Hi all,

Seems I was a tad hasty in proclaiming my kit built and working fine.  I
had only quickly tested it by plugging it in with 40h_test running and
whacking a few buttons.  Anyway...

I have two problems, the led at 3,4 (3 across, four up with 0,0 at the
bottom left, I apologise if I have the coordinates twisted around) is
stuck on from startup.  Also, when all other leds are on in that row,
the stuck ones brightness drops to less than the rest on that row.
Turning any one of the other leds on that row off returns it to full
brightness.  The button press on the stuck on registers fine.

Secondly, 5,0 (using the same coordinate system as before) wont light at
all.

Having foolishly paid no attention in my university electronics subjects 
I am a complete novice at this.  I have however following advice in 
other posts with similar issues tested all the header joins with a 
meter, and swapped the cables about, finding no problems.

Any suggestions for where I should be looking for shoddy workmanship on 
my part?

Oh and one more thing I should probably mention, the led that wont 
light, definitely was lighting up at one point when I was testing with 
the headers held onto the keypad board by friction alone, and at the 
same time the whole row with the stuck on led wouldn't light at all.  I 
carried on assuming it was the fact I hadn't soldered the headers on 
properly yet.

trace (visually) from the broken leds all the way back to the logic 
board.

if you have a meter, check for continuity between these points.

check for continuity between the led and connections around it that it 
is *not* supposed to be connected to (like the button system).

try swapping the cables, see if the coordinates change (this would 
indicate bad cable).

reheat the solder on the bad leds (this is a good one to do.)

visually check the leds (this is hard potentially) to make sure they're 
not in backwards.

let me know if any of that helps.

Thanks for that tehn.  Reheating the solder on the one that wouldn't 
light sorted that one out, and it turned out the stuck led was in the 
wrong way around.