WD5000BPKT-75PK4T0 can manually spin but is stiff

[gledenbach]

Hi, I have an WD5000BPKT-75PK4T0 that will not spin up. The board looks fine, I can manually spin the motor but it is stiff. Anybody have a solution for this?
Thanks,
Greg Ledenbach

[jerovsek]

Hello,

did you open drive?
Post PCB Picture(site with parts)

[gledenbach]

Hello Jerovsek,
I connected it to a DeepSpar before opening it and it would not get past busy. I did open the drive and looked at the heads and platters. There does not appear to be any damage. The head can be moved, and the platters can be turned using a torx screwdriver. However the platters have a lot of resistance when trying to spin them. If I turn on the power and spin the platters it kind of looks like the motor is trying, but can't spin them. I have attached board pictures.

Thank you,

Greg Ledenbach

Attachments

[fzabkar]

When you say that "the head can be moved", does this mean that the heads are parked on the ramp? Sorry if this is an obvious question.

If the spindle bearing is tight, then perhaps increasing the drive to the motor might be sufficient to spin it. One way to do this would be to locate the current sense resistors and add an additional resistance in parallel with them. This would increase the current limit.

I can't tell which resistors sense the spindle current and which sense the VCM current, but I believe the attachment identifies the possible candidates. The VCM resistors would be floating and would connect to J1. The spindle resistors should connect to ground.

Attachments

VCM.jpg (62.54 KiB) Viewed 5528 times

sense_resistors.jpg (167.36 KiB) Viewed 5528 times

[gledenbach]

Thank you for your reply Fzabkar,

Yes the heads are parked. I gently moved the heads slightly, not over the disks, to be sure they were not frozen. Thanks for the advice. I will try and figure out which resistor is the correct one, and what the value is.

Thanks again,

Greg

[Doomer]

It's very unusual for 2.5" drives to have a motor seizure, although it is still possible. Other possibilities:
- The platters spin fine and you just overreacting over it. And the drive wouldn't spin because of dead PCB. Can be ruled out if compared with a good drive.
- There is something between HDA and platters or between the ramp and platters, a slider, for example. And that preventing platters from normal spinning. Check that all sliders are intact.
- HDA is bent and touching bottom platter, preventing it from spinning. Check HDA geometry.