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A good friend of mine forgot his ipod touch 4g in his pants, now his mother washed it in the machine. The only way too turn it on is to plug it with the power adapter. In the touchscreen you can see water spottings at some areas. I think the battery died and i have to change it with a new one. But can i fix the display in this way to get a clean picture again or do i have to change it to for a new one?
It looks to me like you need to at least replace the battery. That is a must. You can also replace the screen assembly in order to regain a clean picture. Of course you need to also disassemble your ipod and clean it well with isopropyl alcohol and a small brush. Make sure that clean the contacts and cables as well. It is okay to use a hair dryer on the coolest setting to expedite the drying process. Visually inspect the ipod for any damage to the components due to the water and laundry soap. this is all very important and essential. Once you have it cleaned and dried, re-assemble and try with a new battery and see what you get. The parts are available here and many other places online. Good Luck.