I have a Thermaltake 750 watt PS that is 6 years old just wondering if I should be looking at a new one. What is the life span on these things? Years ago I had an OEM PS and it died and took my old Slot A motherboard with it. Gun shy ever since. Thanks.
It's better safe than sorry, and especially if you are planning on some hardware changes in the near or distant future. Last thing you want to do is kill a component in your box, and worse yet a shiny new part in your box.
Replace it. It's probably fine, it will lose output capacity over time (for example, it may only be capable of 600W now, which is still enough to run a PC) you can keep it on hand as a spare as long as you keep in mind that it won't output 750W, and don't rely on it too long.