HELP

[jap813]

ok heres the deal I switched everything from good board to bad one and still nothing the 3.3 reg still gets hot to the touch on the bad board. Could it be a bad pcb?

[tbone321]

It there was no power coming out of the transformer, then the heatsink on the 3v regulator would not be getting hot.  It really looks like you have a short on the 3V side.  I would take a close look at the small caps to the right of the regulators and make sure that they are installed with the correct polarity and that there is no solder bridge shorting either one of them out.

[jap813]

yes been there done that as I said I switched all parts from good board to bad board and still the same thing the bad board does not work and the good one does still work

[tbone321]

If you are replacing ALL of the parts and theses parts are working on the other board then that indicates that the components are all ok and that there is a short on the "bad board".  I would check the bottom of the bad board for a solder bridge.  If you have already soldered in your sockets take a look at the one below the transformer.  I would also make sure that the board is clean. 

[jap813]

I am  an idiot I did not look close enough to notice that I had 2 5 volt regs.

[KeithTarpley]

Greetings,,,

Finding a problem is what we've all had to do.  So, everything is working now?

Keith

[jap813]

yes both units are working now

[RJ]

Great! it is good to see you got them working. Just for everyones info the PCBs I get all get electricaly tested (does not cost much extra) to try and keep from having issues were the pcb would be the issue. As of so far with thousands of the units out we have never found the PCB was the problem that I am aware of. Doesn't mean it could never happen but it is always hundreds if not thousands of time more likely that is is a simple build issue.

As if you every notice new builders are almost always good on the first unit and if they are going to have a problem it is the mean old second one that gets them. Anyone know why this is?   

RJ

[tbone321]

Yea, overconfidence.  The first one is usually immersed in paranoia.  Did I use the right component???  Is that part in correctly???  Did I solder that correctly???  Am I going to kill myself or the board???  The first board is built with great care due to these and other fears.  Since the board has a good layout and with the excellent instructions provided, for many the first build is successfull and turns out to be not all that hard afterall but a bit time consuming.  Now with this new confidence and the desire to shorten the build time , sometimes things are missed or done incorrectly.  In a way this is also a good thing as it gets the builder much more familiar with the device layout and operation while trying to debug it and shows that rushing tends to cost more time than it saves. 

[Kwajtony]

That would never happen to me.

 

[tbone321]

Of course it wouldn't, me either