Sir,
I have the same problem with my two computer SMPS. Output voltage of all the wires are correct (3.3v and 5v), except +12v and -12v. This section returns +11.3v and -11.3 volts instead.
Please tell me how to solve the problem.
But these two SMPS (output voltage +11.3 & -11.3)are not working while the new one is working. When i connect the faulty SMPS with computer, computer is not being even switch on. Will you please describe about the fault occured?
Did the computer ever work with the two SMPS that you describe? For how long? Kind-of odd if they are exhibiting the same 'fault'. Are you measuring the voltage levels with the SMPS connected to the computer?
Are the two SMPS designed to handle the power requirements of the computer? Are they the same model? Is the third PSU designed for higher load?