Chosen Solution
The screen does not power up after plugin it in. The led flickers and there is a chirping sound. After some time it turns on. I concluded it might be an broken capacitor. I found a broken one on the board and replaced it.
The other capacitors seemed to be ok(checked using Multimeter measured capacity). The replacing of the broken capacitor did not fix the issue. Afterwards I started checking the voltage regulators. I measured the voltages after plugging in the power supply until the board switched on. There are three Voltage regulators on the board: Power supply: 19.5VMP1484: 5VG1084(LT1084 replica?): 3.3V912T45: 1.2V The 5V regulator provides only ~4.5V after connecting the power supply. The voltage jumps a little in intervals and after some time it provides steady 5V. Before that the 3.3V regulator cant provide its voltage as well. Video of the power up - Measuring 5V and then 3.3V I think next step should be replacing the 5V regulator or are there any other suggestions?
Which cap did you replace? I desoldered & measured the 220uF/16V directly above MP1484EN, and found the capacitance has dropped to 185uF at room temp. If you aim a hair dryer at it, the board stops blinking and powers up immediately.
Replacing the following two capacitors I fixed already three screens of this type.
X-) Thank you for your help again lonnie.chang!
