1996 Golf Starting Problems

I have a 1996 Golf that will not start. It turns over fine but there is no spark. The dealer replaced the coil, cap, rotor, distributor and crank position sensor and it still has no spark. They also tried an ECM from a running car and it still has no spark. They said they do not know what to do from here. Any ideas out there?

Did they check the ECM power supply relay? It's in position #3, second row above fuses, third from the left.

Did they check the ECM power supply relay? It's in position #3, second row above fuses, third from the left.I will check the relays to see which ones are new, they replaced three of them but did not say what they did.