Power Pack repair attempt but cant discover parts

[BurningTantalum]

Hi Orbanp,
My pics were just an example of what I consider to be a simple way to draw out a component layout, then from that a netlist then a schematic from what is a messy PCB due to the potting compound. It wasn't meant to be a diagram for Florek's module.

As I said before, I have not seen this type, but I wonder if it could be a replacement module by 'Sierra' or CDI Electronics', both of whom supply parts for older OMC motors. Original parts are quite hard to come by now, and second-hand CDI units are usually in a poor condition due to the rubber covered wires.

Florek - Before you get carried away with re-inventing the wheel, are you sure that the ignition coils are OK?
Is the output from the high-voltage magneto coil OK?
Is the output from the trigger coil OK? Both the above measured with your DVA meter, or a diode and 1uF cap to store the peak.

The 'daughter' PCB with the conformal coating looks odd and will be a nightmare to draw a schematic.

If all else fails it may be easier to find an old or dead CD2 unit that looks like the ones we are familiar with, and repair that. As far as I know all the 2 cylinder motors from around 5hp up to 40hp used the same CD2 unit.
Regards, BT

[Florek]

Im sure engine is ok since i borrow cdi from friend and it worked. Andmy cdi on his engine give the same weak spark. Anyone know what can be this second pcb that vertical one? What it do? Below the coating dor sure i see some zener diode and some microcontroller.

[BurningTantalum]

Hi Florek,
Things are a bit more clear:
https://www.outboardignition.com/page40.asp

I am still not clear which motor you have, as we don't have an HP size and definite year date BUT- You show that the CDI unit has 'CD2' written on the outside. The picture of the PCB clearly shows 'CD3' written in the mask.
According to the info in the link above, the CD3 module (which I have never seen so know nothing about) seems to have an optical trigger system.
This would explain why you have 3 wires from the 'trigger'.
This is completely different to the CD2 unit that I am very familiar with.
Much of the comments and suggestions in previous posts from me and others are thus not really relevant.
Your pics show possibly three semiconductors (SCRs?) in a row, possibly suggesting a 3 cylinder unit. I understood that it was a 2 cylinder motor.

If you have rested all of the semiconductors and passives on the main PCB, then I would suspect something on the coated 'daughter' PCB. You don't stand much chance with this unless you can get rid of most of the coating.
I suspect your motor is later than 1994 and may have the 'limp home' feature, which uses a thermo switch on the motor.
Can you find the model number on the motor?
It is usually on a plate on the clamp part, but can be repeated on an aluminium core plug on the cylinder block (AFAIK).
Regards,  BT

[BurningTantalum]

I have just looked again at the link - I must get some new reading glasses! The CD3 unit has been fitted on some motors since 1979. Only some were optical trigger.
I don't know why I have never come across one, but this is only a hobby interest to help friends etc.
Sorry, BT

[Florek]

https://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1996&hp=50&model=BJ50BELEDS
This is my engine
it seems like it use optical sensor, but on other website its says that optical sensor was used on 4 and 6 cyl engines , and mine have 2 cyl. Any way if it have optical or no, cdi somehow must know when to give spark so optical or normal trigger coil must generate some V , so it doenst matter what sensor my engine use since, this cdi schematic should work since it give V to trigger scr to relase power from capacitor. My engine have 3 wire from trigger/optical sensor white blue green, and acording to this info seems like it should give 100-400v and any other version of engines should give 0.6V+ so even if my engine have optical sensor it still should work with that cdi schematic below

[BurningTantalum]

OK, thanks for clarifying that. Lets take a moment to review what we now know:
It looks as if your module is NOT an optical trigger type. This is good.
If your drawn schematic is correct, then the circuit is the same as the CD2 units that I am familiar with.
The info in the list shows that this module has the 'limp home' facility (I think it operates to limit RPM when the motor overheats, such as water pump blockage) This must be the function of the 'daughter' PCB, and because there is some kind of spark we can assume that it is not faulty.

I think that there is an error on the list, that states the trigger coil output as "100 - 400V". This is obviously incorrect. This is the voltage from the charge coil. The open circuit voltage from this coil will be in the region of 5V or so. If connected to the unit it will be the volt drop across the gate to cathode of the SCR - less than 1V.
I would suggest:
Disconnect the 'kill' switch and /or the safety lanyard switch. These are notorious for being full of water and rust. It could be leaking away voltage from the capacitor.
Can you measure the voltage on the capacitor, either with an oscilloscope or with a DVA when the motor is turning?
If the voltage is low, then it could be the Triac.
I am assuming that you are spinning the motor with the electric starter. Remove the plugs to make this easier on the battery, BUT don't forget to connect the plugs to the leads AND a ground wire to each plug body (thread) to a good connection on the motor casting.
Note: Any spark plugs will do, from a car etc, as long as they work !  Then these can be kept for testing, and the correct plugs will be ready to reinstall for running.
BT

[Florek]

Today i win the war. Have 2 strong spark. After replacing scr. BIG thanks for everyone who was involved for helping me out

[Florek]

according to this schematic this triak and varistor should cut the voltage if coil provide more than lets say 400V, but how? the varistor will blow off or what?

[Florek]

hello again can someone know what is this broken piece? its have shape similar to rugby ball and blue strap

[4cx10000]

It looks like a SOD-64 package, a diode anyway, whether it is a rectifier or zener diode do not know. You will have to remove it in order to see if there is any identification. Here is a data sheet with a diode with same package: https://www.vishay.com/docs/86003/by228.pdf

[Florek]

it is possible that its a avalanche diode? id is connected to cathode of thyristor thyristor is nec 3p4mh its rated for 400V, so i should buy avalanche diode for 400V ? if i understand correctly avalanche diode flow voltage in only one direction, but if breakdown voltage apply in reverse then diode also pass this voltage