My Thermaltake Toughpower Grand RGB 850W PSU flashes red when I push the power button but the computer does not turn on. The lights on the motherboard come on like normal when the switch on the PSU is on but no fans spin up and no beeps are emitted when I hit the power button.

marked as duplicate by DavidPostill Apr 17 '18 at 21:58

This question was marked as an exact duplicate of an existing question.


This is typically an indicator of a problem with the power supply's ability to output properly. PSUs with indicators are made in such a way that if they have a serious problem they will not activate, but will supply enough power to their LEDs to tell you they are a) receiving power and b) malfunctioning. Unfortunately, Thermaltake's manual isn't very helpful in troubleshooting these conditions; it's little more than an installation guide.

A few things can cause this.

  1. If you are using splitters on your power supply cables, you may be overloading a rail. Make sure you are using connectors to the rail ports in the power supply and not just splitting the in-built rails over and over.
  2. As mentioned in (1), that PSU is modular. Try shifting accessories over to another rail. Balance the power across the components so that no one rail is doing the heavy lifting by itself on your accessories and components.
  3. Surge damage or other critical faults internal to the supply can still allow the PSU to power the LED for a moment in order to flash a warning. This is because LEDs require little to no power to operate and are rarely behind much circuitry within the unit.
  4. A badly connected or faulty component can cause this. Disconnect everything except for the motherboard, CPU, and (if you're sure it's OK) the GPU connectors and see if the machine boots. If it does, you may have had something connected improperly or a damaged component that is causing failsafes in the the PSU to trip.

If shifting accessories to other rails and swapping out your modular cables doesn't do any good, it's a safe bet the power supply has bought the farm. If it's within warranty, contact Thermaltake. If it's DOA, contact your retailer.

However, I just read your other post that was locked as "too broad". You should have just edited that post. It sounds like your motherboard may be the faulty component mentioned above. I'd order a new one.

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