Non bean build - MEK electronics BOR clone

[bmcash]

Hi everyone.  You may have seen my earlier post regarding how to properly debug a board using an audio probe.  Well, I have been trying to debug a BOR clone from MEK.  I have a few builds under my belt, including a few of the more simple madbean builds.  the BOR is slightly more complex that anything I have built and it shows because it is not working.  Here is the problem:

1)  guitar sound when by-passed - no sound when pedal engaged - no LED light either
2) 9V is reaching the board
3) after probing I do not get a signal after the first 2N7000 MOSFET - no voltages either
4)  I get a signal with the audio probe on the above MOSFET on the middle pin (ground, i think) only
5) triple checked components with DMM and reflowed solder, cleaned tracks with small exacto to remove potential solder bridges
6)  Will triple check the wiring.

The manual can be found here along with the schematic:

http://uk-electronic.de/onlineshop/product_info.php?cPath=105_192&products_id=1768&osCsid=578fbc3b0b8517cb99293e07a1f12005

I think I may have a short to the ground somewheres, but I am such a noob at this.  Any thoughts from you guys are well appreciated.  Thanks in advance.

B$ (BTW my last name is Cash, thats is the reason for the $ symbol)

[jkokura]

Cash,

So if you're not getting proper voltages or signal at Q1, then it's likely you've got one of the following problems:

- poor soldering on the board leading to a short to ground
- poor soldering on the board leading to a non-working/connected part
- a backwards or incorrect part
- poor or incorrect wiring.

Posting some high quality pics of both sides of you board, and working the debugging steps are really the only things I can recommend. I can tell you that it's very likely easily fixed. You will be able to get this working, but it will take some searching to find the issue.

Jacob

[bmcash]

Thanks Jacob.  I am going to rewire in the next few days; I need to take a 48 hour break from the pedal before I do more harm than good.  I feel you may be correct since my wiring technique definitely needs some practice.  I just wanted to make sure that I was heading in the right direction; I don't really understand the function of MOSFETs. 

Thanks again!

[bmcash]

Finally figured it out.  There were a couple of problems.  I mistaked a 82 resistor for an 82K resistor and re-wired the entire pedal.  Now it is working and I am loving the pedal. 

I also bought a new soldering iron that have a smaller/finer tip and this helps tremendously!  Thanks for helping and looking.

B$

[jimilee]

Excellent! You gotta watch out for 10k and 100k too,those guys are tricky!

[bmcash]

Lesson learned.  That's for sure.

[DutchMF]

To appropriate (and slightly alter) an old carpenters saying: "measure twice, solder once!" 

Paul