Re: NEC MultiSync V552 power on and off (E-Waste Dumpster Diving)

I "fixed" it by connecting the VFB2-2 and VFB2-3 to VFB2-1.
This way the backlight driver does not "see" the rising voltage across the led strips 2 and 3 and keeps working.

Only downside is that you can now visually see that in the upper right corner the backlight is a little dimmer.

Re: NEC MultiSync V552 power on and off (E-Waste Dumpster Diving)

Okay after doing some more measurements to check what @tom66 said;

All of the VFBX pins (the negative side of the leds) are measuring 0.5~ish V.
Except 2, VFB2-2 and VFB2-3. VFB2-2 measures 6.2V when the TV is cold and 6.3 when its gets warm. The VFB2-3 pin start around 9.1V and rises until 9.2V when the TV gets warm.

At VFB2-3 = 9.23~V the backlight driver shuts down and the backlight stops working.

Is this due to failing backlight LED's? Would this mean that I need to...

Re: NEC MultiSync V552 power on and off (E-Waste Dumpster Diving)

There is an ERR pin that runs from the backlight module to the powerboard, where it is directly connected through to the mainboard.

What seems to be the problem -> backlight module shuts down after 10 min and reports an error -> mainboard resets the powerboard and this cycle happens over and over again.

I monitored the 24V to the backlight module during this "shutdown" -> no change, no dips nothing. The output voltage from the backlight module just suddenly drops from...

Re: NEC MultiSync V552 power on and off (E-Waste Dumpster Diving)

I've got the same problem here.

+110V backlight is good.
+24V line is steady and good
+12V line steady and good
+5V line steady and good

Fused are all okay

Monitor boots up, shows source (HDMI) for a second, then flashes green, then shuts down and this cycle continues for 10-15 seconds. After that the main relay is disconnected and red light flashes 2x and repeats this "error code"

The service manual does not really provide...