[Juaquin]

Well that was better (and more concise) than any of my physics professors have ever explained that.

 

[kuroguy]

Tomb,
that was an extremely accurate description of the physics behind radiant and convective cooling. I haven't heard it put so technically corect since my heat transfer class in college.

As an air conditioning engineer with an intimate knowledge of the processes involved I whole heartedly agree with your assessment of the situation.

As usual, thanks for the input.

 

[Nonchalance]

Alright, I finished mine, doesn't work. Nothing lights up or heats up, not even a whisp of smoke to tell me I ****ed up

What tests should I do to isolate the problem and fix this? Wiring can be seen on one of the previous pages.

I'll take pics in the morning when there's better lighting.

 

[Juaquin]

If the LEDs aren't lighting up, that's a major issue. From what I know it could be a few things. The LED resistor could be touching the mounting screw/nut assembly, causing a short. The LED leads could be shorting together in the sockets. There has to be a short somewhere (or the power supply is bad).

 

[Nonchalance]

Hi res pics hosted at Mediafire.

Thanks a lot. And yes, it's just as messy outside of the case.

Quote:

Originally Posted by Juaquin /img/forum/go_quote.gif If the LEDs aren't lighting up, that's a major issue. From what I know it could be a few things. The LED resistor could be touching the mounting screw/nut assembly, causing a short. The LED leads could be shorting together in the sockets. There has to be a short somewhere (or the power supply is bad).

I'm doing a ptp build, hehe. Not using an LED but the tubes aren't lighting up.

How do I test the power supply? I feel like I did all the wiring correctly, triple checked like everything when I did it.

 

[nullstring]

that sure is messy looking..
I was gonna try and help, but I'm having a hard time following the wires.

pmillet gave such a good example of how a clean build could be done. why don't people try and follow that more >_<

Because nothing is catching on fire, and you think you wired everything correctly, I would say that you probably have a cold solder joint somewhere.

easy things to do:
if you look at the schematic, there is a point that says "48V". measure the voltage there, and measure the voltage where it says "19V", which should be pin 3 of the tube sockets.

because neither sides are working.. I would look more toward the beginning of the circuit... around C1 and C6...
I specifically can't really "read" your wires for that.

checking voltages on pin 2 of your FETS might not be a bad idea either.

Honestly, I have hardly any idea what I am doing, so take my advice with a grain of salt.
You might want to check your connections to ground too... I soldered my terminal strips..

 

[Nonchalance]

Yea trying this in a small case was a bad idea. I don't have a multimeter at the moment, so can't test anything, I'll grab one soon.

Meanwhile.

MOSFETs read 1,2,3 when with the pin side down and metal side down right?

My wiring for power section:

 

[nullstring]

your diagram is good.

lol, a multimeter would help =p

and, yeah, thats how the mosfet pins are.

EDIT: thats making the relatively safe assumption that the second "C1" is really a "C2"
EDIT2: put a more relavent (and correct) picture up, didn't realize that mosfets wouldn't all have the same pinout.

 

[Nonchalance]

Yea oops, that should say C2. My bad.

Going to resolder some points just for right now.

 

[nullstring]

good luck

 

[tomb]

Umm ... thanks for the help, nullstring. Thank goodness you felt like diving into that.

Just an FYI, but the IRF510 MOSFETs go like this:
1. Gate
2. Drain
3. Source

 

[Nonchalance]

Sorry for my fail organization skills guys, I'll report back with measurements on MOSFET pin, tube pin, and the 48v place.

Thanks for all the help.

 

[tomb]

Quote:

Originally Posted by Nonchalance /img/forum/go_quote.gif Sorry for my fail organization skills guys, I'll report back with measurements on MOSFET pin, tube pin, and the 48v place. Thanks for all the help.

Good luck!

One thing you might look into - the Cisco power supply has an excellent over-current protection shut-off. If it connects into a dead short, it'll just act like the power supply is dead. No noise, no delay, nothing - it will just fail to produce any voltage. So, if your power-up situation is acting like that ... then look for a short somewhere.

 

[ethan961]

So all was well with my SSMH until recently when I tripped over a cord and the amp went crashing to the ground. It appears nothing was damaged (tubes are both fine) however one of the tubes is now getting 48 volts for some unknown reason. I've checked all the wiring, and I can't for the life of me figure out what happened. Nothing is shorting, all the joints look good... one tube does get 19 volts like it should and is functioning normally. The problem does not follow the tube. I'm sure someone knows off the top of their head where exactly I would need to check, because I am rather lost. I'll admit I am having a hard time following my own wiring, but hey, it was my first electronics build period. (this is PTP btw)
Anyways, if anyone knows what might be going on, a little help would be greatly appreciated.
Thanks,
Ethan

 

[tomb]

Quote:

Originally Posted by ethan961 /img/forum/go_quote.gif So all was well with my SSMH until recently when I tripped over a cord and the amp went crashing to the ground. It appears nothing was damaged (tubes are both fine) however one of the tubes is now getting 48 volts for some unknown reason. I've checked all the wiring, and I can't for the life of me figure out what happened. Nothing is shorting, all the joints look good... one tube does get 19 volts like it should and is functioning normally. The problem does not follow the tube. I'm sure someone knows off the top of their head where exactly I would need to check, because I am rather lost. I'll admit I am having a hard time following my own wiring, but hey, it was my first electronics build period. (this is PTP btw) Anyways, if anyone knows what might be going on, a little help would be greatly appreciated. Thanks, Ethan

Actually, it's possible that one of the tubes developed a short. If the plate connections short with the heater connections somewhere inside the tube, then the heaters may see 48V. Just a guess ... but it might explain what you're seeing.