Yamaha TW-E7B Noise-Canceling True Wireless In-Ear Headphones (White) - Manual (Page 14)

Turning on the power
Once you remove the earbuds from the charging case, the earbuds will turn on.
1
Remove the earbuds from the charging case.
The indicators light up as shown below, and the power turns on.
Blue
Lights up for 1 sec
NOTE
When an earbud is low on battery power, its indicator will flash red three times when the power is turned on. If this happens, charge
the earbud.
Related links
“Remaining Battery Power” (p.16)
14
Charging and Powering > Turning on the power