Makita SDS HR240 fault - any ideas?

[flintandsteel]

Not exactly a woodworking tool itself but used on site occasionally.
Plugged it in, pulled the trigger and it ran 2 seconds and now totally dead.
Not the fuse.
Was working just fine a couple of weeks back.
Is this a known fault and rectifiable without huge expense?
I 'm thinking there's a small on board component just popped.
The lead is in good order but not checked internal connections yet just in case it's a cable break.

 

[Racers]

Cable break is the norm on corded tools.

Pete

 

[flintandsteel]

I tried the old waggling it about trick which often reveals a break to no effect. Now to get serious.
Easy to strip the cover off.
Tested the cable and it's fine as in it lights up a bulb.
On cable entry to the trigger there's a big square ceramic cap across the terminals but as far as I know that just supresses interference and won't effect the running.
I'm wondering if brick dust might be stopping the trigger working properly or have lifted or jammed a brush off the spindle?
WD 40 maybe?

 

[Racers]

WD40 is flammable so near sparky brushes isn't a good idea.
Are the brushes o/k?

Pete

 

[flintandsteel]

Brushes are fine, not much ware as it only get occasional use these days. Checked the brush springs, all good. Checked the armature (is it?) it rotates fine.
I'm thinking it must be the trigger failed. While it ran briefly I'm not sure it even reached full pull.
Is bypassing the trigger for a brief test a good idea?

 

[Racers]

Yep, if done safely.

Pete

 

[flintandsteel]

Thanks Pete
It will at least let me narrow down the search or locate the problem.
I think my local Makita repair shop charges £35 just to look at it then time with a base of 1 hour for the repair plus the parts.