MT-2 Mod Problem

HNB · Post by **HNB** » Mon Jan 18, 2016 5:36 am

Hey pedal experts, I am trying to solve a problem with my pedal. I did one of those mod kits on eBay and everything works except the mid knobs. The tone pot stack works, volume works, and distortion. I checked and rechecked my capacitors and they all seem ok. I dont see any solder jumps or anything. Anyone familiar enough with schematics or this pedal to give me an fyi on what capacitors the mid knobs use so I can narrow it down? I emailed the supplier, but no idea if they will help me.

HNB · Post by **HNB** » Mon Jan 18, 2016 5:58 pm

BTW if you or someone you know is really good at fixing pedals and could fix whatever it was I messed up, I would gladly send it their way and give them some cash for their trouble. It is probably a simple fix, but I don't know schematics and stuff well enough to figure it out.

NickS · Post by **NickS** » Mon Jan 18, 2016 10:27 pm

High-res pics are useful, both sides of the board, and the details/schematics for the mod.

HNB · Post by **HNB** » Tue Jan 19, 2016 12:19 am

Here are some pics.

20160118_161451 by Christopher Louck, on Flickr

20160118_161351 by Christopher Louck, on Flickr

20160118_161423 by Christopher Louck, on Flickr

BossMT2 by Christopher Louck, on Flickr

NickS · Post by **NickS** » Tue Jan 19, 2016 9:47 am

You changed/removed all the caps circled in the instructions?

71Smallbox · Post by **71Smallbox** » Tue Jan 19, 2016 2:15 pm

That is a fuck-load of solder joints to attend to. Make sure that all of the ones you soldered aren't cold joints and that none of the traces or leads touch via solder drip where they're not supposed to. With that many points, it could take a while to determine the problem. I can't tell from the pics of the PCB are blurry. Make sure the caps are oriented correctly(the bipolar ones, the electrolytics) and that the diodes are too.

NickS · Post by **NickS** » Tue Jan 19, 2016 2:18 pm

Picture quality isn't good enough to assess whether there are any possible bridges.

The caps that are in the Mid loop are C37, C38, C43 and C36. C43 is on the daughter board with the pots and you didn't touch that. C38 wasn't swapped. So the only things you've changed in the Mid loop are C36 and C37. Double-check those.

HNB · Post by **HNB** » Tue Jan 19, 2016 3:31 pm

Will do. If those are ok, I will check the ribbon connections by doing a wire bridge in case there is a break in the ribbon cable.

I really appreciate the help looking at the schematic. There are a ton of parts on this thing. LOL At least the diagram I got has the capacitor numbers. LOL

NickS · Post by **NickS** » Tue Jan 19, 2016 5:14 pm

There are higher-res mt-2 schematics on the net than the one I pulled from your link, though your original may be good.

Fran · Post by **Fran** » Tue Jan 19, 2016 5:23 pm

HNB wrote:Here are some pics.

20160118_161451 by Christopher Louck, on Flickr

Christ. I can remember when I used to have the patience to do stuff like that

HNB · Post by **HNB** » Wed Jan 20, 2016 2:05 am

So I am at the point of throwing it away. I have wasted four days working on this thing. Unless someone is cool with me mailing it to them to screw with, I am done with it. I have another one coming in that I got for $35. Kind of bummed I can't figure it out. If anyone wants it, let me know. The distortion, tones, and volume work fine. Just the mid controls don't do anything.

HNB · Post by **HNB** » Wed Jan 20, 2016 3:32 am

One of my friends is dating an electronics graduate who said he will take a look at it. Fingers crossed. If he can tell me what is wrong, I can try to make sure I avoid it in the future. So frustrating having it not work when the fix could be very simple... It is just beyond my knowledge.