New build - No power


 
I did verify the BS170's last night. They are in the right place. I also gave the board another alcohol scrub. I'll be bridge hunting tonight, thanks.
 
Understood. I was able to read BS170 on the flat side of those components, where they should have been, and did not see that on the regulator when I peeked at it.
 
Post some high res pic's (in focus, after the cleaning) so we can help you trouble shoot.

Ralph, please don't shout, ouch my ears........;)
 
OK, if the regulator label was different from the BS170 then I guess that kinda verifies things (unless somehow you got an altogether wrong part).

So you are now looking for a solder bridge somewhere on a 5V lead. whatever it is shorting that out and making you measure 0 Ohms from 5V to ground.
 
Peter F said:
Post some high res pic's (in focus, after the cleaning) so we can help you trouble shoot.

Ralph, please don't shout, ouch my ears........;)
Click to expand...

Is there anything other than alcohol and a toothbrush I can use to clean my board? I have scrubbed on 2 occasions, and while it did take care of the residue on the board itself, the joints I soldered are still discolored a bit. Maybe I'm not scrubbing long/hard enough? I will take a series of close up hi res pics tonight and post.

Ralph has earned the right to shout at me in caps for as much help as he has provided. I'm using it as a barometer of my circuitry competence :)
 
RalphTrimble said:
OK, if the regulator label was different from the BS170 then I guess that kinda verifies things (unless somehow you got an altogether wrong part).

So you are now looking for a solder bridge somewhere on a 5V lead. whatever it is shorting that out and making you measure 0 Ohms from 5V to ground.
Click to expand...

Cool. Can't wait to dive in and find it. Thanks!
 
Dominick A said:
Is there anything other than alcohol and a toothbrush I can use to clean my board? I have scrubbed on 2 occasions, and while it did take care of the residue on the board itself, the joints I soldered are still discolored a bit. Maybe I'm not scrubbing long/hard enough? I will take a series of close up hi res pics tonight and post.
Click to expand...

The color of the solder joints depends on the quality of soldering. A good joint should be shiny, when the joint is dull it means that the temp was too high or too low or that the heating time was either too long or too short. You can brush a dull joint all you want but it will never shine.
 
They do make flux removal products/sprays for cleaning boards but you should be able to get it done with alcohol and a brush. I would be interested to see what your board looks like now after some cleaning, because the pics you posted had a lot of charred areas and it was hard to see what is really going on there. Perhaps cleaned up it would be easier to spot the solder bridge.

Here is a diagram that shows where various voltages are present on the board, pay particular attention to the RED +5V spots:

hm-424.png


My guess....

The LCD contrast pot (that blue box thing) has 5V on it, that part is soldered in on the other side of the board so the pins are completely surrounded by the ground plane there. The soldering looks sloppy so there's a good chance to short that 5V pin to ground right there. Clean up that solder joint by removing a bunch of that solder. Also, the LCD Backlight jumper has 5V on it, clean that up and verify it is isolated from the ground plane also. The diagram should give you a hint on where to look for the short. (ignore the 3 red circles, I guess they were left over from helping someone else)

As for cleaning things up... Do you have a solder sucker or a role of solder wick? You kinda need one or the other to do the cleanup work properly. The cheapest/easiest way to go would be solder wick...
 
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Peter F said:
The color of the solder joints depends on the quality of soldering. A good joint should be shiny, when the joint is dull it means that the temp was too high or too low or that the heating time was either too long or too short. You can brush a dull joint all you want but it will never shine.
Click to expand...

Ok. I was having issues with my tip not tinning and getting too hot. Is there any danger in having a dull joint, or is that just a cosmetic issue at this point?
 
Cold solder joints are a problem, yes, but not every dull joint makes a cold solder joint.

I'm pretty sure you've got the point by now, we are looking for a short circuit not an open circuit here. After you fix the short circuit you may have to deal with cold solder joints, maybe not. I would concentrate on the short for now....

If you have other issues after you clear up the short the best thing for you to do would be to use a solder sucker or solder wick to remove excess solder wherever present, then go through the board and very quickly apply a little fresh solder and reflow each joint.
 
