Sorry to hear that; similar story here:
Short version: Mine gave up too after several days of happy post-surgery performance, after having replaced everything upgradeable.
Long version: Four plus days of burn in, then burn out. Found it shut off and the chip looked ok, but smelled bad; the fuse on the regulated 13,8v psu was burnt too. After replacing the fuse, the psu was no longer regulated at 13,8 but at 2x (!) that voltage! I found out the hard way, when, after changing fuse, the lepai wouldn't start at all (no led, no nothing). So, I plugged it on an audiophonics 2020 board and its chip literally blew up with a spark and had a silicon piece burst out leaving a crater on it... Add another amp and a psu destroyed during lepai-troubleshooting. Then took the lepai to a Kingrex psu, causing it to have its fuse blown, indicating that something is terribly wrong in there. Verdict: Three healthy devices and the lepai itself (with man-hours of modding on it) gone in one evening. Frustration...
The only way to start it up now is with a non-regulated fuse-less wall wart. When this happens the relays never click, whereas the chip & heatsink go very hot very quickly - didn't leave it on for more than seconds. Please note that right after all modifications the thing was running much cooler than before, cold to the touch on the outer casing that is. Oh, and the sound!!!
Question (not that I'm not going to try it anyway and post back, with pics should it resurrect) would be whether this lepai -and maybe most failing ones- might work again if the chip is replaced. Maybe 13,8v constant is too much? What do you think?