The schematics mention diode zd930 (audio power output) but the bill of materials does not mention zd930 and there is no part number. I found GDZ20B but they are all surface mounted - the one on the board is not. Does somebody have the part number?
Unfortunately, Dell does not repair monitors, sell monitor components, or have disassembly documentation. Nor do we have any part numbers for monitor internal components. You should do a google search for "2209WA repair" and see what other users may have discovered.