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New Millett Hybrid MiniMAX (what happened to this thread?) - Page 117

post #1741 of 1944
Quote:
Originally Posted by jdkJake View Post




I thought Tom's advice was excellent (see above).

 

EDIT: Oops! just saw you did that. Before or after you resoldered?


I tested all the solder joints before and after I desoldered and resoldered. I have been at this since 4:30, it is now 10. I don't think I missed any solder joints.


Edited by BobSaysHi - 9/7/10 at 8:05pm
post #1742 of 1944

Okay. Well, probably best to take a break and pick it up tomorrow.

 

You still have a short somewhere on the board. Just have to find it. I will take a look at your pictures again once I get back to my big screen.

post #1743 of 1944
Quote:
Originally Posted by jdkJake View Post

Okay. Well, probably best to take a break and pick it up tomorrow.

 

You still have a short somewhere on the board. Just have to find it. I will take a look at your pictures again once I get back to my big screen.


OK, I'll keep trying tomorrow. My board looks much cleaner now, If I was you I wouldn't bother looking over it again. If I don't find anything tomorrow I will post newer pictures.

post #1744 of 1944
Quote:
Originally Posted by BobSaysHi View Post




OK, I'll keep trying tomorrow. My board looks much cleaner now, If I was you I wouldn't bother looking over it again. If I don't find anything tomorrow I will post newer pictures.





Okay. Standing by for new pics.

You might want to scan the top components and be sure you do not have any leads touching. Perhaps a resistor touching a cap shell or heatsink or a cap shoved up against a heatsink. Also look at the pins of your transistors and be sure they are not shorting because of a solder blob.
post #1745 of 1944

I cant find a short. I've spent longer looking for a short than I did building the thing.

 

Is it possible that I broke a part? Or perhaps put a cap in backwards? Or put anything in backwards? Does dog hair conduct electricity? If the trimmers are all the way down is it possible the amp could not turn on at all? Do the DIY gods hate me?

 

Remember, the amp turns on for less than a second and then the leds dim and turn off. If you are still convinced there is a short I'm just going to put it on a shelf and leave it there.

post #1746 of 1944
Nah man, that's half the fun of DIY. Figuring out where you screwed up. ;-)



It's cool, it happens to everyone. If you must, step aside a day or two, but rest assured, we will figure it out.



So, have you verified the orientation of all your polarized parts? How about all of your transistors? Can you measure the voltage across the polyfuse and let us know what it measures at?



Most of all, where are the pictures you promised? You SAID there would be pictures! ;-)
Edited by jdkJake - 9/8/10 at 6:40pm
post #1747 of 1944

It rained 7 inches overnight and my house flooded, I'll have a camera either tomorrow or friday. I have no more time to invest this week. It looks like I have to replace all the carpet in my house. If I sound frustrated about my amp its because of other things. 

 

edit: It actually rained 8+ inches 


Edited by BobSaysHi - 9/8/10 at 9:10pm
post #1748 of 1944
Ouch. Sorry to hear that.

Worry about your house and family first. Everything else is secondary.

We will be here when you are ready.
post #1749 of 1944
Quote:
Originally Posted by jdkJake View Post

Ouch. Sorry to hear that.

Worry about your house and family first. Everything else is secondary.

We will be here when you are ready.


You guys on head-fi are the nicest people I've had the pleasure of talking to on the internet. Thank you and TomB for your patience. 

 

I'll try and take pictures on friday, however if I get up to radioshack tomorrow, I will have pictures then.

post #1750 of 1944
Quote:
Originally Posted by BobSaysHi View Post

I cant find a short. I've spent longer looking for a short than I did building the thing.

 

Is it possible that I broke a part? Or perhaps put a cap in backwards? Or put anything in backwards? Does dog hair conduct electricity? If the trimmers are all the way down is it possible the amp could not turn on at all? Do the DIY gods hate me?

 

Remember, the amp turns on for less than a second and then the leds dim and turn off. If you are still convinced there is a short I'm just going to put it on a shelf and leave it there.


There is always the possibility that you turned the trimmers the wrong way, and it's reacting to too much current pushed through the buffer.

 

In any event, I agree with Jake - it sounds like you have more important issues to resolve right now.  I hope the damage wasn't too bad, considering - good luck!
 

post #1751 of 1944
Quote:
Originally Posted by tomb View Post




There is always the possibility that you turned the trimmers the wrong way, and it's reacting to too much current pushed through the buffer.

