This is the LED light circuit board that indicates the system's power, battery, and HDD status, compatible with the Dell Latitude 5420 Laptop.
Compatible Dell Laptops:
-Precision 3470
Latitude 5420
Latitude 5421
Latitude 5431
Latitude 5430
DPart Number: H4YYK
alt Part Number's:
Board: LS-K491P
Cable: 1G1MX; GDF40, NBX0002R100