SmallHD 5" monitor backlight issue (TPS61180)

[webhdx]

Hello
I accidentally connected 14.4V instead of 7.2V to my SmallHD 5" HDMI monitor. In the result the backlight is not working. It's based on TPS61180 IC: https://www.ti.com/lit/ds/symlink/tps61182.pdf

Here is the typical circuit:



In my case it uses 7.4V battery voltage. It's connected to the 5" LCD with 2 LED strips (each have 7 LEDs in series) so leftover 4 feedback channels are terminated with 10 kOhm resistors as the datasheet recommends. I replaced the TPS61180 which seemed to be the first suspect. After replacing it I now see a quick backlight blink. The voltage on Vo is 7.4V when the monitor is in standby and it's around 14V when it's booted. I've checked the panel itself with different backlight circuit and it works (I also confirmed the monitor itself is fully functional). I also did a quick contraption with 2 rows of 7 LEDs in series and the effect is the same - one blink and it's off. I did a lot of research and to me it seems like this is some kind of overvoltage protection going on:



Which is weird since the LEDs in the backlight seem to be working, also leftover feedback channels are properly terminated.

I hit the wall - I have no electrical engineering knowledge around switching voltage regulators/backlight circuits. Can you point me what should I check next?

Thanks in advance!

[Miti]

Considering that the IC can take up to 24V, it would not be my first suspect. Have you checked the EN and PWM Dimming inputs? Is it enabled? Does it have a PWM that can be adjusted from brightness, I believe? There must be a processor that controls it and that would be my suspect.

[techneut]

Did you check the 2 led strings and their connections and the 10K resistors, the TPS61180 will shut down of one of the LED strings has een open. Check pin 16 (Fault) should be low.