in6: 256.00 mV (min = +0.00 V, max = +0.00 V) ALARM
3VSB: 3.30 V (min = +2.98 V, max = +3.63 V)
Vbat: 3.23 V (min = +2.70 V, max = +3.63 Vsee a thermistor the NTC one, might be culprit?Can that be a cause why the system can only be 'warm' booted?
I can't see the part numbers on the other ICs but nothing stands out as looking like an EC.If it is of any help, I found some other pictures on the internet and also one of my own (that I forgot about)
I suspect it might be any of the 4 'large' brown capacitors
Can you point me to the missing or remnants? because If I compare the pictures in the OP (which are not my board) they look the same I think.
I also used some paper as a shield to focus the heat and it seems that the 3 transistors/diodes are at fault (see updated attachment of my last post)
you can replace the mosfet with any P-chan with with similar current rating, Rdson and gate threshold as the 2305 has.But that is kind of the problem, I have no idea what specs the 2305 part has. :-//
https://www.alldatasheet.net/view_marking.jsp?Searchword=2305 (https://www.alldatasheet.net/view_marking.jsp?Searchword=2305)None of those companies seem like something Intel would use in their mobos... and the only one I could find a picture of, has an extra dot on the mark:
Seems reasonable to me.
you can replace the mosfet with any P-chan with with similar current rating, Rdson and gate threshold as the 2305 has.But that is kind of the problem, I have no idea what specs the 2305 part has. :-//
The Si2305DS you and I linked in this thread does not have the 2305 digit code printed on the part but A5 (or A5SHB) instead.
Now, the machine reliably starts without the capacitor and I am tempted to give up like the OP did.