I checked the LED strings by using a 36V supply through a 1K resistor to power each string separately, and measuring the voltage drop across the string. Inverter components checked out: diode, inductor mosfet. Inside the case, voltages were good: input 19V, 5V and 3.3V on the signal board, 19V on the LED driver board, and when the LEDs were working, 39V going to the LED common. Turning off and on would sometimes get the lights for a minute or so more, though they lasted less time and sometimes it just blinked on for a moment. Flashlight showed image, so it was just the backlight failing. Eventually or immediately the last light would go dark. The symptoms: turned on fine, but after a few minutes or less one or more backlight segments would go dark, leaving the monitor with only part of the bottom edge illuminated, as if with spotlights on a wall at night. The datasheet for the MP3394 LED controller was of great help in understanding operation. First I found that there's very little information about problems, repair, or available parts for this model. I saw this broken Acer S271HL bid monitor on craigslist for $30 and figured I'd give repairing it a shot. Fix is to run extra ground wire to that point. Via for ground to resistor divider of voltage feedback would heat up from nearby inverter components, and ground voltage would jump several tenths of a volt, triggering overvoltage and disabling LED strings until all were off. If the monitor still does not function properly, please refer to the troubleshooting section to diagnose the problem.Tl dr: LED driver board's vias were faulty and would gain tens of ohms when board heated up. Power-ON Monitor and Computer Power-ON the monitor first, then power-ON the computer. Connect one end of the adapter to the monitor and the other end to a properly grounded, AC outlet. Make sure both the monitor and computer are powered-OFF. 1-3 Connect HDMI Cable (Only HDMI-input model) a. Connect one end of the 24-pin DVI cable to the back of the monitor and connect the other end to the computer's port. 1-2 Connect Digital Cable (Only Dual-input model) a. Connect the VGA video cable to the computer. To install the monitor to your host system, please follow the steps as given below: Steps 1.

Acer s271hl manual