We often find badly drawn connections at our vistits. Most of them have gained a bad contact due to material subsidence, but sometimes the the connections are installed incorrectly.
The easiest way to discover a bad contact between accass points is to use a thermography camera.
Thermography is a quick and contactlessly way to measure the temptature rise at an access point with bad contact.
Servicepoolen i Stockholm provides thermography, troubleshooting and fixing of any fault.