Hey guys

Bought this NS Oscar I used a while ago and it just occurred to me recently that what I've been experiencing is not normal. I've listed some observations below:

  1. After pulling a shot and taking the PF out, there's a thing layer of water at the top, sometimes it's not there, most times it is. Puck is not dry at all
  2. When I begin extraction and then stop it, the machine almost always gives a delayed backflush noise (maybe about a second before I hear it) and it's also very lackluster. When I put it through a cleaning procedure, sometimes there is only a little dribble coming out into the drip tray
  3. When I have a blind filter on, sometimes the backflushing is delayed or simply doesn't occur. In the latter case I need to actually unlock the PF slightly and then it backflushes

My gut feel is that my 3-way solenoid valve is either blocked or completely faulty. Has anyone experienced something similar and know what steps I should do to troubleshoot and fix it?

P.S. I have little to no experience opening up machines, photos or some guides I can reference would be super helpful