How about checking the port using a USB meter like this one [product|IF145-415]
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You might want to try first replacing the
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You might want to try first replacing the [https://www.ifixit.com/Store/Mac/MacBook-Pro-15-Inch-Retina-Late-2013-Mid-2014-I-O-Board-Data-Cable/IF117-039-1], then you’ve proven the issue is the [https://www.ifixit.com/Store/Mac/MacBook-Pro-15-Inch-Retina-Late-2013-Mid-2014-Right-I-O-Board/IF117-037-1]. Here’s the IFIXIT guide [https://www.ifixit.com/Guide/MacBook+Pro+15-Inch+Retina+Display+Late+2013+I-O+Board+Replacement/23394]