WEBVTT 1 00:00:00.080 --> 00:00:03.000 In this lesson, we are going to talk about power issues 2 00:00:03.000 --> 00:00:05.040 you may experience with a system. 3 00:00:05.040 --> 00:00:07.650 Now, as you start to troubleshoot issues with a computer, 4 00:00:07.650 --> 00:00:09.090 the first thing we have to look at is, 5 00:00:09.090 --> 00:00:11.190 does it get proper power? 6 00:00:11.190 --> 00:00:13.950 Now, there are six main causes of power issues 7 00:00:13.950 --> 00:00:17.280 and why a system won't boot up when you try to turn it on. 8 00:00:17.280 --> 00:00:18.450 This includes, the power button 9 00:00:18.450 --> 00:00:20.700 not being connected properly to the motherboard, 10 00:00:20.700 --> 00:00:22.110 the wall outlet being faulty 11 00:00:22.110 --> 00:00:23.970 or not providing adequate power, 12 00:00:23.970 --> 00:00:24.803 the power cable 13 00:00:24.803 --> 00:00:27.600 going from the wall outlet to the computer being faulty, 14 00:00:27.600 --> 00:00:29.760 the power supply itself being faulty, 15 00:00:29.760 --> 00:00:31.560 the power cables going from the power supply 16 00:00:31.560 --> 00:00:33.330 to the components being faulty, 17 00:00:33.330 --> 00:00:35.340 or there's an incorrect voltage setting 18 00:00:35.340 --> 00:00:37.330 on the power supply unit itself. 19 00:00:37.330 --> 00:00:39.480 Let's take a look at each of these. 20 00:00:39.480 --> 00:00:41.040 First, we have the power button 21 00:00:41.040 --> 00:00:43.590 not being properly connected to the motherboard. 22 00:00:43.590 --> 00:00:45.480 Now, when you try to turn on a computer, 23 00:00:45.480 --> 00:00:48.000 the first thing you're going to do is press the power button. 24 00:00:48.000 --> 00:00:49.050 Now, when you do that, 25 00:00:49.050 --> 00:00:51.119 the power button is going to send an electrical signal 26 00:00:51.119 --> 00:00:53.730 from the button down to the motherboard, 27 00:00:53.730 --> 00:00:56.040 and, therefore, it has to be actually connected 28 00:00:56.040 --> 00:00:57.450 to the motherboard. 29 00:00:57.450 --> 00:00:58.800 The buttons on the computer case 30 00:00:58.800 --> 00:01:00.360 have to be connected to the motherboard 31 00:01:00.360 --> 00:01:03.000 in order for this system to be able to boot up properly. 32 00:01:03.000 --> 00:01:05.820 And, if that wire becomes unattached to the motherboard, 33 00:01:05.820 --> 00:01:07.320 it's not going to be able to send that signal 34 00:01:07.320 --> 00:01:09.990 or have the signal received by the motherboard. 35 00:01:09.990 --> 00:01:12.060 So it's important to check this. 36 00:01:12.060 --> 00:01:14.400 If you push the power button on the front of your computer 37 00:01:14.400 --> 00:01:16.520 and it doesn't turn on, this could be an indication 38 00:01:16.520 --> 00:01:19.581 that that wire is no longer connected to the motherboard. 39 00:01:19.581 --> 00:01:22.440 In order to troubleshoot and identify this as the problem, 40 00:01:22.440 --> 00:01:24.240 you're going to have to open up the computer. 41 00:01:24.240 --> 00:01:25.200 So you want to make sure 42 00:01:25.200 --> 00:01:27.150 you unplug the computer from its power source, 43 00:01:27.150 --> 00:01:28.470 such as the wall outlet, 44 00:01:28.470 --> 00:01:30.270 and then you can open up the computer, 45 00:01:30.270 --> 00:01:33.060 and follow the wire from the button to the motherboard, 46 00:01:33.060 --> 00:01:34.800 and verify it as properly connected 47 00:01:34.800 --> 00:01:37.469 and fully seated into the motherboard's connector. 