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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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I have a toyotomi TAD-T40LW that will not turn on. Backstory

Customer Question

I have a toyotomi TAD-T40LW that will not turn on. Backstory - I opened it up to clean coils because it was unable to cool a small (~200 sqft) rm more than ~2-3 degrees, after reassembly it would not start at all. When I opened it back up I saw that a ribbon cable from the control panel had very unluckily gotten itself between one of the casing screws and the threaded socket - I ran the screw right through the cable piercing and breaking 1/7 wires. I spliced that connector back together and tried it, but nothing. The only fuse I can find appears to be fine. Not sure where to go from here. There's power to the outlet. I've toggled the test/reset many times. Any help would be fantastic. Thanks.
Submitted: 1 year ago.
Category: HVAC
Expert:  Gaztech replied 1 year ago.

Welcome to Just Answer, my name is ***** ***** I will do my best to help you with your issue.

If my initial response doesn’t answer your question then let me know and we can continue our conversation.

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How old is the unit?

Customer: replied 1 year ago.
It is less than 3 years old.
Expert:  Gaztech replied 1 year ago.

OK so warranty is over, putting the screw through the ribbon probably damaged the micro chip on that board, unit will be useless,

As for unit efficiency, did you find and clean dirty coils

Customer: replied 1 year ago.
they were dirty, but not that dirty - so not clear why it was performing so poorly.
Not obvious to me that cutting a connection would damage a chip, but there is no sign of power to anything anywhere when I turn it on. Found the float valve switch - does not seem to be engaged. Are there any other switches that would cut power worth checking?
Expert:  Gaztech replied 1 year ago.

You want to check the main voltage transformer.

Customer: replied 1 year ago.
How? I'm reasonably handy and can probably dig up a multimeter. How do I check if juice is getting to the transformer and/or that the transformer is putting out the proper voltage?
Expert:  Gaztech replied 1 year ago.

Did you find the wiring diagram on the unit?

Customer: replied 1 year ago.
I don't have a wiring diagram. Haven't found one yet on the net.
Expert:  Gaztech replied 1 year ago.

Probably find it in the unit itself on a sticker or something

Customer: replied 1 year ago.
Okay - yes sticker was much smaller than I expected.
Expert:  Gaztech replied 1 year ago.

Link I gave you is no good.

If you attach a clear picture of the wiring diagram I can assist you if you need it.

Will be back in 30 mins.

Customer: replied 1 year ago.
Here's the wiring diagram.
Expert:  Gaztech replied 1 year ago.

I am back, are you there?