If you have a Grainger near you, you might be able to walk in and get compatible capacitors, contactors, and control boards for your unit. If you don’t know what Grainger is, it’s an industrial supply store that carries many parts for building and construction uses.
One thing to mention about HVAC repair is to make absolutely sure you have the power off. If you’re working on the air handler, make sure both the thermostat is off and that the power to the air handler unit itself is off. To cut the power to the air handler, look for a lightswitch near the unit. If you’re working on the condenser unit outside, make sure the breaker for the condenser is off in addition to cutting power to the air handler. There will typically be a breaker box right next to the condenser unit. If you’re working on the capacitors in the condenser, take care not to short the contacts. There may be stored electricity in the capacitor which can be discharged accidentally. But other than electricity safety, it’s relatively easy to swap out the capacitors and contactor.
One other thing to mention is to take a video of the wires before you disassemble anything. Make sure you record which colored wires go where before taking things apart.
Anyone understand how he could do this? My impression is that motherboards are all or nothing–if it quits working there is no option but to replace it. So exactly how can he rewire it?
I imagine some shade-tree mechanic could essentially hot-wire the AC portion to be on full time. Bypassing all the safety switches, pressure sensors, etc., that now require a computer to do the work a simple toggle switch did 80 years ago.
Nobody with an HVAC contractor’s license would touch that. But Bubba the Yokel? Sure.
A few other cheap items that commonly cause a stoppage are the hot wire igniter, the flame sensor and the inducer fan pressure (vacuum) switch. Plus the start capacitor for the main blower. All around $20 or less.