Repair of Thunderbay 4
I've been using the Thunderbay 4's for a few years with SoftRAID and have been very happy with them. I have 2 of them set up in a RAID 1+0 so that even if 1 thunderbolt cable gets pulled by accident, or one enclosure fails the RAID continues working.
Unfortunately I wasn't expecting one of the units to fail after only 13 months (12 month warranty on the empty enclosure). I contact OWC saying that I had identified it to be the power supply that had failed. They told me they didn't sell spare parts, and they could not repair it. I asked if they could tell me where to get a replacement power supply from and they would not.
Stupidly I ended up buying a new Thunderbay 4, but rather than disposing of the old one I packed it away for spare parts.
Earlier this year I decided to get out my old Apple II's and 68K Mac's - all of which used to work fine the last time I used them, but may of them no longer work now. I found online information and learned how to repair them - mainly replacing capacitors - and now months later I have everything working. It's very satisfying - and fun to to play with those old computers.
This led me to have another look at the Thunderbay 4. Unfortunately I couldn't see a problem with any of the components on the power board - and unlike the old Apple's I assumed it was less likely to be a failed capacitor (given that they tend to fail through age I assume). However, this time I did noticed one of the components had a label on it that I must have somehow missed last time. It had a product code PPS-200-12. I googled it, and it turns out that lots of places like Mouser sell them. Whilst many places were on backorder, I even found an online shop in the UK that had one in stock.
So if anyone has an out of warranty Thunderbay 4 that the power supply fails on - the power supply board is an off-the-shelf part.
It feels like because of MacSales poor after sales support and short warranty period (a 12 month warranty isn't allowed on electronics here in the UK - as failure after only 13 months deems it as not fit for purpose) I spent around £500 on a replacement Thunderbay 4 unnecessarily.
The only consolation is that once I receive the replacement power supply I'll have a spare enclosure to be able to swap over immediately if/when either of the other 2 fail.
Thanks for sharing your tale of woe, @bilbomacuser, and I'm sorry you had to go through it. I'm equally saddened to hear that OWC couldn't/wouldn't help you on this. Hrm.