Denso BHT-1306BWB User Manual page 142

BHT-1300B series
10.
Press the ENT key.
A 1-dot thick frame is displayed around the screen.
Press and hold the BS/C key to return to the previous screen.
Press and hold the BS/C key, or press the SF key and BS/C key
simultaneously to return to the TEST menu.
11.
Press the ENT key.
The speaker sounds once, and the display returns to the TEST menu.
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