48 00:01:37.469 --> 00:01:41.100 Second, we have the wall outlet itself being faulty. 49 00:01:41.100 --> 00:01:41.933 Now, when this happens, 50 00:01:41.933 --> 00:01:43.688 this means you're not getting adequate power 51 00:01:43.688 --> 00:01:46.590 from your building into your computer. 52 00:01:46.590 --> 00:01:47.640 So to test this, 53 00:01:47.640 --> 00:01:49.110 you're going to have to use a multimeter or voltmeter 54 00:01:49.110 --> 00:01:51.480 to be able to test the power outlet 55 00:01:51.480 --> 00:01:54.030 and verify you're getting the proper amount of voltage 56 00:01:54.030 --> 00:01:55.980 at the right hertz cycle. 57 00:01:55.980 --> 00:01:57.450 Now remember, wall outlets 58 00:01:57.450 --> 00:01:59.640 will provide two different levels of voltage 59 00:01:59.640 --> 00:02:01.830 depending on where you're located in the world. 60 00:02:01.830 --> 00:02:03.280 If you're in the United States or Canada, 61 00:02:03.280 --> 00:02:04.860 you should expect to see somewhere 62 00:02:04.860 --> 00:02:09.060 between 110 to 120 volts AC, at 60 hertz. 63 00:02:09.060 --> 00:02:10.980 But, if you're in Europe or Asia, 64 00:02:10.980 --> 00:02:12.150 you should be expecting to see 65 00:02:12.150 --> 00:02:15.840 220 to 240 volts AC, at 50 hertz. 66 00:02:15.840 --> 00:02:17.550 In order to test your wall outlet, 67 00:02:17.550 --> 00:02:19.770 you'll simply connect your red and black leads, 68 00:02:19.770 --> 00:02:21.330 which are your positive and negative, 69 00:02:21.330 --> 00:02:23.301 to the appropriate terminals on the wall outlet 70 00:02:23.301 --> 00:02:25.570 and read the amount of voltages being output 71 00:02:25.570 --> 00:02:28.830 by looking at the display on your multimeter or voltmeter 72 00:02:28.830 --> 00:02:31.770 to verify that it is the correct amount that you expect. 73 00:02:31.770 --> 00:02:33.810 Now, the third power issue often occurs 74 00:02:33.810 --> 00:02:34.920 because the power cable 75 00:02:34.920 --> 00:02:37.140 going to the computer from the wall outlet 76 00:02:37.140 --> 00:02:39.900 has become faulty or frayed over time. 77 00:02:39.900 --> 00:02:42.480 To test this, you want to disconnect that power cable 78 00:02:42.480 --> 00:02:44.208 from the wall outlet and the computer, 79 00:02:44.208 --> 00:02:48.390 take your multimeter and run a resistance check across it. 80 00:02:48.390 --> 00:02:51.060 To be able to do this, you'll simply place one of your leads 81 00:02:51.060 --> 00:02:52.560 on one of the prongs on the cable 82 00:02:52.560 --> 00:02:54.390 and the other lead into the hole 83 00:02:54.390 --> 00:02:56.250 on the other side of the cable. 84 00:02:56.250 --> 00:02:57.360 This will be able to verify 85 00:02:57.360 --> 00:03:00.030 that you have full continuity across that cable. 86 00:03:00.030 --> 00:03:01.020 Now, when you do this, 87 00:03:01.020 --> 00:03:03.240 you need to do this three separate times, 88 00:03:03.240 --> 00:03:04.680 once for the positive pin, 89 00:03:04.680 --> 00:03:05.910 once for the negative pin 90 00:03:05.910 --> 00:03:07.770 and once for the grounding pin. 91 00:03:07.770 --> 00:03:09.720 Now, once you verify there's proper continuity 92 00:03:09.720 --> 00:03:12.167 across each of the three wires inside of that cable, 93 00:03:12.167 --> 00:03:13.620 you know that that cable 94 00:03:13.620 --> 00:03:16.290 is no longer the issue of your power problem. 