[ICOM] Re: IC-775DSP display backlight fail

[Paul Playford]

I recently went through the same thing with my DSP.  After I replaced all of 
the components on the circuit board it still drew way too much current (ran 
hot) so I wound up replacing the MAIN BOARD.  I assume the heat was caused 
by residual carbon from when the smoke escaped.

And I had problems getting that board to work.  I could not control the sub 
receiver.

There were three jumpers on the back of the old board and two of them were 
incorporated into the foil on the replacement board.  However the third 
jumper was not and that is the one that made the new board work.

de Paul, W8AEF

ZF2JL/ZF2TA  FO8DX/FO8PLA  8Q7AA  XZ0A  VU7RG




----- Original Message ----- 
From: "Martin Sole" <msole at loxinfo.co.th>
To: "ICOM Reflector" <icom at mailman.qth.net>
Sent: Thursday, September 20, 2007 12:41 AM
Subject: [-] [ICOM] IC-775DSP display backlight fail


>I have a 775DSP on the bench here with no back light. Inspection of the 
>inverter circuit showed both switching transistors had been destroyed with 
>some severe burning of the pcb. On replacement, the back light tube flashed 
>about twice and then one of the replacement transistor let out smoke.
>
> Any ideas on what is likely wrong here?
>
> Thanks.
>
> Martin, HS0ZED