Re: Viewsonic VX2250WM - LED!

If you look at the 1st post's jpg "power supply 1", C807 is the electrolytic capacitor covered in white goop above the opto-isolator to the left of the green PWM PWB. Normal voltage across this cap's leads should be ~16V. In my photo "100-1744", I removed the coil to show C504, left of the connector. Normal resistance across the cap is ~2.5 megohms. Removing L501 helps determine whether the low resistance is upstream or downstream of the coil.

Re: Viewsonic VX2250WM - LED!

If anyone is interested, my monitor exhibited the same symptoms. No power, mo power LED ON. Clue was that the voltage across C807 was 7V. it should be 16V. Further measurements showed that the +19V rail showed 6 ohms to ground. The problem was traced to C504 ceramic capacitor (2.2uF, 50V). Removal of the offending capacitor cleared the problem. Replacement resulted in a working monitor....