[ICOM] More re: 756ProII Shutdown on Xmit

[Frank N. Haas]

First, thanks to everyone who has responded both on the list and to me 
directly concerning this peculiar trouble with the 756ProII.

Most have suggested that I look over the fuseholders. There are no external 
fuseholders or even any fuses to check on either the Icom PS-125 power 
supply or on the rig. I wasn't aware of this until I checked. There is no 
fuseholder that one can check from outside of either of these units. I must 
conclude that whatever fuses there might be are inside each device. I will 
look into this.

Some suggested checking pins and jacks. Everything appears to be in good 
order.

In my initial description of this problem I mentioned that I tried a second 
PS-125 power supply and experienced the same problem. I connected the first 
PS-125 to another 100 watt Icom rig I have here and everything works well 
so I conclude that there is nothing wrong with the power supply.

I've been looking over the schematics and reviewing the downloaded service 
manual. There appears to be a T8V (Transmit 8 volts) buss in the rig which 
is enabled when the radio goes into transmit. I suspect that this line has 
a short that is causing the PS-125 to fold back. The question is: Is it 
worth it to pursue this and possibly make more trouble or give it to the 
experts and let them do it right the first time?

This is the cost of the incredible features and capabilities we enjoy with 
these highly complex rigs.

Whether the problem is resolved by me or Icom, I'll let all of you know how 
it sorts out.

73,

Frank N. Haas KB4T
Florida