Modern power supplies are quite complex devices with a variety of electrical, noise, weight, size and thermal characteristics. ATX power supplies are switching converters with different circuit solutions and a single principle of operation. To check their performance, it is necessary to prepare special test equipment.
Necessary
- - tester;
- - oscilloscope.
Instructions
Step 1
Arm yourself with an ATX power supply wiring diagram. It may be in the instructions that were sold with the device. If there is none, then you can find this scheme on the Internet at specialized sites. For example, you can use the information on the site
Step 2
Start by checking the high-voltage side of the ATX power supply, which includes: fuse, coils, protective thermistor, high voltage electrolytes, diode bridge, transformer primary winding, power transistors, controls in the base circuit of power transistors. Check these elements with a tester for open and short. If you find a problem, then replace all non-working parts of the power supply.
Step 3
Proceed with a safe check of the power section of the unit. It must be carried out only after the above non-working elements have been replaced. For this test step, you will need a 36V secondary transformer. Connect it to the power supply so that the output of the diode bridge is 50-52V. Check the voltage across each electrolyte and between the collector and emitter, which should be half the 50-52V.
Step 4
Call the ATX power supply units on duty. Check transistors and diode bridges for shorts and open circuits.
Step 5
Take a 12V stabilized power supply and plug into an ATX power supply to test the control circuit. Take the waveform readings at the appropriate terminals.
Step 6
Check the output voltage of the ATX power supply. It is necessary to identify the presence of voltage instability under dynamic load, the device's own ripple and other characteristics. To facilitate this task, you can connect the unit to a working motherboard.
