Purchase breaks well within 30 days

Hi,

I purchased a $3750 dac used from a member and within a few weeks one of the two channels stopped working inexplicably.

The dac is under warranty but because the authorized repair shop recommends the entire dac board to be replaced it may take 4-6 month to get the part as the manufacturer is way behind because of covid and has limited capacity to manufacture things.  At minimum will be 3 months.

I would think
If repair estimated to be free and within 60 days or so the buyer should just be patient and not ask for refund.

But if a very lengthy repair timeline I am of the mind that a refund is appropriate but wanted input of others.

For sake of discussion lets assume seller had no idea there was problem and buyer did not contribute to problem

Thoughts?