Denon AVR-X6400H Service Manual page 88

(15) Are a picture and sound output when a dif-
ferent TV is used?
NO
Check the unit.
Check the Firmware.
Is "IP SCALER ERR" displayed?
See "HDMI "Rx/Tx" Failure Detection"
YES
The TV is faulty.
NO
Check the circuits around the IP SCALER [U2800,
DIGITAL PCB] and DDR2 [U3000/U3001].
If there appear to be no problems, [U2800] or
[U3000/U3001] is faulty.
88