Hi there, I have joined up to these forums just to post this because this is really getting on my nerves. I had bought an iPhone 4S off of eBay for around £40 and the seller has said that it had a problem where the phone would read the SIM card for a short while then switch to No SIM and that would continue as a loop. Reading this, I bought the phone thinking "If it's my luck, it'll switch to read the SIM and I can activate it". Well, my luck is absolutely terrible. It arrived a few days later and I stuck an Orange SIM card into it (that's the carrier it's locked to) and No SIM. I try a different SIM card, No SIM. I go to the Orange store and buy a £10 SIM. No SIM. I thought then that it was the SIM card reader, so I went on eBay and bought one for around £10. It arrived, I looked up on how to replace it, requires soldering. I don't know how to solder, so I'm not going to break a £40 phone by my incompetence. I take it down to a local repair shop and he replaced the SIM reader. It was then after he had replaced it and taken £50 of my money, he said "It is intermittent, it keeps switching from reading the SIM to no SIM". So, I thought "Great, maybe I can get it to read the SIM for 10 seconds and I can activate it finally". Wrong. I've had it on for about two days now, waiting for it to just say Searching, so I can activate my phone. Basically, I thought that it was the SIM card reader but it's not. The repair shop before the one who had replaced the SIM reader said that there was an indicator which had turned black for water damage? I'll attach pictures as to where he said that there was water damage, but somehow I think he's talking through his buttocks. He said that it was where the white area had been scraped, showing black. I don't understand how that could show mater damage though. All I need to know, what could it be? I am somehow thinking maybe it's the battery, but to be honest, I hardly know anything about the internals of an iPhone. Thank you.