Waters 2475 flow cell

[Bigbear]

So I plugged my flow cell without thinking.
Waters just suggested I store my column in ACN, made the change to run ACN at the end of a batch.
Yesterday am I went to flush my post column pumps ( NaOH and a borate buffer) and ran the effluent through the RX coil and detector.
Now I'm attempting to back flush the cell after sonicating it for 90 min.
Waters does not offer a rebuilding service and say this part is not user serviceable. Anyone know if someone can do this?

Thanks
Bear

[Bigbear]

After back flushing while the cell was in the sonicator I was able to clear the blockage!
Guess I'll be going back to 50/50 ACN/MeOH for column storage.