vic7767 wrote:That's the reason for this thread. It is easier to solder three wires to the circuit board and then connect the TO-220 MOSFET that soldering a SMD into place. Also the MOSFETs can't take much heat. No more that 2 or 3 seconds per connection. Also a little solder flux paste makes the job a bit easier.
Not only "supposed..." but actually connected inside the FET's case, as well as by Cu PCB tracks. That large tab and the smaller middle (typically) lead, opposite side of case, connects to the power-FET's DRAIN electrode.Jeff Carver wrote:... But what I haven't seen in any of the pictures is the little copper strand going (I think) from the middle pin, under the chip, to the tab. Are that tab and the middle pin supposed to be electrically connected?
Your are quite welcome.Jeff Carver wrote:...Thanks for the clarifying photos, Gordon.
Not much heat is required to soften the adhesive that bonds copper foil to the PCB's substrate.... on the U4, I've pretty well destroyed the mounting points for several of the connections. I don't know if I used too much heat to desolder or what. ...
It might be salvageable. Here is another image to work from. Its view is shifted down to show more tracks, and some markings have been inserted: The first things to check, visually and with optical magnification, are some of the narrow tracks of copper to ensure they are still connected as needed....Is there any recovery from this, or do I need to replace the motherboard now?
newmom wrote: is there anyone on this board who does this repair with some confidence for a price,
Users browsing this forum: vic7767 and 168 guests