no dash lights

On the circuit board where the main plug connects occasionally has a solder problem. Remove the panel and check the pins. Get a car battery and some small jumpers. Find one of the cluster bulbs (not an indicator like a signal) and follow both sides back to where either the pin is and/or a main panel ground. Connect the jumpers to these two pins (use some white out on the circuit board to show you where theses are for later). If your lights work then it is a connection problem.
If the lights work reconnect the wires to the cluster. Now find the dots of white out and with the test light connected to a good ground probe the back of the plug that lines up with your positive pin if you have power the problem should be on the ground side. To make sure connect the test light to a good power source on the fuse block and check the ground you marked with the white out. If the test light does not come on , it's the ground. (Just a thought: do all your gauges and indicators work ok?)