linked capacity plus

I'm currently pulling my hair out dealing with my Linked Capacity Plus master repeater (SLR5700) which is constantly generating "Excessive Number of Collided Packet" alarms. I am noticing that this repeater seems to be pulled out of the trunking pool when this occurs. Out of all of my repeaters...

I know it's sometimes hard to answer questions without a lot of detail but I'm hoping I won't have to give up too much for question. We have about 15 sites in a 20 mile radius. We wanted each site to have their own repeater with one channel, maybe a couple more, to be able to communicate...