The output is powering a backlight for a display (part number: COM24H2P39ULC from Ortustech). After noticing that the display suddenly blacked out and came back on randomly, I found that when I touched the feedback resistors or breath on them, the output voltage dropped. Breathing casued a voltage drop of up to 1V, and touching them up to 3-4V. Using a wet finger was the worst. My first approach was to do the same test with the evaluation board TPS61220EVM-319. Same result there, so I change the value of the feedback resistor divider on the evaluation board (see picture1) to R1=100K and R2=10K to be more immune to noise, and it helped a lot, but still it is affected by heavy breading with 0.2V approx. Another solution was to apply hot melt glue on the whole power circuit, which solved the problem completely (not sure about later problems with that solution though). However, the new resistor values made it pretty stable, but I hope you could tell me that these values are good choice or not. Is there anything that I may have overseen by using such low values compared to what the datasheet say? (I know the current will increase some, but that is OK for me).
Picture 1: Evaluation board.
Picture 2: My design.
