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LB Maratrac A7 no power-up

Posted: Fri Jan 18, 2008 1:30 am
by 007
I just took delivery of a lowband T81 "BK" Maratrac with A7 control head. I put it on the bench, gave it power and....nothing. The head is completely dark, but the relay inside the tray is opening/closing with the switch on the bottom of the head, so I know I'm getting 13.8v to the tray. The A7 head has the optional squelch knob, and the tray has the SP01 squelch/interconnect boards to support it.

I checked the green minifuse on the logic board, and it tested okay. I almost closed it up for the night, but as I'm looking around the logic board I first notice that one chassis screw is missing (never a good sign) on the interconnect board and then my eye catches this:

Image

There is supposed to be a Cap there, but it was clipped out...the leads are soldered to the board and were snipped with a sidecutter at the ends of the Cap. Any reason why this would be done? Is this part of my power-up problem?

Re: LB Maratrac A7 no power-up

Posted: Fri Jan 18, 2008 4:40 am
by Satelite
Hello :
The large blue capacitor that is missing is a 16volt @ 1000uF
I a few of these caps.
If you need one pm me your mailing address and ill send one.
Satelite

Re: LB Maratrac A7 no power-up

Posted: Fri Jan 18, 2008 9:41 am
by Max-trac
Maratrac's don't have that cap. They have an outboard audio PA.
Did you connect both the orange and green wires to 12v too?? And check thier fuses and continuity. (I have forgotten).
Look carefully at all the pins on all the connectors to the radio and head, I have seen some bent over.
Look for burned traces on the head circuit board or for bad solder joints to the power switch there (or bad switch).