What Voltages To Expect From The Secondary Output Of SMPS

Is the secondary output voltages important? Yes definitely, in fact all these output voltages are the testing point to check how well is the SMPS. That means by just placing your test probe on those output pins you would know if the SMPS is working good, bad or have intermittent problem. The question now is what if you have not repair that type of SMPS before? What are the voltages you should expect? Its easy, just look at the working voltage of the filter capacitors. If the filter capacitor is rated as 1000uF 25 VOLT then you can expect the output voltage somewhere from 14 to 18 volts. If you get about 5 to 6 volts then you know the SMPS is not producing the right voltage. The marking on the filter capacitors is a very good indicator of what output voltages that you should expect.


If you are repairing the Monitor SMPS, then surely you will know what output voltages to expect because CRT Monitors generally have a standard heater voltage which is 6.3 Volt DC. Not only that if you are checking the Boost circuit (that consist of B+ coil, B+ FET, B+ Diode, B+ Filter capacitor and current sense resistor) voltage line then you can expect about 45 to 50 VDC. If you get lesser than that say 25 volt, this clearly indicates the SMPS or the secondary side components that had caused the output to go low. This you have to troubleshoot and find it out with your troubleshooting skill.

Assuming you have not repair any Monitor (it can be other type of electronic equipment) before, what you need to do is to download the Monitor schematic diagrams and compares each of the SMPS output voltages so that you will roughly know what voltages a CRT Monitor can produce. Use this way to apply on other types of SMPS to locate the right output voltages.

Sometimes one have to spare some of their precious time to do their own research as with this way you will become independent faster than you can imagine. Without any sacrificial of your own time, you will only get slower result and this will overall affect your skill in electronic troubleshooting. Always think of a way that can help you to repair faster with accurate result either with the help of test equipments, coming out your own universal schematic diagram for a particular equipment or even from your own research and development (R & D). All the best to you