Kiwi-1: How to fix a shorted 5V input CMC (T301)
@n6gn It's also possible to pop the plastic top of the CMC with a thin flat blade screwdriver, cut the winding connections two at each end and jumper lengthwise in place of the disconnected windings.
This avoids having to heat up the pads to remove the entire CMC - a rather difficult process without the right desoldering equipment.
I needed to fix a broken Kiwi I've had sitting around here for years (customer return). Sure enough, a shorted T301 CMC.
I tried Glenn's trick and it worked great. The cover pops off easily and even snaps back on after you've jumpered the pins. Microscope photo prior to soldering left-side pins: Thanks Glenn!
Comments
@jks I really want to know how you get off the plastic top from the CMC, i have the same problem but i get the top not loose.
If you look carefully, perhaps with some magnification, you'll see there is a seam in the plastic of the part. The seam runs all the way around the part, just down slightly from the top.
Use a small sharp knife, like an X-ACTO knife, to pry the top of the part off. Just stick the knife in the seam and twist. The top should pop off. It's just held in by friction (and maybe a little bit of glue). This is why you're able to snap it back on afterwards.
You might also be able to use a small screwdriver instead of a knife.
@jks Thanks, i will try again
My Kiwi just died, there is a short circuit, the 501Y choke is getting very hot and it smells of burning. After opening you can see this:
Now the question: is it enough to pick out the burnt choke and make a bridge as in the first photo in the topic for it to work?
Yes, definitely.
Was it powering a BBG/BBB or BBAI/BBAI-64 through that connector?
BBG and I am sure that I broke it when I forgot to reduce the transmitter power and AGC at the input during the test, I only heard the grating of the distorted RF signal in the headphones. and several hundred W went through the cables, despite dozens of ferrite cores fastened wherever possible, the one lying closest to it died. I used LED legs for the bridge, everything works!
Okay, that's great to hear!