RalphTrimble said:
They do make flux removal products/sprays for cleaning boards but you should be able to get it done with alcohol and a brush. I would be interested to see what your board looks like now after some cleaning, because the pics you posted had a lot of charred areas and it was hard to see what is really going on there. Perhaps cleaned up it would be easier to spot the solder bridge.

Here is a diagram that shows where various voltages are present on the board, pay particular attention to the RED +5V spots:

hm-424.png


My guess....

The LCD contrast pot (that blue box thing) has 5V on it, that part is soldered in on the other side of the board so the pins are completely surrounded by the ground plane there. The soldering looks sloppy so there's a good chance to short that 5V pin to ground right there. Clean up that solder joint by removing a bunch of that solder. Also, the LCD Backlight jumper has 5V on it, clean that up and verify it is isolated from the ground plane also. The diagram should give you a hint on where to look for the short. (ignore the 2 red circles, I guess they were left over from helping someone else)

As for cleaning things up... Do you have a solder sucker or a role of solder wick? You kinda need one or the other to do the cleanup work properly. The cheapest/easiest way to go would be solder wick...
Click to expand...

Yes, I have both a wick and a sucker.
 
OK, you're good to go then. I would use the sucker to suck away solder from the 3 legs of the contrast pot, then measure to see if your 5V short is still present.
 
Just agreed to do pulled pork for a work potluck on 10/20, that should be more than enough motivation to power through this :)
 
Ok, did some hunting, wicked out what I thought were joints too close for comfort and still no luck. Here are some new pics. I'm not sure what I can do at this point. Any ideas with some veteran eyes?

Front - https://drive.google.com/file/d/0BzSBmZGY0VqYZGV6WVhmWnNTMkE/view?usp=sharing
Front Right - https://drive.google.com/file/d/0BzSBmZGY0VqYeWhBajVfdDNkVnM/view?usp=sharing
Back Right Side - https://drive.google.com/file/d/0BzSBmZGY0VqYbzNKV2VDWkk0Vm8/view?usp=sharing
Front Center - https://drive.google.com/file/d/0BzSBmZGY0VqYTWVrWGtoa1JBNEE/view?usp=sharing
Front Right - https://drive.google.com/file/d/0BzSBmZGY0VqYN25nSE5UQVpYSUk/view?usp=sharing
Back Right - https://drive.google.com/file/d/0BzSBmZGY0VqYbUdKUGZHZElIUTg/view?usp=sharing
Back Left - https://drive.google.com/file/d/0BzSBmZGY0VqYYkVFbWotWXVVUm8/view?usp=sharing
 
yah, see the blob of solder on the leg of the +5v regulator? (the OKI device that is a little circuit board) You can see it in the BACK RIGHT SIDE photo. On the top side of the board, between the HM board and the OKI board. It looks like there might be enough solder there to short out those two legs? Those two legs are +5v and Ground....
 
I agree with Ralph, the OKI regulator would be the first thing to check.

Just a question, what kind of solder are you using? Almost none of the joints have properly flowed. I would remove most of the solder of all the joints and re-solder them with a good quality solder or use some additional flux.
 
Peter F said:
I agree with Ralph, the OKI regulator would be the first thing to check.

Just a question, what kind of solder are you using? Almost none of the joints have properly flowed. I would remove most of the solder of all the joints and re-solder them with a good quality solder or use some additional flux.
Click to expand...

Here's what I'm using to solder. I think the iron has been my biggest problem. I'm pretty sure it is running way too hot, especially after all of the feedback I've had in this thread and others.

Solder - http://www.amazon.com/exec/obidos/ASIN/B000G36BYU/tvwb-20
Iron - http://www.amazon.com/exec/obidos/ASIN/B0006NGZK0/tvwb-20

I won't be able to get back to fixing the OKI or anything else you might see until later this weekend. I really hope I don't have to start from scratch with this.

Thanks for the feedback!!!
 
Just as a tidbit, I used that exact same iron to do mine, and it was my first time ever soldering electrical components to a board. I've done wire to wire, and plumbing solder though.

Mine came out just fine and I've been using it for a few weeks now. So the iron will work, you just need to get the technique down I guess.
 
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