Largest alarm panel manufacturer my ass can’t even put some thermal compund on the chip. That’s cheaply manufactured

You missed a good chance to show how to repair a mess like that. Drill it out? leave the hole? Put boo boo wires around it?

Maxcap aha this is a cheap 85°C Consumer Electronic Electrolytic Cap! NESS is not so like Bosch. No good secure company build in a consumer Electrolytic Cap only 105°C from Nichicon or Panasonic is the solution. See the near distance from the power supply to the GND Layer – unfortunately. Also to mention is the 17V AC – who have developed this board??? I think someone connect the AC 17V to AC 240V that looks like so. The over voltage bring the protection devise on the board to explode.(like a Bi-Directional Suppressor PESD3V3S1UB,115 Nexperia)

so that means circuit also can work without bridge rectifier … nothing new.. thats all

They appear to have put ordinary chip caps in parallel with the Y caps. Did that pass local safety standards?

Just make a little daughter board with the MOVs, caps, bridge rect. Add a two screw 17Vac input header and wire the pos/neg output back to the original bridge rectifiers pos/neg pads. Oh and wire one ac line back to the sense, I'm guessing that's only to sense mains power and display the status on the keypad display. You could then cut as much of the damage out as you want.

Did you ever do a video of you routing this out and repairing it, would love to have seen it up and running again

Disposable board. The alarm main control panel boards are manufactured so inexpensively they have become throw away items. That being said there are times when a bridge rectifier shorts out or an electrolytic capacitor starts to bulge. Then just replace it and be done with it.

A dial up call home feature, you've got ~20s to unplug it (unless it's DSL)…

In a former life I used to do component level repair on alarm circuit boards. For in field failures the #1 failure was a lightning strike on telephone line, #2 was lightning stroke on AC line. A very distant third was every other failure combined.

If you were lucky the input protection parts did there job and you replaced them and the board was in circuit tested and functionally tested. Any severe charring like on this board and it most likely would not have been repaired as there is no way you can guarantee functionality over any reasonable period of time.

Components that are damaged by an overvoltage condition like this my test OK, and work for a short period of time, then you get the same board back a few months later. You don't want a burglar or fire alarm to fail because of a dodgy repair.