LilyGo T-SIM7080G board damaged by humidity ?

[mathieucarbou]

Hello,

I am testing the lilygo board outside since a few days. There is a lot of humidity outside, the lilygo is in a waterproof box (but the box has a hole for the wires on the side, so the air can enter but not the rain).

I am wondering what's this on the board ? it was not there before. It feels like the humidity stats damaging the board ?

The connected usb-c device is this solar panel : https://fr.aliexpress.com/item/1005005509831452.html

• Tension de fonctionnement: 5 ~ 5.5V
• Courant de travail: 0.8A ~ 1A(Max.)

[lewisxhe]

Obviously it is affected by moisture. You can remove the damaged original parts first, then power on and test whether they can work.

[mathieucarbou]

Obviously it is affected by moisture. You can remove the damaged original parts first, then power on and test whether they can work.

I don't have the tools for such precise work at home. Right now, I can power the board with USB-C, solar panel connector does no work, and I can power through internal battery.

But I found that when I have a USB-C solar panel connected and internal battery, when the solar panel is not able to produce enough current, the device shuts down instead of switching to the battery.

I do not have this behaviour with the second board.

I have ordered a spray for electronic boards...

But what I don't understand is why these boards come without any varnish, silicon or resin to protect the components from humidity / moisture ?

Also, is there a solution I could do to cleanup without having to remove the components ?

How I could check if some are damaged ?

[lewisxhe]

Damaged capacitors visible to the human eye can be removed first and then replaced according to the parameters provided below

[mathieucarbou]

@lewisxhe : do you know what kind of product I could use to cleanup and remove this blue-green mixture ? isopropyl alcohol ?

[mathieucarbou]

I was able to clean the board with some isopropyl alcohol and I can power it through USB-C and battery, so even if some PMU settings have been affected it is stil usable for some other projects.