no go on tc5r sometimes

[moggy12]

hi to all i have a tc5r just joined stafford rc club few weeks back really love it but on a few heats car didnt have any power i run lipo with deans connectors if i mess with wires from battery and esc comes back alive so i'm wondering if the deans connectors are worn out or bad soldering they have shrink wrap round where the soldering should be but as i'm new to rc do'nt want to take shrink wrap of as woulndt have a clue how to put back on is there anywhere i can take my tc5r to have new deans connectors soldered on ? i live near stafford so if anyone could help me would gladly be appreciated thanks