control board

My American Standard Silver system was installed 2016. I lost 24 V XFMR (primary open), got a new one and heater worked. Switched to cooling from thermostat and same XFMR failed immediately. I though that maybe control board is is defected and started to change new. Existing board is 50A65-475...

I have Carrier furnace model: 58STA090---14116. It’s about 7 yrs old and never was registered, so out if warranty. I’ve been working on this for about a month. A month and a half ago my furnace went out in the middle of the night a couple different cold nights. The blower continued to work. The...