Help with Oxygen Hacker Analyzer

[ron_cooper]

I have gotten everything done to make my own mixing stick and am down to making the analyzer in the Oxygen Hackers book. I had gotten two PM128A meters so I could make a second one after I made the first one. While making the one I removed the R3 resistor the way described in the book and completed all the other wiring. However when I installed the battery the display did not come on. I checked the wiring and it all seemed to be O.K. I thought I had done something wrong so I desided to try the second meter. Before starting anything I first put the battery wire leads into the circuit board and installed the battery to verify the display worked. I then repeated the same things I did to the original board, doudle checked the wiring and installed the battery. Again it did not come on. I have checked the solder pads on the R3 section to verify that the two pads are not shorted out, their fine. I am at a loss as to what might be the problem. I have sent a message to airspeed but am still waiting for a reply. Any help would be appreciated. I am guessing I may have to start with another two meters but hope that I don't end up with four meters that still don't work.

 

[captndale]

The printed circuit work assembling the El Cheapo is somewhat delicate. Double check everything you did and I'll bet you will find the problem.

I have been assembling electronic devices that require soldering work since I was about eight years old (Heathkits, etc.) and I find it difficult to work on modern circuit boards. The miniaturization has progressed to a point that it is exceedingly difficult to make a solder connection without causing an unwanted bridge, delaminating a path or unintentionally breaking a connection. The parts are so small and so close together that it is a good idea to work under a large bench mounted magnifier.

 

[mikeb663]

Did you make the rest of the connections before powering it up? I'm not sure if it would make a difference, and can't think of any reason it would. I just put together one of these analyzers from the Oxyhacker book, and had no issues, but I did not power it up until the rest of the connections were made. I would just check the wiring again and make sure that it is right. If you post a picture of your work thus far it might help me, or hopefully someone better with electronics, to troubleshoot the problem. Good luck!!

 

[ron_cooper]

I have been in touch with the folks at oxygen hacker and they have made a few good suggestions for me to check, as well as a different spot that can be used instead of the lower pad were the R3 resistor was removed. Everything checks out OK. I have triple checked the wiring so my only guess is I have messed up something internal in the process. I have ordered two more meters and will try again. The next time I will do all the checks before I install a battery. I won't be giving up on having the analyzer completed. I'll try to get a few good pictures of the one I still have wired up.