Chosen Solution
Full re-build, new back, new audio socket harness, new battery, new glass. Re-build complete, turned on, only get Apple logo (no timer) which will not disappear. Have tried connecting to iTunes and using hard re-set, but nothing. Any ideas anyone? My daughter is giving me a hard time as it is her phone!!
There is something that you just installed that could be causing this. I would try replacing the battery with the original one first. Sometimes it could be something as simple as a defective battery. Continue with the troubleshooting this way. There are certain ribbons you dont need to get the phone to boot. Ribbon #5 is the power button, but you can get it to boot by plugging it in the charger/computer. Like the other guy I told, try the #3 connector. Sometimes if this is kinked or damaged, it could easily cause boot issues. see my answer here: Will not boot past apple logo!
