Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

cdi unit to a motorcycle

Jeffro

Newbie level 4
Joined
Jun 15, 2020
Messages
6
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
34
I have a cdi unit to a motorcycle thats over 30 years old that crapped out on me. I narrowed it down to the cdi as I have no spark to my ignition coils. I am not an electrical person by any means but I can unsolder and resolder components. My issue is that I don't know what I'm looking for. I've been reading that a bad SCR is what usually goes bad in these but I have no idea what it looks like. I see no bad solder joints either. Can someone please help me?20200614_193141.jpg
 
Last edited by a moderator:

BradtheRad

Super Moderator
Staff member
Joined
Apr 1, 2011
Messages
13,469
Helped
2,666
Reputation
5,326
Reaction score
2,571
Trophy points
1,393
Location
Minneapolis, Minnesota, USA
Activity points
100,708
This looks like the best bet to be an scr. You have two of them. Can you get at their solder joints on the other side? However it's too soon to remove them.

Tell us all the lettering on them. It can't be seen due to glare.
closeup cdi.jpg
 

Jeffro

Newbie level 4
Joined
Jun 15, 2020
Messages
6
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
34
Ah, those. Fuji 5N D1071
 

Easy peasy

Advanced Member level 5
Joined
Aug 15, 2015
Messages
2,482
Helped
912
Reputation
1,824
Reaction score
905
Trophy points
113
Location
Melbourne
Activity points
14,017
It doesn't appear to be CDI as there is no 500V storage cap, or step up power stage, just transistor assisted, after 30 years could be solder joint(s) or the transistors used to energise the coil ...
 

Jeffro

Newbie level 4
Joined
Jun 15, 2020
Messages
6
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
34
By the manual its called the ignitor.
 

Jeffro

Newbie level 4
Joined
Jun 15, 2020
Messages
6
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
34
Broken SMT part?
 

BradtheRad

Super Moderator
Staff member
Joined
Apr 1, 2011
Messages
13,469
Helped
2,666
Reputation
5,326
Reaction score
2,571
Trophy points
1,393
Location
Minneapolis, Minnesota, USA
Activity points
100,708
Several components next to the scr's appear to have black deposits. It's hard to tell if they're charred, or perhaps they attracted carbon particles. Can you confirm what it is?
There's a chance it results in unwanted current flow, causing malfunction.

By cleaning away the deposits you may get the unit to work again. The components are hard to get at. To clean properly is the big hurdle. It might be done with solvents, and/or brushing. Maybe even sandblasting.
 

Jeffro

Newbie level 4
Joined
Jun 15, 2020
Messages
6
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
34
Its actually just some goopy crap that is sporadically present and causing glares from the photo. This PCB was in a sealed plastic case until I opened it today. I examined all of the solder joints under magnification and didn't find any solder joint breaks or anything strange.
 

FvM

Super Moderator
Staff member
Joined
Jan 22, 2008
Messages
46,911
Helped
13,916
Reputation
28,080
Reaction score
12,562
Trophy points
1,393
Location
Bochum, Germany
Activity points
273,618
2SD1071, NPN darlington transistors 6A/450V, not SCR. I would at least check that they have no CE short. But it can be anything, e.g. dried out electrolytic capacitors.

Is it a two-cylinder, two-ignition coil configuration?
 

KlausST

Super Moderator
Staff member
Joined
Apr 17, 2014
Messages
17,422
Helped
3,937
Reputation
7,872
Reaction score
3,807
Trophy points
113
Activity points
115,509
Hi,

I wonder how an SCR can be used as ignition trigger.
Usually the coil gets activated current flow, ... end when released (switch open) high voltage gets induced to trigger the ignition.
But an SCR opens when there is about no current...

Klaus
 

Jeffro

Newbie level 4
Joined
Jun 15, 2020
Messages
6
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
34
Its a 4 cylinder bike with two pick up coils. Is there a place I could send this to and have it rebuilt?
 

Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top