"Meat Plow" wrote in message
news
On Tue, 22 Jun 2010 13:47:00 +0100, Arfa Daily ǝʇoɹʍ:

Anyone know if this pro DJ unit has a mode whereby the button
function-sensitive backlighting can be turned off ? I've not seen a Mk3
before, and don't have the manual for it. The one that I've just fixed
was in for a mechanical problem on the deck, which was straightforward
enough. All of the buttons work and do as they should, but none light up
when pressed. The "Vinyl - CDJ" indicators don't light either, although
the central jog display correctly shows "Vinyl" or nothing, when the
button is operated. There's so many different LEDs involved here, that
it seems unlikely that there is any 'fault' as such, and the job ticket
doesn't mention any such problem, so I'm wondering if a soft switch-off
function has been put in, to stop the console looking too 'busy' in the
dark, if some DJs prefer it that way. Or possibly I suppose, if all the
LEDs are taken up to some common supply rail that's just for them, there
might be some little wire ended or sm fuse, as Pioneer are so fond of
using in '1000s ?? Anyone know ?

With all the lights and commotion in a club where you would find pro dj
equip I would think that some console lights would hardly be a
distraction warranting dimming.

Yep - quite right. It was in fact a genuine fault. There are many picofuses
on the MJCB board, and one of these feeds 12v out on a rail called "VLED".
Bit of a giveaway, really ...

For future reference for anyone who might be interested, it is IC1513, and
is rated at T315mA. Replacing it restored all the LEDs to normal operation.

My thanks, as ever, to Mark Z, who managed to find a copy of the schematics
for me. Cheers Mark - it was a big help :-)

Arfa