You need a (costs about $15-20). Do not use software voltage readings; they are often inaccurate.
One paperclip. The danger: You are dealing with live electricity. Do not touch metal parts while the PSU is plugged in. check power supply on pc
Before you buy a new $500 graphics card, you should check if your old $50 power supply is the real culprit. Here is your practical guide to diagnosing PSU issues. Use this if: Your PC is completely dead (no fans, no lights). You need a (costs about $15-20)