CDI, which diodes are these?

[RempageR1]

Hi,

I`ve got a CDI that I am trying to fix and as you can see, all the normal diodes (not the zener ones) have been corroded away. Who knows what kind of diodes these are and what modern-day replacements I can use?

Thank you!

 

[satariel666]

As far as I can tell You those are schottky diodes.
I was never sure what amperage they are so I always replace them with 10A ones.

Most defo You will need to replace the main transistors(darlington's).

 

[RempageR1]

As far as I can tell You those are schottky diodes.
I was never sure what amperage they are so I always replace them with 10A ones.

Most defo You will need to replace the main transistors(darlington's).

Thank you for your reply.

Why do you think the transistors are also fried? Do they go when the diodes fail or so?

 

[jfeagins]

Don't capacitors dry out and begin failing with age too? Are you replacing them as well?

 

[RempageR1]

Capacitors should still be fine. The CDI in my max is also 25 years old and still going strong.

I`ve been searching for 10A schottky diodes but fail to find any with the same housing doing 10A. Satariel, do you have a link where i can get them?

Thanks!

 

[satariel666]

If diodes gone bad then 100% guarantee the transistors are bad.
I tell You something funny - You will never buy those transistors in EU...
Im not sure if ETD41 transistors are avaible anywhere? :ummm:

There're 2 replacements: MJE5742 and NTE2317.
Again funny...they're also not avaible in EU.
Well, I was unable to find them.

MJE5742 are avaible in USA, last time when I was rebuilding that TCI Sean helpd me to get them.

This is typical issue with this TCI.


Capacitors should be fine, they rarely go bad.

Rempage,
Im not sure where You could get those diodes close to the Pays-Bas.
Im bying them localy witth NP.

Maybe try ELFA Sweden?

 

[RempageR1]

Satariel, thank you again for helping me!

The MJE5742 is actually avaiable here: http://www.okaphone.com/artikel.asp?id=464787 so that shouldn't be a problem. Finding the schottky`s is a little harder. Haven't been able to find them in the same housing as original, I can only find them up to 5A like these: http://www.okaphone.com/artikel.asp?id=468342

The search continues....

 

[satariel666]

No problem.

I was unable to find those transistors in EU.
But You've an luck and Ya did find them.
Thats cool, thanks.
Altough a bit pricey there.

I think You should know this but I will mention that darlington transistors cant be
check like normal transistor.


As for the diodes.
I was never sure what exactly that diodes are.
I perform 5A test on one good diode from TCI and it survives.
Was a bit warmy but nothing dramatic.
I think You can try to use that 5A and see what happens.
If they get warm that means You likely need stronger ones.

 

[RempageR1]

Thanks again. I will discuss this with the guy I am repairing this unit for to see if he wants me to order these parts.

If so, i`ll let you know how it worked out!

 

[hexec]

digikey should have everything you need. digikey is a world wide electronic component distributor. make sure you change the country on the top right of the website.

For Netherlands go here.....http://www.digikey.nl/

The diode and transistor can be found there.

 

[88vmx12]

try Digi key I just received their catalog. It has to be 4" thick!

 

[hexec]

There's also Mouser Electronics. Just like the digikey website you have to select your country in the top right corner of the website.

http://www.mouser.com/

 

[satariel666]

Yep, digi and mauser are good supliers.
Great choce of parts they have.

But as its goin with all international supliers.

You will find many so called dealers in many countries.
Proud list of dealers they have on thier website.
When You finaly need something and You are starting to ask them:

Do You have XXX on hand?
Yes sir, right here ready to ship in a very good price.
After 3 weeks later You are geting nervous why You still not recived what You've ordered.
The truth is that they had "big shit" in stock.
They ordering all from origin manufacter country.

LOL LOL this way I can oder what I need myself and can get in in 1 week.

 

[hexec]

wow, that's not good. I'm sorry to hear that. Too bad there wasn't a better way because these parts should be easily acquired. Have you ever ordered anything from the US or Canada? How long does it take? I'm more than willing to be a ship forwarder for you. In other words, order what you need and have then deliver to me. When I receive the order I can turn it around and ship it to you. I little more on shipping but it might be faster than 3 weeks.

 

[satariel666]

No, its all good.
Thanks.

Im ordering the stuff around the world all the time just right becuse I hate to be cheated!
I was never been cheated abroad(ok once with CMSNL).