Try the following:
unsigned int powerOn[] = {2450,500,650,550,650,500,650,550,650,500,700,500,650,550,650,500,1300,500,650,500,700,500,650,500,700};
irsend.sendRaw(powerOn,sizeof(powerOn)/sizeof(powerOn[0]),40);
delay(26);
Explanation:
- you have 25 elements in the array...not 26
- IRremote sometimes adds in a spurious value at the start, which you correctly removed, but did not adjust the count.
- The SONY modulation frequency is usually 40 kHz
- As mentioned the signal is repeated 3 times with a circa 26 millsecond delay in between
- You need to complete the code above to send it 3 times. Then you should stop for at least several seconds as continuously sending a signal may swamp the TV receiver.
As already posted you can just use
irsend.sendSONY(0x010,12);
to send this signal
Finally, point the top of IRLED directly at the TV and bring it closer if neccesssary.
(Read the common pitfalls via my signature)