referencias:
14
https://www.dell.com/support/article/us/en/19/sln288646/optiplex-3020-visual-guide-to-your-computer?lang=en
https://topics-cdn.dell.com/pdf/optiplex-3020-desktop_Owners-Manual2_en-us.pdf
https://www.dell.com/support/article/us/en/19/sln288898/optiplex-3020-small-form-factor-sff-cru-customer-replaceable-parts-removal-guide?lang=en#Removal_Guide
https://www.dell.com/support/article/us/en/19/sln289331/optiplex-740-small-form-factor-sff-removal-guide-for-the-memory-heatsink-power-supply-system-fan-and-front-io-panel?lang=en#Third_Removal