![Dell Optiplex 740 '123' front error light's and orange light inside? - Troubleshooting - Linus Tech Tips Dell Optiplex 740 '123' front error light's and orange light inside? - Troubleshooting - Linus Tech Tips](https://linustechtips.com/uploads/monthly_10_2014/post-78406-0-05714500-1414491760.jpg)
Dell Optiplex 740 '123' front error light's and orange light inside? - Troubleshooting - Linus Tech Tips
Solved: Dell Optiplex 780 Error Messages/Diagnostic Codes Power Button and then 1 and 3 number lights flash - Dell Community
![I got this old Dell Optiplex 780 for free from an office and when the power button is held down and error code of 3 appears and the power buttons doesn't light I got this old Dell Optiplex 780 for free from an office and when the power button is held down and error code of 3 appears and the power buttons doesn't light](https://i.redd.it/9ko0xoaf41h31.jpg)
I got this old Dell Optiplex 780 for free from an office and when the power button is held down and error code of 3 appears and the power buttons doesn't light
Solved: Dell Optiplex 780 Error Messages/Diagnostic Codes Power Button and then 1 and 3 number lights flash - Dell Community
OptiPlex 780 - Steady orange power button light + numbers 1 and 2 blink every 1.5-2 seconds. - Dell Community
![Guide] macOS High Sierra 10.13 - Dell Optiplex 780 (760) (755) (790) (990) - Page 6 - Installation Guides | InsanelyMac Guide] macOS High Sierra 10.13 - Dell Optiplex 780 (760) (755) (790) (990) - Page 6 - Installation Guides | InsanelyMac](https://www.insanelymac.com/uploads/monthly_2018_05/check.png.2967b91f222b52ec52cd4703aa4d5e1f.png)