Reception lost when turning up squelch to eliminate static?

[gregvail]

I have an Icom IC-M504 VHF Radio transceiver. If I turn my squelch up to 3 (which is just barely enough to eliminate static), I can't receive any voice communications. People can hear me, but I cannot hear them. When I turn the squelch down, just slightly, I can hear communication, but I also hear the static when there is no one talking. Is this an antenna issue, a bad setting in the VHF, or just a fault in the radio?

I have a mast mounted antenna and I don't like to go up there unless I have to. I don't have a spare antenna. I tested the antenna and the coax in the following manner. With the squelch set very low, I tuned in a weather station. The weather station doesn't come in at all on my handheld VHF so I am getting some benefit from the coax and/or antenna. I removed the antenna connection from the radio and lost the signal. When I put the male portion of the coax back into the VHF, the signal came back. When I fully connected the coax to the back of the radio there is no change, neither improving nor getting worse. Seems like the signal should get better with a full connection. My question remains, is this a bad antenna or a radio issue?

Thanks for any assistance.

[gregvail]

SOLVED. Received a reply from Icom. They stated the filters on the units built before 2010 were problematic and they would repair the unit at no cost if the purchase date was within 5 years. I confirmed the issue was with the radio and not the coax/antenna by testing them with a spare radio. Don't know why I didn't think of that earlier. I guess the thousand other repairs were clouding my brain. Hopes this helps someone else with this weird issue.