Bought a secondhand SG gt s5830t from ebay. The seller has dropped it on the ground and broken the glass. He has replaced it. The phone can be switched on but goes off after few seconds. At times when the power button is pressed, can see a faint light but does not go to samsung logo and beyond. I replaced the digitiser and the phone is working again. However the Volume key does not work. If I play a music file on the default player, can't increase or decrease the volume. Same with ring tones, radio etc. Although I can adjust the volume from the 'setup' menu, I cant do it using the volume button. Because of this problem I can go to 'download mode'. Can go to recovery mode, but can't scroll up or down using the volume key. When I dismantled the phone to replace the digitiser, I checked on the ribbon cables for the volume button, power button and the mike. They seem to be ok. When I press the volume up/down I can hear the key making contact so there is nothing wrong with key contact. I did a hardware reset with no result. It is a locked phone. Please let me know whether it is a hardware problem requiring the volume key assembley fpbs to be replaced? I have searched the forum and could not find any thread describing this problem and any solutions. Many thanks in advance for this lengthy post.