[ICOM] IC-2720 Malfunction at the Junction

[Larry L. Hinton]

You may not be in as bad of shape as you thought. The six pin control cable
would plug into the center 6 pins of the mic connector due to the locking
tab. The plug will not fit into the socket any other way.

CTL       MIC
-----------8v
CTHV-------MICU/D
TDATA------EXTMIC
RDATA------PTT
GND--------MICE
MIC--------MIC
MICE-------GND
-----------MICIN

There is no power to the control head, no power on CTHV and the mic cable
cannot be plugged in for 8V. I don't see anything that could go wrong if I
am assuming correctly that the ctrl cable was plugged into the control head
properly and just plugged into the mic jack on the RF deck.

Larry
K7YBZ

>Looking at the service manual, it would appear that doing that grounded Pin
1 of the MIC jack J2001 (+8V supply) to Pin 1 of >CONTROL jack J2006 (Mic
Earth). I expect that this probably took out the 8V regulator IC2003
(TA7808F). 

>Also connected would be the 13.8V (HV) from Pin 6 of J2006
>(CTRL) and Pin 6 of J2001 (MIC) that is the Mic Hi line.