Today's avionics use high density connector that have fragile small pins. When installing a radio back in it's tray use the following procedure. Most avionics have a locking pawl that is accessed from the front of the radio using a 3/32 Allen key. With the radio in your hand, put the Allen key in and rotate the Allen key counter clock wise until it stops. Put the radio in the mounting tray and gentle push it home. When you feel it meet resistance, use the Allen key and start a clockwise rotation. Always be care full to gently slide the radio into the tray rocking it slightly to feel when the rear connectors engage properly.  Use pressure from your left and right thumbs on the left and right edge of the radio to help the Allen key seat the radio as you are rotating the Allen key CW. When you feel the Allen key meet resistance, stop. Just snug the Allen key tight, do not force it.

Get in the habit of performing a visual inspection of the antennas on your aircraft. Over time they will deteriorate and the performance of the system interfaced to that antenna will be compromised.

This is a picture of a VHF com antenna on the top right wing on a Cessna C-172. Notice how the bottom of the antenna has all the while anti-static paint missing. Look up the fiberglass element. Notice how most of the anti-static white pant is missing, and the fiberglass weave is visible (the brown areas).

This type of deterioration will usually cause pop-ing and snapping in the receive audio in flight. The radio may ramp test OK. The white anti-static paint that is missing is used to help bleed off static build up in flight. The corrosion at the base is an indicator that the bonding between the antenna and top skin on the aircraft is probably marginal at best.

This antenna should be replaced to restore optimal com radio performance.