Going to have to fix or replace the front panel board. You didn't say which size. There are Various Sizes MT (Mini Tower)DT (Desktop)MFF (Micro Form Factor)SFF (Small Form Factor)USFF (Ultra Small Form Factor) [IMAGE]                       Beware of DELL OPTIPLEX (N-SERIES) which DO NOT HAVE AN OS.The n Series is a Dell product line that does not ship with a pre-installed version of Microsoft Windows. Apparently prohibited from shipping computers without an operating system by an existing licensing agreement with Microsoft, Dell instead ships these systems with either the open-source FreeDOS operating system or the Ubuntu Linux distribution not preinstalled, but on install disks. In addition to these Designation there are Some Series that only have 3 or 4 Sizes instead of 5 Regulatory Model and Type Dell OptiPlex 7060 Tower, Model D18M,  Type D18M005Dell OptiPlex 7060 Small Form Factor, Model D11S, Type D11S004Dell OptiPlex 7060 Micro Form Factor, Model D10U, Type D10U003   Dell OptiPlex 9020 Mini-Tower, Model D13M, Type D13M001Dell OptiPlex 9020 Small Form Factor, Model D07S, Type D07S001Dell OptiPlex 9020 Ultra Small Form Factor Model D06U, Type D06U001Dell OptiPlex 9020 Micro Form Factor Model D09U, Type D09U001 There was also a FLEX designation  11 Year Old Models from 2008Regulatory Model (Mini-Tower): DCSM or DCSM1FRegulatory Model (Desktop): DCNE or DCNE1FRegulatory Model (Small Form Factor): DCCY or DCCY1FRegulatory Model (Ultra Small Form Factor): DCTR or DCTR1F [URL] Models Like GX1 or GX110 (26 years Old)MMP = mini tower (MT) chassis (Trapper) 200 watts powerDCM = midsize desktop (M) chassis (Hunnicutt) 200 watts powerDCS = low profile (L) chassis (Hawkeye) 110 watts powerDCP = small form-factor (SFF) chassis (Gator) 085 watts power         Newer Has TOWER SMALL and MICRO     Micro Form Factor       What do they Look Like       960 970 980 3010 7010 9010 3020 7020  9020 Etc       DELL FREEDOS  
I have had it for about 5 years+ and recently the front headphone jack caved in on itself (It's stuck inside the pc). So then I tried using the rear headphone jack, (the green one because the color of my speaker's tip matches it) and it still doesn't work. Does anyone know of a way to fix this?
Optiplex 780 sound