Circuitry Problem! - Hardware & Software

Hey guys, I recently bought a nixie clock kit which consisted of two PCB's, all of the transistors, capacitors, micro-controllers and other components needed, as well as the tubes. I've soldered everything up and the connections look good, but for some reason when I plug it in, I get a high-pitched tone coming from somewhere on the board, and the tubes won't light up. Do any of you have any idea what this might be? My incoming voltage to the system is 9 volts, but coming out it's only about 126 mW, so something has a short circuit, but I'm not sure what. Maybe a transistor? How should I go about finding it and replacing it? Below are pictures of the PCB in mention, I already know that the PCB with the tubes is fine. [QUOTE][IMG]http://filesmelt.com/dl/2012-06-19_12-32-01_286.jpg[/IMG] [IMG]http://filesmelt.com/dl/2012-06-19_12-32-17_917_1.jpg[/IMG][/QUOTE]

The high pitch noise you are hearing is the high voltage switchmode supply, which is used to generate the high voltage required by the tubes. Looking at the bottom of the board I see a unsoldered pin on the bottom of the left side and make sure you've installed all the ICs the correct way around. You might also want to provide a link to where you've got the kit from and for any further problems you might want to try this thread: [url]http://facepunch.com/showthread.php?t=1160372[/url]. Edit: Also try checking if all transistors are the correct type, mixing up NPN and PNP can be a bad thing.

[IMG]http://www10.pic-upload.de/19.06.12/yv3ccnqd3vs4.jpg[/IMG] also looks like you forgot to solder some connections

[QUOTE=Lynrax;36401884][IMG]http://www10.pic-upload.de/19.06.12/yv3ccnqd3vs4.jpg[/IMG] also looks like you forgot to solder some connections[/QUOTE] Well I soldered them from the other side, should I fill those in a little better? [editline]19th June 2012[/editline] [QUOTE=ddrl46;36401651]The high pitch noise you are hearing is the high voltage switchmode supply, which is used to generate the high voltage required by the tubes. Looking at the bottom of the board I see a unsoldered pin on the bottom of the left side and make sure you've installed all the ICs the correct way around. You might also want to provide a link to where you've got the kit from and for any further problems you might want to try this thread: [url]http://facepunch.com/showthread.php?t=1160372[/url]. Edit: Also try checking if all transistors are the correct type, mixing up NPN and PNP can be a bad thing.[/QUOTE] The unsoldered pin in the bottom left corner is actually for screws to mount in wood, but I will look over all my solders again as well as check all the transistors and the ICs. I also posted this in the thread you suggested.

So I think I have it down to a transistor. If it's superheating, does that mean that I have it switched backwards, or it's a messed up transistor?

[IMG]http://i49.tinypic.com/4fztvo.jpg[/IMG] I think you might have soldered this MOSFET/VREG/transistor backwards.

[QUOTE=B!N4RY;36405151][IMG]http://i49.tinypic.com/4fztvo.jpg[/IMG] I think you might have soldered this MOSFET/VREG/transistor backwards.[/QUOTE] I think so too, I just needed some confirmation from you guys that that might be an issue. Thanks! I'll test it now. [editline]20th June 2012[/editline] So I flipped the transistor to the way it should, and I'm now getting 9.1V across the boards. It's still not lighting up though, so something is wrong. The transistors aren't heating up to burning temps anymore so that's a good sign. Is it possible that it could be one of the micro-controllers? I accidentally broke a pin off and replaced the pin, but I don't know..

transistors break pretty easly. maybe a few of them dont work anymore

[QUOTE=ewitwins;36406163]So I flipped the transistor to the way it should, and I'm now getting 9.1V across the boards. It's still not lighting up though, so something is wrong. The transistors aren't heating up to burning temps anymore so that's a good sign. Is it possible that it could be one of the micro-controllers? I accidentally broke a pin off and replaced the pin, but I don't know..[/QUOTE] You need to replace the transistors that were heating up first. They are most likely burnt out.

[QUOTE=B!N4RY;36408218]You need to replace the transistors that were heating up first. They are most likely burnt out.[/QUOTE] Alright thanks, in that case I'll probably end up replacing them both, just in case. Would this case the capacitors to not charge up to their full potential? They should both be up to 250V and they're sitting at 5.4, which is what I'm getting on the capacitors.

That's not how capacitors work. The 250v marking indicates the maximum voltage it can take.

[QUOTE=Lynrax;36408141]transistors break pretty easly. maybe a few of them dont work anymore[/QUOTE] It isn't 1957 anymore, transistors are quite robust unless you go rubbing them against the carpet like a mad man.