AEAD 200-le idle control board repair

[k3500crane]

I have an aead 200-le that welds and works great. Didn't idle up when I got it, so with the help of some members here I got new scr's and replaced them. Now it idles up but never back down. It now it blows the printed circuit board line between d54 & r58. Soldered in an inline fuse in place of the line between d54 & r58 and it blows the instant the unit idles up. I know I can buy a new one but I like fixing things. Any ideas? Thanks guys

[weldonwelding]

I had the same problem with my aead. I also got the same advice, to replace the 2 scrs on the idle board but i went with buying a new board from miller. Everything works fine now. I have the old board but it has the same problem as yours it sounds.. so it probly wont do you any good but If you want to try my old one with new scrs you can have it

[weldonwelding]

Mine had close to the same problem, it would idle up when u strike an arc and you had to manually idle it back down with the switch, it never blew any fuses so maybe new scrs in my old board would work for you.

[k3500crane]

That is exactly why I joined this forum. People with a love for fabricating and the mighty blue boxes. That just may be the ticket for my dilemma. If my board has other faults, I can possibly take my good scr's and implant them into your good donor board. Sounds like a great idea. Thank you

[weldonwelding]

What's your address. I have the original anti static packaging to send it in as well. You can email it to me @ e.6strings@gmail.com

[weldonwelding]

Does yours look like this?

[k3500crane]

That is exactly the way mine looks. I have seen the new ones weldmart sells but what fun is that, I'd rather fix one.

[duaneb55]

Did you check for a shorted zanier diode D55?

[k3500crane]

I will check that diode and see. Not good enough at electronics to be able to diagnose faulty parts at a glance, I can check parts and replace if I know where to look. Be great if I can make 2 good boards out of these.

[k3500crane]

Ok, I checked the Zener diode d55 with my multimeter on diode check. Got readings of .723v one direction and 1.53v the opposite direction. No clue as to what those readings mean. Thanks for the help guys

[duaneb55]

Not being there, it doesn't sound good.

Check this out - http://www.ehow.com/how_5724083_check-zener-diode.html

The example is just that and doesn't reflect actual D55 values.

[weldonwelding]

Sent the board today, you should get it in the next couple days. The way it sounds... you will be much better off if you used the board i sent you just the way it is. But i would still put the new scrs in it so it will idle down on its own. Also since their only a couple dollars a piece i would get brand new scrs to put in it, theres a chance that the ones in the board you have could have been fried since you put em in.

[k3500crane]

I agree, they were cheap enough I will orders few more, may try to replace the Zener diode in my fried board just for kicks. I do appreciate everything. I will keep you posted on the progress. I love the old aead, it is mounted on my service truck and has been a great unit so far.

[k3500crane]

Update for anyone interested. Replaced the Zener diode #55 and still the same result. Still blows the inline fuse I put in. I am a pretty good parts changed but not such a good troubleshooter on electronics.
does anyone have the schematic for which terminal plugs onto which spot on the idle board? I have the manual but it doesn't show that.

[cody]

Problem with my 25 year old aeah 200le

Do you think if I change my circuit board it will solve my problem of high idel when I switch to weld but no arc. Only way I can low idel is to switch to power, I do have 120 volts, but no current when I switch to weld and the high idel problem. Thank you, Cody