Grrrrr
09-04-2016, 10:55 PM
Outdoor unit- 4mxs32gvju
3 * indoor units- ctxs12hvju
A little backstory,
System has been in for 3 years, worked great for 2 years. Unit 1 in the bedroom started giving an occasional u4 error starting about a year ago. Cycling the system power usually fixed it. About 6 months ago the power cycle stopped helping and now it's always flashing led with u4 error. The other 2 indoor units have continued to work with no problems since installation.
The service monitor LEDs on the outdoor unit indicate all is normal there (flashing green with none of the Reds lit up).
I put a temporary communication line in (terminal 3) to make sure the line had continuity and it wasnt a wiring issue. No change.
All ac voltages on the outdoor units wiring terminals a-d are the same for each set. The dc voltage on the communication line for the 2 working indoor units fluctuates between 0v and 35v. The dc on the comm line for the unit that's not working and the terminals that are not hooked up are both at a constant 70v.
How do I determine whether it is the indoor pcb or outdoor pcb that needs to be replaced without an oscilloscope to check waveforms. Or is there any other tests I can run or checks I can do to make sure that I am replacing the correct part.
I am tempted to swap the pcb from one of my working indoor units but am concerned I may damage it if there is an issue with the outdoor pcb.
Any input or advice would be appreciated.
Thank you
3 * indoor units- ctxs12hvju
A little backstory,
System has been in for 3 years, worked great for 2 years. Unit 1 in the bedroom started giving an occasional u4 error starting about a year ago. Cycling the system power usually fixed it. About 6 months ago the power cycle stopped helping and now it's always flashing led with u4 error. The other 2 indoor units have continued to work with no problems since installation.
The service monitor LEDs on the outdoor unit indicate all is normal there (flashing green with none of the Reds lit up).
I put a temporary communication line in (terminal 3) to make sure the line had continuity and it wasnt a wiring issue. No change.
All ac voltages on the outdoor units wiring terminals a-d are the same for each set. The dc voltage on the communication line for the 2 working indoor units fluctuates between 0v and 35v. The dc on the comm line for the unit that's not working and the terminals that are not hooked up are both at a constant 70v.
How do I determine whether it is the indoor pcb or outdoor pcb that needs to be replaced without an oscilloscope to check waveforms. Or is there any other tests I can run or checks I can do to make sure that I am replacing the correct part.
I am tempted to swap the pcb from one of my working indoor units but am concerned I may damage it if there is an issue with the outdoor pcb.
Any input or advice would be appreciated.
Thank you