WD Disk Buzzing after a PCB Swap - Any tips?

[zed]

Hi All,

I have a WD1600JB 3.5" IDE disk what came to me with a burnt motor controller chip as a result of using the wrong power supply with an external enclosure.

When i 1st got the disk, the disk would not power up - i noticed the motor controller chip was burnt out.

I found a new PCB on ebay and ordered it. I swapped the U12 chip from the faulty disk to the new PCB. When i connected the new PCB to the customers faulty drive, the disk would not spin up. It would make a beeping/buzzing sound. Similar to that musical beeping sound coming from Maxtor disks but not the same sound exacly. It was like a high pitch - buzz buzz buzz...buzz buzz buzz...

I assumed the disk had a spindle motor seizure. I opened the disk up in a clean room and examined the motor- the motor could be freely rotated without any force at all. There was also no visible sign of damage to the heads or platters.

I then ordered a 2nd PCB and the same thing happens!

The criteria i used to order a PCB was:
============================
Matching the exact full model #: e.g WD1600JB-75GVC0
Matching the PCB Board # and Revision printed on the PCB.
Matching the Motor controller chip type (Smooth 1.3)

Has anybody seen this problem before? If so - any suggestions on what to try next?

Thanks.

Attachments

Damaged PCB

[rchadwick]

Have you checked the motor with an Ohm Meter? You should get a few ohms per winding. One winding lower than the others indicates a shorted winding, and an open is self-explanatory.

[stts]

Man that is ugly. That could have burnt one of the motor windings. Then the others arnt enough to get it rotating and they will just sit there and squeel. Put a meter across the motor contacts and see how they all read.

[zed]

rchadwick, Thanks for the reply - if it is the windings - what's the solution? Platter swap into a drive with a good motor?

[BlackST]

Pm me.