HDD GURU FORUMS

The SSd does not show any signals (BSY DRD etc) - even not blinking for a while - nothing of nothing.

on coil 2R2 i misured 2,8 volt
on coil 1R2 0,0 volt

i suspect a spike killed the fuse diode but i am not sure which is fuse diode here..

If you are measuring +2.8V at one of the supplies, then the "fuse diode" (sic) must be OK.

If any regulator has a 0V output, then ...

1/ The regulator may be faulty.

2/ The regulator may not be turned on. Measure the voltage at its Enable pin.

3/ The regulator's output may be shorted to ground. Measure the resistance between the coil (or capacitors) and ground.

i have made some more misurement,
in red.

Measure the voltages at coils A and B.

Measure the resistance between ground and the 1R0 coil (in the absence of power).

in black text:

coil 1R0 to ground= 34 ohm
coil A to ground = + 1 volt
coil B to ground = + 2.8 volt

I don't understand why there are two 2.8V supplies, especially since there are no NANDs on the controller side of the PCB. Perhaps one is the controller's Vio supply?

Coil A (1V) would be the Vcore supply for the controller.

The load resistance of the 1R0 coil seems very low. Does the "13 1F" chip get hot?

Is there a direct connection between the 1R0 coil and any of the UART pins? I suspect that one of these pins would be a +3.3V supply (or maybe 2.8V ?). Can you tell us the voltages on the UART pins?

UART pins misures to ground to them one by one = 0,0 volts.
the 13 1F stay not hot.
the controller stay a bit hot.

What is the voltage on the Enable pin (EN)?

(Other photos of a similar PCB suggest that the "13 1F" part is equivalent to an APW8804.)