Hi, why not fiddle with teh pressure I think - you want it right. If youbve a procon pump like me there is a screw on the pump. clockwise for more pressure, anticlockwise for less. You need to be careful that your pressure is not low due to a loose overpressure valve or else any adjustment you make to the pump will make no difference at all. Make sure you unplyug your machine before doing anything to it.
I dont understand what your pressure problem is. can you describe it abit more? it should show mains pressure when idle (assuming your not talking about a portafilter gauge), and then go to about 9 (or 7 in your case) when pumping. Then back to mains pressure after the shot. I wouldnt think there would be any issues with a solenoid.
If you wanted to check anything, probably the first thing I would do is tighten the opv and see what that does. If your pressure geos up then you opv was too loose (a spring could have worn out a bit). If the pressure stays the same, return the opv to where it started and then you could start thinking about adjusting the pump assuming there are no other problems.
Hope that helped some!