Transmission Processor Hardware Error - Mitsubishi Electric PUMY-P250YBM Technical & Service Manual

Check code
6602
(A2)
Abnormal points and detection methods
If the transmission line shows "1" although the transmission processor
transmitted "0".
●Diagnosis of defects
Make sure to turn the power OFF before connecting/disconnecting any connectors, or replacing boards.
A wiring work was performed
while the power OFF.
Turn the power back ON.
Does it operate normally?
OCH760

Transmission processor hardware error

Diagnosis
Yes
Yes
Causes and checkpoints
A transmitting data collision occurred because of a
wiring work or polarity change has performed while
the power is ON on either of the indoor/outdoor unit,
Fresh Master or Lossnay
Malfunction of transmitting circuit on transmission
processor
Noise interference on indoor/outdoor connectors
If the wiring work was performed while the
power ON, turn the power OFF of indoor/
No
outdoor unit, Fresh Master or Lossnay
simultaneously for 2 minutes or more, then
turn the power back ON.
Replace the indoor/outdoor controller board.
No
There is no abnormality on the AC unit.
It might be caused by an external noise, so
check the transmission line to remove the
factor(s).
75
Remedy