[sdiy] LEDs dying in LCD alphanumeric display

[Adam Inglis]

Harry you must really love that old D4!! (It's OK I understand, I used  
an SR16 for years)

On 07/11/2011, at 11:53 PM, Harry Bissell wrote:

> I had a similar failure in an Alesis D4 drum machine. The LCD was  
> backlit by 24 parallel
> connected LED chips bonded to a copper (PCB) substrate. Once one  
> chip fails, the others get
> progressively higher current and fail more rapidly.

Actually I wondered if that was the case here... it started a month  
ago at one edge, but progressed quickly over the last week.


>
> Failure to match the LEDs is a guarantee that they will burn out  
> again. The better job you do, the more
> long lasting the repair.
>
> It was a major operation but not too difficult, just fussy...


Phew! I don't mind fussy but I can't even see where to start with this  
unit! Need better glasses obviously...

cheers
Adam