Let me go over my situation over the weekend, in which 8 64 LED Pro's kicked ass, ran fantastic and the bands ALL loved them. Rn by MyDMX, by the way.
Circuit A: 2 KV2 Audio EPack 2500's with an S 1.0 top and an ES 2.5 bottom. 500-watt PA, rang great. Basket-ball/high school gym shaped/sized room. Way too much power.
Circuit 2: 5 Mackie SRM450's(first versions, Italian made), 1 Mackie SRS1500A sub. These were monitors.
Band backline, 2 guitar amps(100-watts each). 250-watt bass rig. One bad brought in 4 Par56's and ran those too.
My 8 64 LED Pros also ran off this circuit.
No problems. NO PROBLEMS with any gear.
DMX signal chain:
MacBook Pro running Bootcamp 2.1, XP Home SP3 on PC boot. 3-foot DMX cable to:
Elation OptiBranch/4 splitter.
200-foot DMX cable to stage. 10-foot cable to first light. 3 3-foot cables between the 4 lights in the first tree. Out of fixture 4 in tree 1 is 50 feet of DMX cable, then 3 3-foot cables between fixtures and a DMX terminator.
I made the DMX terminated. All cable is Accucable. 2oo-foot run ran along side my 200-foot whip(56 channel audio cable), 200-foot CAT5 for AVIOM system, 100-foot power cable from FOH(on another circuit) and 100-foot CAT5 for video.
Again, let me repeat:
No problem.
I suspect a bad circuit, a motor on the circuit, or even too much draw on the circuit.
Might be other issues. If they are flickering, perhaps do you have them in a strobe mode? Is your DMX configuration on the lights correct? Have you tried to isolate it down to 1 fixture?
You're not plugging the 64 LED's into the dimmers, are you?
Start looking for your bad cable and check the status of the terminator and ensure it is not problem. Also, keep your DMX cable away from power cabling as much as possible, crossing at right angles only when absolutely necessary.