Need some help with capacitors.

[AirZoom]

Been having problems with my car, figured it was my ecu so i took it out.
I read the http://tmo.com/howto/ecu1g/caps.htm page, and my ecu is messed up in a different place. Check it out

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That little thing circled in red is burnt, and it fell of. What kinda capacitor is that? Where can I find the rating for it or a replacement.
Thanks guys.

 

[92awddsm]

I would suggest talking to steve or check his web page for repair.
http://simon.chi.il.us/~steve/Auto/DSM/ECURepair.html

 

[steve]

That little thing circled in red is burnt, and it fell of. What kinda capacitor is that? Where can I find the rating for it or a replacement.
Thanks guys.

I'm sure that's not the only problem. The part in question is a 0.1uF 50V SMD capacitor to filter high frequency noise from the +5v power.

Steve

 

[AirZoom]

Thanks for the info steve.
Too be honest, the ECU looks pretty good otherwise. The 3 other large CAPS do not appear to be leaking at all. The circut board looks pretty good, the only burnt liquid is around the area of that small CAP. Any idea what causes that one to fry?

Would it be better for me to buy a used ecu off ebay or send it in to get serviced by you.

 

[steve]

The SMD caps don't usually fail by themselves unless you exceed their voltage rating.
What doesn happen is electrolyte leaks out of the electrolytic caps, corrodes the solder and copper and shorts them out.

If you can't find somebody qualified to repair the ECU or a inexpensive replacement locally you can send it in.

Steve

 

[Eliteracingghmi]

Any surface mount component is a pain to solder and if you don't use a low-temp solder on it, you can damage the component before the solder even melts. Anyone with basic electronics knowledge can handle soldering a radial electrolytic capacitor (the large ones), but I don't even like to mess with surface mount components and I have my Associates in Electonic Repair. In short, send it in. It's better to have it done right and pay a lil more.

 

[AirZoom]

Hey. Thanks for the help Steve & Eliteracingghmi.

I guess I neglected to mention my dad is a electrician and he loves doing this kinda stuff. He mods satalites and built his own satalite programmers so this fell right into his line of work.

Anyways I went to a local Electronics store and managed to pickup the 3 Capacitors, as well as a replacement 0.1uF 50V cap. Steve you were right, 1 of my caps had leaked, and the acid did go on that 0.1uf cap and caused it to come loose. Instead of buying a surface mount replacement I got one with prongs, and my dad soudered it all up.

Hooked up the ecu, started clicking a bit at first and the check engine light was on, but the car did not die down like it had been, and after 5 seconds of idleing it stopped clicking, the check engine light went off and its now running great.

Thanks for the help guys.


Only downside is, I still spent $20 on those 4 caps cuz I had to buy each cap in a bag of 10-25.

 

[steve]

Hey. Thanks for the help Steve & Eliteracingghmi.

I guess I neglected to mention my dad is a electrician and he loves doing this kinda stuff. He mods satalites and built his own satalite programmers so this fell right into his line of work.

You can't get more local than that

Steve

 

[AirZoom]

Dammit! I spoke to soon
What the heck. Yeseterday the car ran absolutely perfect. Then today I go to start it up and its doing the exact same thing. Check engine light comes on, the car wants to stall out, ecu clicking and then it eventually dies.


Any ideas Steve? ECU Done for ?

 

[92awddsm]

Dammit! I spoke to soon
What the heck. Yeseterday the car ran absolutely perfect. Then today I go to start it up and its doing the exact same thing. Check engine light comes on, the car wants to stall out, ecu clicking and then it eventually dies.


Any ideas Steve? ECU Done for ?

Sonds like some of the copper traces might have been destoyed by the electrolyte that leaked on the board. Have you dad check continuity on the traces and Im sure you will probably find the problem.

 

[Eliteracingghmi]

It sounds like it's one of your tracks. The bad news though, is that it sounds like it shorted (the clicking is the give away). You'll have to check those tracks thoroughly with a multimeter.