Greetings everyone!

After 2 years of impeccable behavior my ’89 745T “has decided” to let me down overnight (hm… would it be a consequence of this hot, humid summer ? car is under tailor-made carport, the ’90 BMW takes the garage).
Since my currently overworked mechanic (who alas is no Volvo specialist) has no “insider information” besides electrical wiring, I turn once again after having checked the archive to bricksters for advice, if any of you had a similar misfortune on a 740 T of that age….

It cranks fine but no sparks : distributor doesn’t receive a signal…it seems to point out at a faulty Ignition Systems Control Unit or faulty “Power Stage” (is that what they call power transistors on other cars ? I suppose it strengthens the signal sent by the ICU).

Any other leads as to what should be further diagnosed, tested, explored ? or should I get first the “power stage” replaced (sounds like a hard rock group) ?? or get myself another ICU ?
any ideas very very welcome as I hope to bring this car to 300k like my Canadian friend (’90 745T) -- mine has “only” 205k and is a great family car.

Enjoy the week-end (those of you who have up & running Volvos)!