Iphone shuts off randomly with camera and sound iPhone 4S

infamousxx wrote:

...I have already replaced the battery but still does it....

Does anyone have any advice on troubleshooting hardware?    I am knowledgable in repair and modfication of electronics, can solder and use a multimeter/volt meter.

Try having a look at iFixit.com.  The iPhone is not considered user servicable. There is no such thing as a legitimate source for parts for an iPhone. Apple does not sell parts. The only possible sources are:

1. Salvaged from broken/discarded/stolen phones.

2. Fakes

3. Defective castoff parts stolen from one of Apple's suppliers.

Thanks for the reply.  I plan on salving parts from other broken iphones,  but i just need help verifying what exactly is causing the issue so I dont buy a bunch of parts and not fixt the problem.   

Im thinking it has something to do with the logic board cuz it works fine when plugged in.