First I have to press 10 times quickly for one input, now it's completely gone

Try the thoothbrush method without

Succsess, if it a software problem how can I fix it ?,and how much replacement coasts?

You can have a virtual home button on the screen, go to Settings-General-Accessibility-AssistiveTouch and turn it on. Its not ideal but better that nothing.

I had same problem when I bought refurbed 2nd hand iPhone 4 in the UK before coming to LOS. Trawling through various forums revealed this was quite a common problem and too expensive to fix and the suggestion was the same to go into settings and use assistive touch, I have gotten used to doing that and now find it as easy as using the home button.

I have an old 4 lying around unused with the home button not very responsive. Wanted to sell it or trade in against on 4s or 5. Trade in shop told me repair of button would cost 1200 baht, and showed me the part that would be replaced, and pointed me to several repair shops who could do this easily. This was on samui, where everything is more expensive. So pretty sure home button can be fixed for under 1000 baht in bkk.

Search this forum for TAN Telecom - 4th Floor MBK. They will replace it for a few hundred baht.

If your jail broken download Activator and set it to other buttons, I have hold the middle of the status bar for home, double tap for open app switcher, works well loads of combos can be done

Replaced my old iphone 4 home button for 800 Baht so it is not expensive.

I was quoted 300 for the same repair. 2 hours. That's in Chiang Mai.

Allright before everyone asks I'll give the secret away: A small shop called "Mac" on Huay Khao road. In a shophouse going towards the old city, before the Amari Rincome intersection, on the left hand side of the road. Guy's name is Kit, he's the best Mac repair shop in town.