Question about the downboy

[bwcaw]

My dad bought the parts for a prt head from the sandwich shoppe with a downboy 700 driver board. I assembled the board into the ecan just like the instructions on the shoppe say, and the board tested out great. I potted it and put hooked it up to the lux III that we were going to use, and still fine. Finally I hooked it up and put it into the prt head, and for some reason it wouldn't work in there. I then took it out and checked all my connections (which entailed removing the potting /ubbthreads/images/graemlins/icon8.gif) and they were all fine. I then tested the board with the potting out of the ecan and it lit the led very dimly. Why won't it light full brightness? It is very frustrating to spend almost 3 hours assembling a light only to have the board stop working when you are almost done! What is the problem here? And is there any fix?

BTW I did test the led on my bench power supply and it functions properly, it is just the board that bad.

Thanks for any info you can provide! /ubbthreads/images/graemlins/grin.gif

 

[Shanghaied]

You are not alone on this one, I've also had a DB700 that works properly before assembly, but later could only drive a emitter very dimly.... can't offer any explanation, although before this post I thought I've done some thing wrong during the assembly (it was a Mclux head).

btw how did you manage to remove the potting? Did you use AA for the potting?

 

[bwcaw]

I used "two ton" epoxy. Not the recomended stuff, but I am glad I did now as I think AA would have been harder to remove. I gently heated it till it was warm to the touch and that softened the epoxy enough that I could pull it away in chunks with a fine tip forcep.

 

[bwcaw]

I just talked to Wayne, he is going to replace my downboy with a new one. What a guy! /ubbthreads/images/graemlins/thumbsup.gif

 

[PieThatCorner]

I'm in the dark about what happened... did the circuit board get fried? Was there a ground connected to the Ecan? What would have caused this? I'm about to try my unskilled hands at a similar project and would like to know as much as possible.

Thanks...

-Jim

 

[dat2zip]

The Downboy is pretty robust. One of the few things that can kill the downboy is accidentally touching the LED - Side to battery plus with the circuit running. While this sounds impossible, short wires on a bench make this more possible that it sounds. This will blow the IC internal switch.

There are probably many more things that can go wrong. Besides the Downboy stability issue which was the vendors fault by trimming the boards too much, the converter boards failure rate is very low.

There are a few boards out there that have a problem I have yet to resolve.

 

[PieThatCorner]

Thanks, Wayne... I'm learning as I go. /ubbthreads/images/graemlins/smile.gif

 

[bwcaw]

I think Wayne is correct, I am pretty sure I did short something out. It is amazing though, even with the downboy fried it will still put out some light. Thanks again to wayne for replacing the downboy! /ubbthreads/images/graemlins/thumbsup.gif So, just be carefull not to touch any of the wires together, also try to make your solder connections pretty small on the board, "the bigger the blob the better the job" doesn't apply here! /ubbthreads/images/graemlins/grin.gif

I just got a bare PR-T of my own (I assembled my dad's as a DD off of a pila) and I am considering forging into downboy territory again. PR-Ts are awesome.