iPhone 3gs stuck on yellow screen

[xolo10]

i hope someone here can help me
this is my sister in laws phone she bought it second hand and it came with ios 6.1.3. she asked me to jailbreak it so i did. but after i did it turned off by itself and when i attempted to turn it on it didnt. so i used redsnow to do a just boot and it said succesful but on the phone a yellow screen came up and it just stayed there then slowly the screen went black and then it turned off.
i have tried just boot and recovery fix with redsnow i have also tried fix recovery with tiny and nothing has helped. i tried to restore it using itunes to leave it as a brand new phone but it gets stuck on waiting for iphone and doesnt do anything after that. im desperate cuz im scared i might have bricked it. please help me

 

[dhlizard]

Sounds like your battery crapped out.
Charge it overnight on wall charger.
If it won't hold a charge, replace it.

 

[xolo10]

Could the battery be the reason that it just boots up to the yellow screen? As far as I have noticed it doesn't loose charge if I leave it unplugged. Although I did read some articles online that said that the yellow screen came up when it discharged. Well I have another phone which I'm not sure if 3G or 3GS but I will check and if its 3GS I will attempt to change see if it helps. Hope you can answer my question though. Thanks for everything