CompactFlash, SD, MMC, USB flash storage. Anything that does not have moving parts inside.
January 18th, 2018, 4:53
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..
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January 18th, 2018, 15:23
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.
January 30th, 2018, 13:21
i have made some more misurement,
in red.
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January 30th, 2018, 18:11
Measure the voltages at coils A and B.
Measure the resistance between ground and the 1R0 coil (in the absence of power).
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- coils.jpg (167.2 KiB) Viewed 9101 times
January 30th, 2018, 19:11
in black text:
coil 1R0 to ground= 34 ohm
coil A to ground = + 1 volt
coil B to ground = + 2.8 volt
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- coils.jpg (106.5 KiB) Viewed 9096 times
January 30th, 2018, 20:48
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?
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- UART.jpg (73.24 KiB) Viewed 9079 times
January 31st, 2018, 9:16
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.
January 31st, 2018, 14:19
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.)
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