Solder that won't melt.

[xavier60]

In the photo it can be seen what looks like a solder bridge across a bunch of pins on the micro-controller. It is the motor controller board of Fisher & Paykel washing machine.
Whatever it is, I could not remove it with solder wick even after adding fresh solder and also adding chip quik smd removal alloy in an attempt to dissolve it.
I eventually scraped most of it out with a sewing needle and lifting 2 pins to clear a stubborn short.
The board is one of a bunch that I scored from a Gumtree seller, so I don't know much of its history except that the SMPS transformer had been removed revealing a badly charred LNK624 SMPS IC.
I'm really curious about what type of metal it's likely to be and how it got there. Maybe someone has seen the same thing.

[DaJMasta]

It looks like the board is potted, so there's probably a layer of sealant on the pins that's just preventing good metal-to-metal contact.  Try chipping it off with a sharp knife (lightly enough not to chip the pins off too) and see if you can make better contact.

[capt bullshot]

Yes, IMO it's the remainders of the conformal coating that interferes with your soldering.

[Rerouter]

Its a common industrial conformal coating, acetone and a toothbrush will clean it off pretty quickly,

The solder itself will be lead-free so should melt by 360C, but the coating is somewhat thermally insulating, which prevents you being able to get enough heat into a joint.

[xavier60]

It looks like the board is potted, so there's probably a layer of sealant on the pins that's just preventing good metal-to-metal contact.  Try chipping it off with a sharp knife (lightly enough not to chip the pins off too) and see if you can make better contact.

There was a light coating of lacquer that I had applied before I knew about  the bridged pins.
I took the photo after the first 2 attempts of applying a large blob of solder to the group of pins and removing it with solder wick. That remaining metal between the pins was rather tough yet brittle.