I installed water proof LED 5630 strip lighting under my kitchen cabinets. I used a kit of sorts with a small transformer and a remote dimmer switch. Initially, it worked, but flickered at the end of the run. An electrician suggested I remove the remote dimmer, so I installed an in line on/off switch. That didn't help, so I purchased a different transformer at 12V/5A capacity. The lights are now real dim with the end of the run not lighting. The "run" is: 40" of single strand double wire from transformer to 41" light strip...170" of multi strand speaker wire going up in attic, over sink, then down and to a 20" light strip...then jumpered to 22" light strip...jumpered to another 22" light strip...jumpered to 57" light strip. I checked the transformer on a 5 meter length of strip lights and it worked fine. I'm not sure what my next step should be, and any help is appreciated.
You're run is too long. Each LED strip will draw considerable current and add quite a bit of resistance to the run. You don't say what gauge wires you have in between, but here is a rough guide for how far you can run a 12V line:
24 AWG 22 AWG 20 AWG 18 AWG 16 AWG 14 AWG 12 AWG DC 100mA 216 feet 342 feet 594 feet 867 feet 1,379 feet 2,197 feet 3,508 feet DC 200mA 108 feet 171 feet 297 feet 433 feet 689 feet 1,098 feet 1,755 feet DC 300mA 72 feet 113 feet 198 feet 289 feet 459 feet 732 feet 1,169 feet DC 400mA 54 feet 85 feet 148 feet 216 feet 344 feet 549 feet 877 feet DC 500mA 43 feet 68 feet 119 feet 173 feet 275 feet 439 feet 701 feet DC 750mA 28 feet 45 feet 79 feet 115 feet 183 feet 293 feet 467 feet DC 1000mA 21 feet 34 feet 59 feet 86 feet 137 feet 219 feet 350 feet
Basically, speaker wire is relatively thin and LED strips draw considerable current. If it were me I would probably not daisy chain all the strips together. Try wiring them in more of a star topology where each new LED strip connects to a splice off from a single voltage bus (wire). Consider upgrading your power carrier to a 12 or 14 gauge wire.
The current draw will depend on the actual number of LEDs in each strip, but from the distance you've quoted you might be very close to or over the 5A of the transformer.