Results 1 to 8 of 8
  1. #1
    Join Date
    Jul 2004
    Location
    Poughkeepsie, Ny
    Posts
    631
    Had a no cooling call Friday at 8 PM. Intermittently shutting down the Air Handler. A/H is a Trane. We don't see many of these units out here. Why? I don't know. Usually we run into P.O.S. contractor or hack specials.
    Anyway. This unit is 15 years old. I poke around and find this little spark coming from this PCB.



    Curious, so I pull it and I find this.



    If you look to the left of the picture, you'll see where the PNP Transistor is mounted to the PCB.

    I'll be damned. That little transistor has a cracked solder joint. So, then I found a really good use for Stay-Brite. Field fixed that puppy and it was up and running in 10 minutes.

    Now, does anyone know where to get this PCB's? What is their purpose? The condenser was running when I got there and the coil was starting to ice up. Who carries them, or can you just get rid of them or what can you use to replace them? It connects to the Fan Center relay and then has two other wires to connect to them. And oh yes, it's a heat pump too.
    Happiness is the only good. The time to be happy is now. The place to be happy is here. The way to be happy is to make others so.
    -Robert Green Ingersoll

  2. #2
    Join Date
    Oct 2003
    Location
    Florida's space coast
    Posts
    2,538
    That CB controls blower on-off delay.

    Its available from any Trane/AS supplier.
    We've been doing so much,for so long,with so little, that now we can do almost anything, with nothing at all.

  3. #3
    Join Date
    Aug 2001
    Posts
    1,936
    the question is why did it crack a replacement will probably crack also in due time, is it because the board was not mounted on isolation mounts

  4. #4
    Join Date
    Aug 2002
    Location
    manitowoc wisconsin
    Posts
    4,943
    Originally posted by Edmund Forsthe
    the question is why did it crack a replacement will probably crack also in due time, is it because the board was not mounted on isolation mounts
    That is the most common pcb failure there is.I saw first hand when I used to hang out at my buddies tv shop years ago.I would say %90 of the repairs he made were on poor solder connections.It seemed worse on boards made in mexico.....Inferior solder?You tell me.
    Take your time & do it right!

  5. #5
    Join Date
    Jul 2004
    Location
    Poughkeepsie, Ny
    Posts
    631
    Originally posted by Edmund Forsthe
    the question is why did it crack a replacement will probably crack also in due time, is it because the board was not mounted on isolation mounts
    The fan center relay is mounted to the panel box case and the PCB is connected to the fan center, kinda just hangs there. It's weird that only one solder joint cracked and not the joints holding the PCB to the fan center.
    Happiness is the only good. The time to be happy is now. The place to be happy is here. The way to be happy is to make others so.
    -Robert Green Ingersoll

  6. #6
    Join Date
    Apr 2005
    Location
    NE PA
    Posts
    698
    Not so unusual. The crack appears to be at the location of one of the spade lugs. Mecganical stress from the attached wire plus some vibration and heat make a perfect combination for a fatigue crack like that. Board is otherwise most likely perfectly OKay.

    paul

  7. #7
    Join Date
    Dec 2002
    Location
    SouthEast NC ICW & Piedmont Foothills
    Posts
    7,635
    Isolate the Hot
    forget the board it`s 15 yr old
    plug fan & com to the 911 relay
    let everything else be

    that machine won`t know the difference

    I give the HO the option.
    It`s better to be silent and thought the fool; than speak and remove all doubt.

  8. #8
    Join Date
    Jun 2003
    Location
    Hell Hole Swamp
    Posts
    4,180
    Originally posted by dandyme
    Isolate the Hot
    forget the board it`s 15 yr old
    plug fan & com to the 911 relay
    let everything else be

    that machine won`t know the difference

    I give the HO the option.
    Ditto, those boards have a very high failure rate, usual failure is the fan wont turn off or a clicking noise

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