Here’s a solution that may work to solve Samsung GT-I8552 keypad malfunction or not responding.
This solution may help as a guide to repair certain keys that does not working when being pressed. If the device suffered wet or water damaged or any means of liquid most oftentimes that keypad may stop working due to some short circuit occurred and or oxidation may build up due to a liquid residues.
If this happens you may need to clean first the keypad membrane and contact pads using a liquid cleaner.
If all the keypad keys already been cleaned but still there are particular key may still not work, you can used the solution below to trace that particular and check if the connection line paths is not open or cut-off.
Try To Replace His Home Key Flex And Check Its Connections (Stick Well Not)
If They Still Like The Original Check His Path. See The Image Above
Samsung Grand Quattro I8552 Home Button Ways,Home Key Jumpers, Home key not Working problem,Centre Key Ways Solution.