Evinrude Outboard Ignition amplifier - Page 1
Forum section: electronics / repair

author: planenut2000
author_rank: Contributor
timestamp: April 08, 2025, 10:41:45 pm
content: I have a 1969 Evinrude 4 cylinder that uses a 12v DC, points triggered ignition amplifier(CD box)! It is supposed to be able to feed the ignition coil primary with between 200- 400volts. It quit working, it has the 12 volt input but no output to the coil. I have opened the box up and boiled it enough to pick most of the potting compound off. I desoldered a 470uf/50v cap and tested it as open. But there are 2 transistors on the back of the board are suspect also! Can anyone tell me for sure how to test these? I used the diode function on my fluke so far, just not sure. i have attached a few pictures of what i'm working with!

author: amyk
author_rank: Super Contributor
timestamp: April 08, 2025, 11:24:28 pm
content: The first one is aBDT63A, second one I'm not sure of the exact part but it's a Teccor product, should be an SCR of some sort. Might be S6016R.

author: planenut2000
author_rank: Contributor
timestamp: April 09, 2025, 12:10:22 am
content: Thank you for the help! Is that teccor S616 an outdated part number? Is there some way check for sure what that number was superseded to?

author: floobydust
author_rank: Super Contributor
timestamp: April 09, 2025, 03:46:55 am
content: I think it's a house number, the "HH" on the tab might mean the part is selected. It's an SCR and there should be two? This drives a 4-cyl engine, wasted spark, two coils?Typical CDI like this has a couple power transistors for the DC-DC converter from 12V to high voltage, say 300VDC. If one of these fail, usually a transistor shorts, it should pop the supply fuse.There should be a high voltage capacitor as well to check. I wonder if you can power it up on the bench and see if the DC-DC is alive and making high voltage.Test the S616 as an SCR see how it does. The transistor in the pic has a '92 date code I think so the module is newer.If you post more pics, no matter how ugly I can tell what the circuit is.

author: planenut2000
author_rank: Contributor
timestamp: April 09, 2025, 11:35:32 am
content: Hi, Due to some rough handling the transistor broke off the board, but i know the proper location to reinstall new ones. The 470uf capacitor is open

author: floobydust
author_rank: Super Contributor
timestamp: April 09, 2025, 06:02:18 pm
content: I usually suspect solder joints, the power semiconductors, the capacitors in something like this. CDI usually the SCR bags or DC-DC converter transistor or the HV cap.It's weird the 470uF cap went open, it's for filtering incoming 12V power so this should still have worked, made spark but maybe cutting out. All the parts in this are good quality, many 1992 date code. Nothing looks burnt or cooked.Check the 1uF 500V yellow film cap, you can just lift up one leg on it - after making sure it has no stray charge with a multimeter on DCV. It should be discharged but remember that if you ever power this up on the bench that the cap can bite. See if it has gone low value giving a weak or no spark.I'm not sure how you want to troubleshoot this - some people just replace parts, some will check each part, others will power it up on the bench.For now, I would keep testing parts until we find the dud. There are a few power diodes to look at.Unfortunately I can see there are some parts located under the transformer, they sure got cute trying to make this small.I can see several fractured solder joints, they have the telltale ring so I would look at the board with a magnifier and retouch them.Another trap is the board seems to rely on the mounting bolts being grounded - but I don't know the wires what they connect to.

author: planenut2000
author_rank: Contributor
timestamp: April 09, 2025, 08:06:21 pm
content: Thanks For your input! The 2 transistors in my first pictures are the 2 that were on the back of the board. Im not sure how to test them! If i use my diode function from the center pin to the outer pins, i get .6volt on one leg, but from center pin to the other side i reads nothing, The 2nd transister won't give me any volt reading from the center pin to either outer pin. But those 2 outer pin have continuity between them.The yellow film cap you mentioned, is that next to the big transformer?

author: planenut2000
author_rank: Contributor
timestamp: April 10, 2025, 12:09:55 am
content: I need to correct something! the 470uf cap is shorted and not open. When checking it with my meter i seen OL think it was open, but in cap mode i guess thats shorted instead.The large yellow cap you mentioned, i desoldered one leg and checked it and it read 1.0uf

author: floobydust
author_rank: Super Contributor
timestamp: April 10, 2025, 03:03:33 am
content: BTD63A NPN Darlington transistor 80V 10A 90W hFE>1,000 at 3A, used in the DC-DC converter. Pinout B-C-E, tab is C.Alternates: TIP142T looks best. Lesser match is BDW93C, BDX33B or BDX33C, depends on what you can get.These parts are awkward to test because they have built in E-B resistors and an extra C-E diode that gets in the way and causes confusion.On Ohms function, (with the part out of circuit) I would expect open circuit between C-E and maybe 8-10k E-B. Open circuit C-B.On Diode-Test function, I would expect open circuit between C-E with C(+) and E(-), but a diode seen C(-) and E(+).A shorted part is easier to ID. It better mount to a heatsink for cooling!-----------------------------------------------------------S616 Teccor SCR - no data on it. Might be a hand selected (for sensitive gate) "HH" stamped on tab.S6016R600V 16A but these have a wide 1-30mA spec for gate sensitivity. Littelfuse bought out Teccor.Is the tab isolated on the SCR, or the middle pin connected to it? Pinout K-A-G, tab A or isolated.I would consider as a replacementSV6016L2TP600V 12A 5-10mA, is isolated tab. Or TN2015H-6I 600V 20A 6-15mA (isolated tab).-----------------------------------------------------------If that cap shorted it might have killed the big diode connected to the purple (12V power?) wire, and it should have blown a fuse somewhere... going to the ignition switch maybe.The 1uF cap seems OK.

author: planenut2000
author_rank: Contributor
timestamp: April 11, 2025, 07:26:34 pm
content: Im in a holding pattern for a couple days on this project!

author: planenut2000
author_rank: Contributor
timestamp: April 20, 2025, 02:20:45 am
content: Sorry for the Delay!The S616 tested with an ohm meter shows no continuity from any terminal to the tab, and switching the leads on the ohm meter has the same results

author: planenut2000
author_rank: Contributor
timestamp: April 20, 2025, 03:02:17 am
content: Do you have idea for a suitable replacement for a Nichicon 470uf/50v VX(M)?

author: MathWizard
author_rank: Super Contributor
timestamp: April 20, 2025, 05:00:30 am
content: So did you boil the whole potted PCB in a pot of water ? How long do caps and wires and stuff last in that I wonder? Well I better not go boiling caps in my cooking pots, but yeah someday maybe I'll try it outside in an old kettle. I took apart a potted relay once, and broke the glass, I should have tried boiling it.