I am using the below schematic to drop voltage from 5V to 3.3V (1117 3.3V - http://www.farnell.com/datasheets/2100276.pdf?_ga=2.141255921.210515873.1532314816-790306462.1508240417) for a Wifi Micro-controller and after few weeks of usage it started producing some high pitch sound.
Upon evaluation I noticed that after few minutes of powering the circuit, the output voltage increases from 3.3V to 4.8V and keeps varying drastically. I have checked all component connections (dry solder, short circuit etc) and everything seems to be fine. The power supply is rated 5V 600mA and the MCU takes 300 ~ 350 mA max during peak operations.
I finally had to change the LDO 1117 and its output capacitor (changed C4, 22uF to 100uF) though I am not very sure if its the LDO or the capacitor which failed (during the LDO replacement, the output capacitor got spoiled and hence I couldn't test them separately). Now the noise is absent and output voltage seems to be stable (3 days continuous operation).
As shown in the schematic I am using multiple MLCC output capacitors (as required by MCU). Would this have caused any issue?