Power to the coils [ positive 12 v.] comes from fuse # 6 and goes through the OVP.
When it will not start, give fuse #6 a light twist in its holder
and retry....
The way the coils fire is a switched ground. This is controlled by the ecu circuit [ with the crank sensor signal, etc.]
This ecu ground completes the coil circuit on the Neg side of the circuit.

But if you have no Positive 12 v to the coils [ all 3 positive feeds are tied together [parallel], then the feed fuse /ovp circuit can be the fault. This can be tested with a simple meter/test lamp at the coils input wire for 12v+. [ w/key on]
I have read that the coil feed wire on the later 104s has had bad solder connection where the 3 wires solder to the main feed for distribution to each coil in the harness...[ and possible bad harness, though I would think that the have already looked at that]

I also think that when they tell you there is no power to the coils , they are more likely talking the complete circuit , vs power feed.....but if it is just feed ,a power test for intermittent fuse
connection is a possibility... [ or ovp/fuse/ign sw. ]