Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
I'm sorry to say it, but when power variations or spikes or surges hit, if one's valued electronics are not protected with surge protectors (at very least) then the results are bad, and usually amount to breakage of the electronics.
Your board's inputs/channels/outputs (I'm not sure which, but one of those) have been blown out, most likely, I'm sorry to say.
You can try this:
First, turn Off and unplug all affected equipment, from the power at least unplug the equipment. Leave it powered Off for overnight or a few days. After that, try again. If the fault or defect persists, at that point it is certain to be permanent breakage.
Second, if broken still, decide on whether it is worth repairing to you, and seek out a repair facility. (In case it gets to this point, let me know your local zip code, so that I can recommend to you the Tascam repair centers in your region.)