Data recovery and disk repair questions and discussions related to old-fashioned SATA, SAS, SCSI, IDE, MFM hard drives - any type of storage device that has moving parts
September 18th, 2018, 6:23
Hello,
i have here a WD20EFRX - NO FUNCTION
I remove bad diodes D4 and D2 + R43 (now bridged).
PCB is only bsy. -> No spinn.
I can see near L6 D7 a chip with letters ASPAD the case has a little hole
(or may be a simple surface damaged) !?
What is the function of the chip ? (Power reg. ?)
what can I test next?
Thanks for any help (and have no donor pcb here).
September 18th, 2018, 15:25
DIAGS4711 wrote:I remove bad diodes D4 and D2 + R43 (now bridged).
R43 is in series with D3 and D1, not D4 and D2. :?
DIAGS4711 wrote:I can see near L6 D7 a chip with letters ASPAD the case has a little hole
(or may be a simple surface damaged) !?
What is the function of the chip ? (Power reg. ?)
A photo of the area would help a lot, but if you are referring to Q1, then that's a MOSFET. Q1, together with L6 and D7, constitutes a switchmode regulator with PWM control provided by the motor controller.
September 21st, 2018, 10:41
Hello fzabkar,
fact is D2 and D4 is damaged.
I get now a new pcb and all works.
Thanks
September 21st, 2018, 15:22
DIAGS4711 wrote:fact is D2 and D4 is damaged.
Then I would have expected R60 to be open circuit, not R43.
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