my friend i can tell you water damage iphone almost NEVER works 100percent with just a simple "cleaning" you have to have knowledge of circuits, active/passive components , memorize schematics and still need a little luck; there is not one elemental "single" circuitor component to trigger error 21- there are several dozens paths of circuitry that will give error 21 or 16xx but you can start by looking at all the caps around U52 and U1 but if there is short or disconituity you must readyto reball- and did you know there are several layers of PCB in iphone if short or break is within the board you are screwed-listen you say you have experience but you dont sound like it , you should not be asking naive question to Wites it get him angry lol |