WD2500JD not spinning

I have a WD2500JD-75HBC0 drive that does not spin and is not recognized on the PC.

I noticed the smooth chip had a small burn on it, so I have replaced it but still does not spin.

I have attached a photo with voltages I have checked, can anyone give me a few pointers what else I should check.

I do work in electronics so I know how to carry out tests.

Any help would be much appreciated.


In retrospect it would have been easier for you to transfer the serial flash memory at U12 from patient to donor.

Anyway, you have verified the presence of the Vio supply (+3.3V), Vcore (+1.3V), and the negative preamp supply (-5V). Since these are controlled by the motor controller IC, then your soldering must have been successful at least in part. However, I would confirm the voltage at the output of the Vcore regulator, at the junction of the R050 resistor and the two filter capacitors, C3 and C4.

Do you see any activity (“spin buzz”) at the motor terminals during power-up?

The following URLs may help you:

Measuring VCM and Spindle Motor Current:

Tutorial - Linear and Switchmode Regulators used in HDDs:

BTW, you might like to consider joining us at The HDD Oracle. Electronics knowledge and experience is always welcome.

Thanks fzabkar, There is no activity at the motor terminals.

 I will check this out and post how I get on.

I do not see R050 resistor and the two filter capacitors, C3 and C4 although a lot of the components do not have circuit locations printed on the PCB.

Sorry, I was referring to a similar circuit. In your case there are two capacitors and a resistor to the left of L1 in your photo. These components, together with D3 and Q1, constitute a buck regulator that generates the Vcore supply for the MCU. If the MCU were shorted, for example, then the resistor may be open circuit.

The location of the burn mark on the original motor controller might shine some light on the nature of the fault. Was the mark on the motor side of the chip or on the regulator side?

I have checked the 2 capacitors and resistor in circuit, the resistor reads 0.5ohm and I assume both capacitors are in parallel, they are 78.5ohm

Attached is a photo of the burnt chip.

Sorry, the burn mark doesn’t help me. :frowning:

If you jumper the drive to Power Up In Standby (PUIS), can you then see it in BIOS, even if its model number is blank?


Is it any different if you remove the board from the drive?

I have checked this and I cannot see it in the bios even with the board removed.

Is this an eprom fault?