Air conditioning costs may vary depending on the damage that needs to be repaired. The cost for an AC repair in Piscataway is based on the following estimates. A compressor replacement may cost a homeowner $126 to $1,074 depending on its size and type. AC refrigerant recharge normally costs around $150 to $400. A circuit board replacement may cost between $120 and $600 and a refrigerant leak detection and repair can start from $200 up to $1600. These are just some of the repair costs. It does not include the troubleshooting service costs that normally amount between $70 to $190.