 

In any event, I agree with Jake - it sounds like you have more important issues to resolve right now.  I hope the damage wasn't too bad, considering - good luck!
 


The damage wasn't very bad, and my family finally has an excuse to get new carpet.

 

The site said to turn the trimmers clockwise till they clicked and I made sure to do that. However, I might not have turned them down the very first time i turned it on (it's been a couple long weeks and i don't remember). Is there any way to check if they are damaged? 


Edited by BobSaysHi - 9/9/10 at 3:30pm
post #1752 of 1944
Quote:
Originally Posted by BobSaysHi View Post




The damage wasn't very bad, and my family finally has an excuse to get new carpet.

 

The site said to turn the trimmers clockwise till they clicked and I made sure to do that. However, I might not have turned them down the very first time i turned it on (it's been a couple long weeks and i don't remember). Is there any way to check if they are damaged? 


Yes - using the ohms feature of your DMM.  Pick one pin of the two that are on the same trace for one probe of the DMM - then place the other probe on the single pin that's not on a trace.  You should be able to measure changes in resistance, depending on how you turn the screw.  All the way clockwise should be 2K on the buffer trimmers, for instance, while all the way counter-clockwise should be 0 ohms.  As long as you can measure changes in resistance from moving the trimmer a couple of turns, then they're OK.  There's no need to turn 25 turns just to see if they'll go to zero, iow.
 

post #1753 of 1944

Well I did a search of the forum and could not find what I was looking for, so be kind if it is already out there.

 

I am in the middle of soldering up my board and have come to the tube holders.  Now my PCB has a bow to it and I am looking for advice on whether to solder them flush with the board or to solder them so they are even and flat.  I am concerned if I take the even and flat route the tubes will be catywampus if the PCB gets straightened  during the install in the case.

 

Thanks in Advance!

post #1754 of 1944
Quote:
Originally Posted by FishHead View Post

Well I did a search of the forum and could not find what I was looking for, so be kind if it is already out there.

 

I am in the middle of soldering up my board and have come to the tube holders.  Now my PCB has a bow to it and I am looking for advice on whether to solder them flush with the board or to solder them so they are even and flat.  I am concerned if I take the even and flat route the tubes will be catywampus if the PCB gets straightened  during the install in the case.

 

Thanks in Advance!


The bow is minor and as you say, the case mounting will take it out.  IMHO, you should bend the tube socket pins out far enough that they just fail to fit into the holes in the PCB.  That way, the sockets have a force fit into the PCB.  You may even find that with some judicious pin-bending, you can actually adjust the fit so that they're completely flush at the start.

 

Put both sockets in this way, then flip the PCB over onto a board.  Press down firmly on the PCB while soldering each pin.  Do this by applying plenty of solder - the holes should be completely filled and the solder should wick up the pins on the top side of the PCB by 1/8 - 1/4".  (Remember that the tube socket joints are just as much mechanical as electrical, so they need a lot of the strength that comes from a well-soldered joint.)  While still holding the solder iron to the joint to keep the solder melted, release the solder in your free hand so that you apply force to the bottom of the PCB, forcing the socket flush to the PCB (it's upside down, remember).  Release the soldering iron while continuing to press down until the solder cools.  Do this alternating from one socket to the other, and from one pin on each socket to the opposite pin on each socket - like alternating lug nuts on a car tire/wheel - until you get all the pins soldered. 

 

You can lift up the PCB periodically, turn it over, and check for socket level after soldering a pin on each socket, in turn.  If the sockets look out-of-level, then press down slightly in the opposite direction of the out-of-level when you go to solder another pair of pins.  Probably the best description I have of soldering tube sockets into a PCB is in the Build Thread for the Starving Student or on the Starving Student website here:

http://www.diyforums.org/SSMH/SSMHconstruct3.php

 

The principles remain the same for any PCB tube socket and PCB.

 

 

P.S. Don't over-obsess about this.  It's nice to have them straight and flush, but you'll find that most tube bases are far from it.  The tube pins can be slightly bent to overcome any out-of-level tube socket.
 


Edited by tomb - 9/12/10 at 5:51am
post #1755 of 1944

Thanks for the link. That was what I was looking for.

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