I've got a spectrum SB multi-temp SR2. Zone 1 is not cooling and I have almost no temp differential when zone 2 is on and in high speed cool when zone 2 goes into null zone 1 starts to cool good with a temp differential of about 4 degrees but as soon as zone 2 kicks back in my temp differential goes away and zone one starts to warm up. I have changed the hot gas solenoid in zone 1 already and this did nothing. with unit running in high speed cool in both zones suction pressure is high at about 75 psi and discharge is a little low at 200 to 220 psi. the unit passes a full pretrip and a unit running pretrip. any help would be greatly appreciated