Air-conditioning unit power supply failing to power up
Hi all, I managed to narrow down which PCB was causing my Haier AC to throw out an E7 error code (E7 indicates that the indoor unit and outdoor unit cannot communicate). I found that the outdoor unit power board which gives 5v and 15v to the outdoor unit module board fails to fully power up.. The power Led starts to fade in incredibly slowly and the 5v and 15v power buses jump around like crazy and never reach their required voltage. I unplugged the module board from the power board and the power board powered up fine! It had a steady 5v and 15v out and the power LED came on instantly and Bright. I assumed that there was a short on the module board from this however I reconnected the 5v and 15v cable while the power board was still powered and generating stable voltages and to my surprise it didn't shut off and the Voltages were still stable and the Error code went away. It seems that If I attempt to turn on the AC with the power board connected to the module board the power board fails to turn on and generates unstable voltages, but If I connect the module board after the power board has finished powering up it works just fine.. Is this a symptom of a bad cap somewhere? What could be the cause of such a symptom?
Thank you.
Here is the service manual if it helps :
https://cdn.badcaps-static.com/pdfs/...2306ad82cb.pdf
E7 error description starts from page 61 and schematics of outdoor unit start from page 71
Thank you.
Here is the service manual if it helps :
https://cdn.badcaps-static.com/pdfs/...2306ad82cb.pdf
E7 error description starts from page 61 and schematics of outdoor unit start from page 71
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