OS-2 Mod fails

Started by chugachjed, May 13, 2017, 09:37:33 PM

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chugachjed

So I keep thinking I can do this electronics thing. Built a 5F1 and wired the output transformer backwards (had to have a tech figure out why it didn't make sound) now I've failed modding a Boss OS-2. I picked up Fromel Electronics mod kit and got ahead of myself and replaced all the capacitors in the kit without testing in between. Pretty sure I got the polarity right on the electrolytics but when I plug it in the LED doesn't light up and it makes a loud hum with increasing volume. Any ideas where I might have screwed up?

robthequiet

#1
OK, deep breath... something's open, something's shorted, possibly a bit of both. There is a troubleshooting basics thread you should probably read before anyone can help to figure it out:

http://www.diystompboxes.com/smfforum/index.php?topic=29816.msg202738#msg202738

Don't get overwhelmed, just take it step by step and ask questions any time.

Edit: Here is a good place to go as well, maybe even before the other link: http://www.diystompboxes.com/wiki/index.php?title=Debugging


chugachjed

That troubleshooting might be over my head at the moment. The loud hum was a ground problem. I desoldered the sloppy ones I had done, because I had no desoldering tools, and resoldered them. Now the led comes on and there is some signal getting through when I turn the level on the pedal the amp hisses and if I pull the cord from guitar to pedal out while the pedal is on the amp makes sound. With the pedal on or off though there is no guitar sound coming through. Going to pull it back apart and do the arduous process of checking every cap I changed.

robthequiet

Yeah, don't sweat the theory too much. Just need a taste of the concepts. 90% chance it's one or two questionable connections. Check for solder bridges, loose components, etc.

Do you have a meter to check voltages?

chugachjed

I do. Need to get the kids in bed before I take it. Ack apart.

bluebunny

You don't need to take anything apart.  Just follow the link Rob posted and fill in the values.  If you don't want to read it all (I would), then just skip to the checklist and start filling in.  Report back here and we'll get it sorted.

And welcome.  :)
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