Like Chris is saying, bad connections at any point between BR2 and C5 will give you major problems. The image below shows the topside circuit trace (Violet dashed line) and the layer transition point under C5.
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There are, and many are of them are of poor quality ... I actually have mixed feeling on this subject as while I would love to purchase parts manufactured to original specs from whomever holds the mfg. rights, the facts are that many of these parts are only available as counterfeits coming out of China. Many times these are the only parts available and the way I see it is it's better to have a part with a high failure rate then no part at all. I spend more time that I'd like to admit searching for NOS parts from the '90's.