a unwise teardown

A (un)WISE teardown

My WISE chucked up a #3 error code the other day, so I contacted Robin at WD to arrange a fix… and then the devil on my shoulder suggested I have a go myself:D. I’ve never seen a WISE ripped apart to this degree, so I thought I’d share it in the hopes of demystifying our little magic boxes.

(Machine is an ex-demo whose warranty died with the last stegosaurus, so there’s absolutely no danger; if yours is still in warranty do not open it!)

Error 3 has to do with the self-test not completing, apparently, and one of two things could be happening:

a) the limiter magnets aren’t catching the end(s) of the cycle, and/or
b) the self-test is timing out because the motor is too slow.

Here are the magnets in question – they connect to the “push” and “pull” terminals on the mainboard:


They’re working properly. That leaves b): motor too slow. To be honest, it has been slowing down for months, and it may have dipped just below the self-test timeout threshold.

First and easiest test is for the power brick. Should be chucking out 15V DC, and my multimeter read 15.19 V. Power supply is fine, so the motor is seeing the required voltage (12V, oddly – why a 15 V supply? Maybe the motor is being overclocked). Next step is to lubricate all the moving parts in case the motor is being slowed down by friction. This is where it gets gory;).

Subframe and connections removed, then the end-cap from the non-motor end, and the worm drive and puller head comes out:


There was quite a bit of crud in the grooves of the worm drive, so I took the puller off and blasted it with some acetone, along with the inside of the puller. Quick dusting of WD40 to both, and now the worm gear literally falls through the puller under gravity with almost no resistance. That leaves the motor and gearbox… sigh:


This is what it looked like after cleaning; the gears were all caked in old grease and the casing had plenty of metal swarf in it. Took all the gears off their pegs and cleaned everything, followed by some black PTFE dry lube. Bit of WD40 inside the motor, too.

(In case, like me, you’re tempted to change the motor for a faster one, here are the details:

DSC03871.JPG DSC03872.JPG

It’s 77 mm long, 37 mm in diameter and the locating hole pitch is one inch. It’s 4500 rpm before gearing, so a 5000 rpm motor – if you can find one with that worm spline – will give a 10% speed increase.)

Right – everything that can be cleaned and lubed has been cleaned and lubed, so let’s put the sucker back together and pray… plug in, switch on… and the puller flies backward faster than it did when I got it. Problem must have been the clogged-up gearbox.

This fix cost me zero pounds and maybe an hour’s time; I have absolutely no idea if the WISE can be fixed by any vendor over here, but I bet the fee is extortionate even if they could. (And if they can’t, it goes back to the US – more time and more money.)