Miller Electric

Welding Discussion Forums

Home » Resources » Communities » Welding Discussion Forums
 
Miller Welding Discussion Forums - Powered by vBulletin

Results 1 to 4 of 4
  1. #1
    Join Date
    Apr 2009
    Posts
    19

    Default Fried Dynasty 200

    My fan took a crap in my dynasty 200 and the tech said it took out the "Q" board. Does anyone know the part # of that circuit board? I looked through the manual and didn't see any boards labeled "Q".

  2. #2
    Join Date
    Aug 2008
    Location
    Orange, TX
    Posts
    1,215

    Default

    Seeing as the cooling fan is controlled by inverter control board PC1, I'd say that's the one in question.

    I suspect the tech's reference to "Q" board is a take on the fact control transistors are typically named Q1, Q2, Q3, etc. of which there are a bunch (51 I think) on PC1.

    A good electronics shop MAY be able to repair it given enough information however, some of these boards are multi-tiered and have traces on the front, back and sandwiched between a two piece laminated board making it difficult if not impossible to make a successful repair.
    Last edited by duaneb55; 10-26-2013 at 09:14 PM.
    MM200 w/spot controller and Spoolmatic 1
    Syncrowave 180 SD
    Bobcat 225G Plus LPG/NG w/14-pin*
    *Homemade Suitcase Wire Feeder
    *HF-251D-1
    *WC-1S & Spoolmatic 1
    PakMaster 100XL
    Marquette "Star Jet" 21-110

  3. #3
    Join Date
    Aug 2007
    Location
    Northern California
    Posts
    197

    Default

    Quote Originally Posted by duaneb55 View Post
    Seeing as the cooling fan is controlled by inverter control board PC1, I'd say that's the one in question.

    I suspect the tech's reference to "Q" board is a take on the fact control transistors are typically named Q1, Q2, Q3, etc. of which there are a bunch (51 I think) on PC1.

    A good electronics shop MAY be able to repair it given enough information however, some of these boards are multi-tiered and have traces on the front, back and sandwiched between a two piece laminated board making it difficult if not impossible to make a successful repair.
    That brings back memories of my time wasted working for Litton Industries as a technical writer. Litton is no longer in business but if I recall correctly, they were one of the first electronic companies to use the multi-layer circuit boards such as you mention here.

    They had some advantages in that they carried more components that a single layered board. On the negative side, they were nearly impossible to repair. Often, the technicians and engineers had to resort to digging holes in the boards to install haywires on the back side of the board. I always thought that it was comical to see a finished repair with wires running at odd angles on the board.

    You mention that Miller uses 51 separate discrete transistors on one of their Dynasty boards. That's really odd in the age of integrated circuits. I would think that they could do some redesign there, considering the prices that they are getting.

    For the record, I'd love to have a new Dynasty but considering that I'm still in hobby mode, it's not in the cards.
    Miller Syncrowave 200
    Milermatic 252
    Lincoln AC/DC "Tombstone"

  4. #4
    Join Date
    Sep 2009
    Location
    Colorado
    Posts
    216

    Default

    I was in the electronics business for many years, and I will make a few comments about board repair.

    If possible, the best solution is to cut all the leads to the part, and then unsolder the leads one at a time with a temperature controlled iron. If you do this right you should not damage the board. This is probably the safest solution for a less experienced operator, and does not require any special tools other than a good soldering iron

    In the production shop, they used a heat gun with a small nozzle to heat the board and part while the operator used a tweezer, nudging or pulling the part until it was free, and then removing the part. They kept the heat gun constantly moving to avoid burning something. These were not ordinary heat guns, I have never seen that type of gun available for sale in any store.

    The link below shows in general how to use a heat gun for that purpose, but the heat gun he uses has a large nozzle.

    http://www.instructables.com/id/Heatgun-Desoldering

    One could use solder wick to remove the excess solder from the pads or holes.

    But one would probably want to practice this technique before using it on a $500 circuit board. ;-) Or better, take it to somebody who does this every day.

    Richard



    Quote Originally Posted by duaneb55 View Post

    A good electronics shop MAY be able to repair it given enough information however, some of these boards are multi-tiered and have traces on the front, back and sandwiched between a two piece laminated board making it difficult if not impossible to make a successful repair.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Warning: Function split() is deprecated in /mnt/stor3-wc1-dfw1/357822/357839/www.millerwelds.com/web/content/lib/footer.inc.php on line 82

Welding Projects

Special Offers: See the latest Miller deals and promotions.