I've been doing thru-hole soldering for very many years and also over the past few years some occassional surface mount soldering (both removing and attaching assorted components). I only have basic equipment (temperature controlled soldering iron and rework/hot air station) but I manage just fine without any problems.
However, I've now met my match with a surface mounted connector, a connector type which I successfully removed (a faulty one) and attached (a new one) to a different PCB a few weeks ago. Therefore I've done this procedure before.
The board in question is a motherboard from a Nintendo Switch console, the connector is the USB C connector which acts as a charging port and video/audio output to the Switch's docking station.
Here are some examples of the USB C connector:
As you can see, it has two rows of pins which means that, once placed, the reflow of the already tinned solder pads must go smoothly as there's no way to directly access the inner row once the connector is in place.
In this case, for some unknown reason, I can't get the solder on the pins and pads to reflow AND attach. The heat that I'm applying IS sufficient.
I cleaned up the pads on the PCB, re-tinned them and also tinned the pins on the connector. I then attached the connector, applied hot air, let the solder flow, applied gentle pressure to make good contact between the connector pins and the PCB ..... but for some reason the pins aren't attaching to the pads on the PCB. They ARE making good contact, there IS solder on the pads and the pins as well as flux. So why won't they attach?
I have tried both liquid and gel flux.
I CAN get the external row of pads to attach if I manually heat them with my soldering iron and apply more solder, but of course I can't use an iron on the inner row of pads.
I will say that the old connector was particularly difficult to remove and I had to use a lot of heat to get the metal mounting lugs to free themselves, but the pads looks fine and, I'll re-state this, they DO tin okay.
Any ideas please as to what I'm doing wrong or how I can get this connector to attach?