I'm trying to revive a used Dell OptiPlex 9020 that powers on but shows a front-panel LED blink code of 3-5 and produces no video output. The power supply's built-in test LED stays lit, and the CPU warms up normally. I inspected the power supply after cleaning out a large amount of dust, but found no obvious damage such as burned components, cracked solder joints, or swollen capacitors. The CPU has no bent pins.
The system came without memory or storage, so I installed my only 1GB Samsung DDR3 module. That module has been dropped several times and has a tiny damaged-looking area near one corner, although there is no other visible damage. Removing the RAM causes the computer to beep for missing memory, but installing it results in the 3-5 blink code and no display. I have also disconnected the drives, front USB connections, DVD drive, and other internal peripherals, leaving only the essential components connected. I don't currently have another RAM module to test, and the power supply uses a proprietary connector, so swapping it is difficult.
The system has an Intel Core i7-4790 and integrated graphics. Does the 3-5 code most likely indicate that this RAM module is faulty or incompatible, or should I continue troubleshooting another component?
1 Answer
On the OptiPlex 9020, a 3-5 diagnostic blink code generally points to a memory problem or an invalid RAM configuration. Since the system has no display, it is likely failing during POST before it can initialize video. Test the memory one module at a time, and if possible, try a known-good compatible DDR3 module. The fact that removing the RAM produces the expected missing-memory beeps does not prove that the installed module is working; it only shows that the system can detect that no memory is present.
The module turned out to be bad. I installed a different DDR3 module, and the computer now works.