Checked sink upstairs not draining. Tried to snake out drain multiple times and realized that it was a jack and Jill bathroom and the cable was just running to the other sink. Cut vent in attic and snaked out drain. Sinks are now flowing properly. Also let customer know that there was paint going down the drain and it should not be going down. Showed customer ac drain maintenance pipes in Attic so he could start maintaining the lines.