My system has 16GB of DDR3, an Intel i7-3770, a GTX 750 Ti, and a fairly new 500W power supply. The computer powers on but repeatedly gives four beeps and does not appear to initialize USB devices or complete POST. I tested the memory sticks individually in different slots, cleaned the contacts carefully, and tried resetting the CMOS by removing the motherboard battery before reinstalling it. Interestingly, my mouse lights up when connected, but nothing else seems to start normally. I have also reseated the power cables and removed the graphics card and SSDs while troubleshooting. Could four beeps indicate something other than faulty RAM, and what should I test next?
3 Answers
The CMOS battery usually preserves settings and will not normally cause a persistent four-beep POST failure. Replacing it is harmless, but it probably will not fix this symptom. Since the system is older and several components could have failed, the most useful next step is testing with another compatible power supply or motherboard, rather than buying random replacement parts.
Four beeps do not have one universal meaning; the exact code depends on the motherboard and BIOS manufacturer. On some systems it indicates a system timer or motherboard fault rather than memory. Check the board or system manual for the beep-code table if possible. A CMOS reset is different from simply removing the battery briefly, so follow the board's clear-CMOS procedure with the power disconnected.
I did remove the power and leave the battery out for a while, but I’ll look for the proper clear-CMOS pins and the board’s specific beep-code information.
Try a bare-minimum POST setup: motherboard, CPU and cooler, one known-good RAM stick, power supply, and the case speaker. Disconnect the drives, USB devices, and graphics card if the processor has integrated graphics. Test each memory slot and make sure the 24-pin motherboard and 4/8-pin CPU power connectors are fully seated. If the four beeps remain with known-good memory, the likely suspects are the power supply, motherboard, or CPU rather than the SSDs or GPU.
The graphics card and drives being removed won’t usually cause this particular code. Focus on getting a minimal POST with the board outside the case if necessary, and check for loose screws or a short underneath it.