99 Mercury 200 EFI ignition coils

[92racing]

I read a lot on this forum and have learned a lot thanks for all the knowledge you share on the board. I have a 99 Mercury 200 EFI (OG826643) that I just put a new power head on which has about 20hrs. Motor is has been strong and responsive until the last couple outing. Just a little background I installed new power head, all new CDI electronics (stator, trigger, switch boxes, coils and regulators. Sent the ECU to CDI to have reworked fuel pump drive was bad. Also installed new interstate marine battery as well. Its been running fine until last weekend 3 of the six coils (#1,#2 and #6) went out they would fire sometime. Now today another coil has went out (#4). While checking the DVA voltage on the coils I did notice they only read 129-134 volts on all coils (spec 150v). I told the technician the voltage reading and he said sounded low but didn't give explanation.I sent the first 3 back to CDI and they replaced them with no hassle. Now I have to get this one changed out. While trying to find the problem when the first coils went out I went ahead and check all the electrical components to make sure something else wasn't going on.
I checked the following: stator- ohm and dva good
trigger-ohm and dva good
coils- ohm and dva 129-134 low
plug wires-ohm good
NGK BU8h plugs
I also have checked all my grounds actually brushed all when I assembled motor since I know the importance of this. I also checked for voltage on the ignition stop circuit and never seen over .003 volts cycling key.
I ended up putting all my old mercury coils on this evening and she runs like new again. Checked DVA voltage and they all read 168-174v.

So here is my question did I get a bad batch of coils or what can take these out. Can a bad switch box take out coils? I am at lost of what to do I have never had issue s with CDI electronic in the passed. I hate it was a lengthy post but I figured all the details are needed to resolve this problem.
thanks again for the help.

[tlwjkw]

I ended up putting all my old mercury coils on this evening and she runs like new again. Checked DVA voltage and they all read 168-174v.

this is tha right answer.. never have seen any other electric part (stator, trigger, switch box) take out a coil.. I can't remember anything good with cdi parts when I tried them.. but was several years ago.