Blinking Orange Light Only
Computer fails to come on.
Adding a video card
lots of water damage!
Background and Identification
The OptiPlex 755 is a series of four desktop business computers each with a different size case. The largest version is the mini-tower, abbreviated “MT.“ Getting smaller, the other sizes are called the desktop (DT), the small form factor (SFF), and the ultra small form factor (USFF). The computers have many features designed for businesses such as a low energy footprint and TPM (trusted-platform module) hardware encryption. For anyone interested in tinkering with their machine or adding new hardware, the case of the OptiPlex 755 is easy to open.
Due to the size constraints, each computer can accommodate a different number of hard drives, as shown below in the specifications. The computer has expansion slots so you can upgrade the graphics card to your needs or add faster connections than the built-in USB 2.0. All the models have four memory slots (except the USFF which has only two) which can accept up to 2 GB each. The standard-sized hard drive and optical drive bays can accept any type of SATA drive, so you can repair and upgrade these components easily.
You can identify the OptiPlex 755 by looking for the Dell logo on the front or side of the device. Find the service tag (a seven digit code of letters and numbers) written on a sticker on the back or side of the computer. You can enter this tag on Dell’s support website to find more information about your hardware.
- Intel Celeron 430 or 440
- Intel Core 2 Duo E2140, E2160, E2180, E4400, E4500, E4600, E6550, E6750, or E6850
- Intel Core 2 Quad Q6600 or Q6700
- Four DIMM slots (except for USFF which has two)
- Up to 2 GB sticks in each slot
- DDR2 SDRAM at 667 MHz or 800 MHz
- MT: two 5.25-inch bays, three 3.5-inch bays (two internal)
- DT: one 5.25-inch bay, two 3.5-inch bays (one internal)
- SFF: one 5.25-inch bay, two 3.5-inch bays (one internal)
- USFF: one 3.5-inch bay (internal)
- Intel Graphics Media Accelerator 3000
- Optional dedicated graphics:
- ATI Radeon HD 2400 XT
- ATI Radeon HD 2400 Pro
- ATI Radeon X1300
- Two front USB 2.0 ports
- Six rear USB 2.0 ports (only five for USFF)
- Rear serial port
- Rear parallel port
- Gigabit Ethernet port
- VGA or DVI video port
- 3.5 mm microphone jack on front
- 3.5 mm headphone jack on front
- 3.5 mm line input on front
- 3.5 mm speakers line out on rear
Dell OptiPlex 755 support page
Dell OptiPlex 755 user’s guide
OptiPlex 755 specifications from Dell