First, inspect all the electrolytic (“tin-can”) capacitors for visible problems. Due either to being under-rated or a sordid tale of corporate espionage (see Wikipedia link above), the capacitors will gradually vaporize their electrolyte (and sometimes not so gradually, with a bang) until they can no longer perform their capacitorly duties, causing the monitor to go haywire. Their tops normally have a score pattern on them, but should otherwise be flat. Probable Symptoms: Monitor won’t turn on, no apparent power, black screen Blinking power LED Turns on but shuts itself off without warning* Note: This power supply board (or very similar model) appears to be used in a variety of monitors from different manufacturers. Collateral Damage With the caps replaced, it’s a good idea to check for any obvious collateral damage.
They should not bulge upward, even a little. Fault Finding By all accounts, bad capacitors are usually the underlying cause of these problems. Unscrew them and any other visible screws, then carefully pry at the seam where the two halves of the monitor “shell” come together.
There is also a surface-mount fuse on the controller board near the power entry connector. Luckily, consensus from the internet is that this filter cap on the primary side rarely fails, so unless it is showing visible signs you can probably leave it alone. Cap List Here are suitable replacement parts currently available on Digikey. Be careful when removing the old ones, as some of them are near very brittle powdered-core inductors and tacked down with some kind of glue. Upon opening the monitor, this suspicion was confirmed by several visibly bulging capacitors in the low-voltage section of the power supply. This is the one that can make your skeleton glow even if the monitor is unplugged. Visible bulging, ruptured tops or signs of leakage (e.g. brown goo around the top or seams) are sure signs they need replacing.