I've recently broken the on/off switch for the backlight and I'm not sure how it functions so I can fix it.

 

Less seeing the rest of it my guess is that it was a DPDT (Double Pole Double Throw) slide switch. The center contacts would make contact with the top or bottom pads which are left. Do you have the pieces? A Google of DPDT Slide Switch should bring up images of what it may have been and again it's only a guess on my part.

Ron

 

First: THIS IS JUST A GUESS!
Now: on the surface, it looks like a DPDT Slide switch. The black outlines represent the contacts within the switch and their legs soldered to the PCB. The blue rectangles highlight the slide marks from the switch being toggled between ON and OFF. The one thing that I DO NOT KNOW is the yellow rectangle. IT LOOKS like yet one more point of contact. So it might be a specialty switch. But again, this is just a guess.

When the switch is slid toward the ON position the OFF position makes no contact with anything. But when it's slid to the OFF position it definitely makes contact with the four bottom legs. And possibly between the two bottom pins as well. I've never seen anything like that, but then again, there's literally thousands of switches out there. Most are just simple switches, but there are also a large number of specialty switches. IF the yellow rectangle represents another point of contact then this would be a highly specialized switch, one that is best suited for the purpose in which it is being used. Do you still have the broken part? If so - a picture will clear up this mystery (for me at least).

 

When ON, pins 1 & 2 make contact, and pins 5 & 6 make contact. Pins 3 & 4 do not make contact with anything else.
When OFF, pins 2 & 3 make contact, POSSIBLY 3 & 4 make contact, and 4 & 5 make contact. Pins 1 & 6 do not make contact with anything else.

 

Buy another and solder on...
https://www.sparkfun.com/products/597
AYZ0202AGRL
https://www.sparkfun.com/datasheets/Components/SW_slide_ayz.pdf (2nd page top)
(Verify solder pad spacing to verify physical match)

 

Thank you so much for your responses.
You were all a big help.
I managed to "fix" it using tinfoil and tape however it displays with "no signal" after plugging in my HDMI. Perhaps I can change the HDMI module on the circuit but I don't have the tools to do so.
Many thanks <3

 

When ON, pins 1 & 2 make contact, and pins 5 & 6 make contact. Pins 3 & 4 do not make contact with anything else.
When OFF, pins 2 & 3 make contact, POSSIBLY 3 & 4 make contact, and 4 & 5 make contact. Pins 1 & 6 do not make contact with anything else.
View attachment 275840

After many attempts it seems if I make a connection between 1 & 2 it works so it's confused why even 6 & 5 is needed.
Anyway big help thanks <3

 

Probably because the original switch made that contact, if you leave it open that could be a part of why you get "No Signal". "On" is one thing and just means the circuit is powered. "No Signal" MIGHT mean that something that is connected by 5 & 6 is not being detected. Really, without knowing all the details of how that switch functions and what each circuit does - I can hardly guess as to why you're getting an error message.