95 00:03:16.290 --> 00:03:17.610 Now, when you're reading the resistance 96 00:03:17.610 --> 00:03:19.847 across each of these wires inside of the cable, 97 00:03:19.847 --> 00:03:22.037 you should be expecting to get zero ohms 98 00:03:22.037 --> 00:03:24.390 or very close to it. 99 00:03:24.390 --> 00:03:27.270 On the other hand, if there's a break in one of those wires, 100 00:03:27.270 --> 00:03:29.820 you're going to get infinite ohms read on your display 101 00:03:29.820 --> 00:03:31.980 or an extremely high number. 102 00:03:31.980 --> 00:03:33.630 Anything that is not close to zero 103 00:03:33.630 --> 00:03:35.670 is going to be considered a broken wire 104 00:03:35.670 --> 00:03:37.470 and you should replace that faulty cable 105 00:03:37.470 --> 00:03:39.687 with a new one to solve your power issue. 106 00:03:39.687 --> 00:03:41.400 Now, the fourth issue we have, 107 00:03:41.400 --> 00:03:43.847 is when the power supply itself is faulty. 108 00:03:43.847 --> 00:03:46.350 Now, remember, when you're dealing with a power supply, 109 00:03:46.350 --> 00:03:47.550 its entire function 110 00:03:47.550 --> 00:03:50.670 is to take high voltage AC, or alternating current, 111 00:03:50.670 --> 00:03:52.530 as its input from your wall outlet, 112 00:03:52.530 --> 00:03:53.460 and then convert that 113 00:03:53.460 --> 00:03:56.070 into low voltage DC, or direct current, 114 00:03:56.070 --> 00:03:58.590 for use by the various components in your computer. 115 00:03:58.590 --> 00:04:01.860 Your power supply needs to provide three levels of voltage. 116 00:04:01.860 --> 00:04:06.860 This includes 12 volts DC, five volts DC, and 3.3 volts DC. 117 00:04:07.269 --> 00:04:08.550 If your power supply 118 00:04:08.550 --> 00:04:11.790 is not providing those three voltages at a stable level, 119 00:04:11.790 --> 00:04:14.070 that means your power supply is faulty. 120 00:04:14.070 --> 00:04:15.540 Now, when it comes to power supplies, 121 00:04:15.540 --> 00:04:17.610 you should never attempt to open them up 122 00:04:17.610 --> 00:04:19.380 and work on the inside of them. 123 00:04:19.380 --> 00:04:20.213 This is because 124 00:04:20.213 --> 00:04:21.870 there's a lot of high voltage components in there, 125 00:04:21.870 --> 00:04:23.160 including capacitors, 126 00:04:23.160 --> 00:04:24.780 that could provide an electric shock to you 127 00:04:24.780 --> 00:04:27.930 and either hurt you or kill you, in severe cases. 128 00:04:27.930 --> 00:04:29.760 So when you have identified 129 00:04:29.760 --> 00:04:31.320 that the power supply is the problem, 130 00:04:31.320 --> 00:04:34.110 you will simply take it out and replace it with a new one. 131 00:04:34.110 --> 00:04:35.618 In order to test your power supply, 132 00:04:35.618 --> 00:04:38.430 you can use a power supply tester. 133 00:04:38.430 --> 00:04:41.007 Now, a power supply tester is a small handheld unit 134 00:04:41.007 --> 00:04:43.818 that allows you to connect the output from the power supply 135 00:04:43.818 --> 00:04:45.510 using its different cables 136 00:04:45.510 --> 00:04:47.160 and be able to test the amount of voltages 137 00:04:47.160 --> 00:04:49.140 being received over those cables. 