FT-991 Weak HF Receive - Receiver fault

Bugger me, the dam think blew again, I was in the WPX contect with my FTdx3000 with the amp and the FT-991A was on 40m. I noticed that in IPO mode on the 991A nothing heard. Lucky I had bought 50 of those little 150 ohm surface mount resistors.

Pulled the bottom off the 991A and found R1005 just next to RL1001. The resistor had broken in two and the cct board was burnt where is sits. Its not worth trying to solder the bloody thing in there as its too small. I tacked a small piece of wire onto the relay pad where one side of the 150 ohm resistor connects and a small piece of wire onto the terminal of J1001. The ends of these two wires sat above the board a little and I soldered one side of the new 150 ohm resistor to one wire, bent the other wire over to touch the other side of the resistor and soldered it.

Looks funny but good news it works again.


Circuit: http://vk2rt.com.au/FT-991A/2017-03-23_10-51-30.jpg

Board Layout: http://vk2rt.com.au/FT-991A/2017-03-23_11-00-36.jpg

R1005 Pads: http://vk2rt.com.au/FT-991A/2017-03-25%2018.39.45.jpg

New resistor sitting on end of wires: http://vk2rt.com.au/FT-991A/2017-03-25%2019.07.03.jpg



Anyone need more help 

 Yaesu FT-991(A) Users Group (groups.io)
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1 comment:

  1. Jimmy7/20/2017

    Thanks for the post. I suppose this happens only in environments of high RF energy around the antenna connected to this rig, would you agree? If so, I suppose a normally operated rig at home may not experience this. That said, thanks for the images, I suppose one could just rig and hot glue a socket to the relay and use normal through hole resistors to replace them easily if this is a prevalent issue.

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