Im studying this board's circuit. But cannot find what's this P527 DGM component is. Could anyone tell me? Thanks
It is a TVS diode from the Chinese company BrightKing. It appears to be a clone of the Littlefuse SMDJ64CA. The picture below shows a clip from the SMDJ page on the BrightKing website. Note the matching logo on the part.
Here is a link to the BrightKing SMDJ datasheet.
Below are clips from the datasheets showing the specs for the parts. LittleFuse is in green followed by BrightKing in red. Note the package marking code DGM for the bidirectional part. For small parts, manufacturers often use marking codes, since the full part number does not fit.
I don't recognize the manufacturer logo, but the SMD marking (DGM) and the package (DO-214AB?) point to it being some kind of transient voltage suppression (TVS) diode.
Probably something like this:
You can use a multimeter to check if it's unidirectional or bidirectional.