My GTX 1660 suddenly died a few weeks ago, so I temporarily used an older GT 720. I recently installed a used RTX 3070, which initially worked perfectly. Since the 3070 only has one HDMI port, I connected my main monitor to it and kept the GT 720 installed to drive my other two monitors. After roughly 5–10 minutes, both monitors connected to the GT 720 lost signal at the same time, while the monitor connected to the 3070 continued working. There was no warning beforehand, similar to what happened with the 1660. The GT 720 is quite old, but two GPUs failing in a similar way has me worried that the power supply or unstable household electricity could be damaging hardware. My area has also experienced several power outages recently. What should I check first, and should I stop using the PC until I replace the PSU or add a UPS?
2 Answers
Recent outages make power problems more plausible. A good UPS with automatic voltage regulation can help protect the computer from outages and voltage fluctuations, but it should not be used to compensate for a questionable PSU. Replace the PSU first if it’s suspect, then consider a quality UPS—ideally one designed for computer equipment and sized for the system’s actual load.
The GT 720 is an old Kepler-era card, so it may simply have reached the end of its life, especially if it was already used heavily. However, the matching failure pattern is enough reason to take the PSU seriously. For the monitor setup, you may not need the second GPU at all: many RTX 3070 models have DisplayPort outputs, and a proper DisplayPort-to-HDMI cable or adapter can drive the other HDMI monitors. Check the exact ports on your particular card before buying anything.
A dedicated DisplayPort-to-HDMI cable is generally preferable to a cheap adapter and should be more reliable for this kind of setup. An HDMI splitter is another option, but it would normally mirror one display rather than provide three independent desktops.
I hadn’t considered a UPS before, but the outages have been unusually frequent here. I’ll look into one after confirming that the power supply itself is reliable.