Thunderbolt Display goes black few seconds after startup

[jks067]

I have a 2011 TBD that will display an image for just a fraction of a second prior to going to a black screen. -- I can make out my background image just prior to it going black.

The display is recognized by system information even while the screen is black and the display will play audio from its internal speakers.

The TBD had AppleCare on it until 01/01/2015 and I am currently in talks with a senior advisor on getting a CS code for the display.

If I am unable to obtain a CS code I would like to attempt to repair the screen myself as I am an ACMT, ACSP and EE student that can't afford spending $900 to replace a display that is only three years old. I mean, I have a Cinema HD Display from 2007 that works great still to this day!

Has anybody else experienced this issue or have suggestions on repairing the display? My first guess would be an LCD panel controller board.

 

[FuNGi]

It's probably the wire connecting the to the LED's. I had the same symptoms and took mine to a certified tech. They fixed it in 2 days after diagnosing and waiting for the part to come out n from Apple. Fix it. Don't buy a new one.

 

[jks067]

Well, I am an Apple Certified Macintosh Technician and I work at an Apple Authorized Service Provider. I have looked at many of these displays before but never had any issues out of mine; until now that is. I have opened it up and tested the voltages coming into the logic board from the PSU, 3.3V bus is good but the 12V bus is reading 8V. So I have ordered a replacement power supply from Apple through work. We shall see if the replacement PSU fixes the issue as it appears as though the 12V bus feeds the LCD; which if the 12V bus is only feeding 8V then I would expect erratic behavior from the panel due to the under voltage.

If the issue persists with a known good PSU I will look into scavenging a display from an old 27" iMac that we have laying around the shop.