138 00:04:49.140 --> 00:04:50.670 For example, if you take 139 00:04:50.670 --> 00:04:52.770 the 20+4 pin motherboard connector, 140 00:04:52.770 --> 00:04:54.690 or 24 pin motherboard connector 141 00:04:54.690 --> 00:04:56.160 depending on your power supply, 142 00:04:56.160 --> 00:04:58.470 and connect it into this power supply tester, 143 00:04:58.470 --> 00:05:00.930 you should see that you have around 12 volts DC, 144 00:05:00.930 --> 00:05:04.230 five volts DC, and 3.3 volts DC. 145 00:05:04.230 --> 00:05:08.010 Now, you don't necessarily have to have exactly 12.0 volts, 146 00:05:08.010 --> 00:05:10.770 or 5.0 volts, or 3.3 volts 147 00:05:10.770 --> 00:05:12.840 for that power supply to be considered good. 148 00:05:12.840 --> 00:05:15.690 There is a small variation or tolerance to this. 149 00:05:15.690 --> 00:05:18.360 But, essentially, it should be very close to those numbers. 150 00:05:18.360 --> 00:05:22.380 So for example, if you have 11.9 or 12.1, 151 00:05:22.380 --> 00:05:24.390 that is considered 12 volts DC 152 00:05:24.390 --> 00:05:26.400 for the purposes of a power supply tester 153 00:05:26.400 --> 00:05:28.650 and saying you have a good power supply. 154 00:05:28.650 --> 00:05:30.300 On the other hand, if you come back with something 155 00:05:30.300 --> 00:05:33.420 like, seven volts DC or nine volts DC, 156 00:05:33.420 --> 00:05:36.106 this is much lower than the 12 volts DC you're expecting 157 00:05:36.106 --> 00:05:38.605 and your computer will not operate properly. 158 00:05:38.605 --> 00:05:40.470 So make sure you keep this in mind 159 00:05:40.470 --> 00:05:42.780 when you're using a power supply tester. 160 00:05:42.780 --> 00:05:44.277 Generally, a power supply tester 161 00:05:44.277 --> 00:05:47.370 will have connections on both sides of the tester. 162 00:05:47.370 --> 00:05:49.860 Normally, the one on the bottom is the largest connector 163 00:05:49.860 --> 00:05:52.260 and that's going to be able to connect your motherboard power. 164 00:05:52.260 --> 00:05:55.655 On the top, you'll have four, six, and eight pin connectors, 165 00:05:55.655 --> 00:05:59.100 as well as SATA power connectors and Molex connectors 166 00:05:59.100 --> 00:06:00.815 in order for you to test all the variations 167 00:06:00.815 --> 00:06:02.490 of different power components 168 00:06:02.490 --> 00:06:03.810 that are coming from your power supply 169 00:06:03.810 --> 00:06:05.834 to ensure you have the right low voltage DC 170 00:06:05.834 --> 00:06:08.512 that's being provided by that power supply. 171 00:06:08.512 --> 00:06:10.650 Now, the fifth cause of a power issue 172 00:06:10.650 --> 00:06:11.720 could be that the power cables 173 00:06:11.720 --> 00:06:13.620 is going from the power supply unit 174 00:06:13.620 --> 00:06:15.445 to your different components, is faulty. 175 00:06:15.445 --> 00:06:17.460 Now, if you have a power supply unit 176 00:06:17.460 --> 00:06:19.560 that has cables that are able to be detached, 177 00:06:19.560 --> 00:06:21.674 you can actually test each of those individual cables, 178 00:06:21.674 --> 00:06:23.910 just like we did the power supply cable 179 00:06:23.910 --> 00:06:26.430 going from the wall outlet to the power supply. 180 00:06:26.430 --> 00:06:28.410 You're going to be able to do this using a multimeter 181 00:06:28.410 --> 00:06:30.870 by measuring the resistance across that cable. 182 00:06:30.870 --> 00:06:33.540 Again, you want a very low resistance level, 183 00:06:33.540 --> 00:06:37.320 somewhere around zero ohms or slightly above that. 184 00:06:37.320 --> 00:06:39.300 If you get a very high resistance level, 185 00:06:39.300 --> 00:06:41.550 this means there's a break in that cable. 186 00:06:41.550 --> 00:06:43.754 Now, when you're testing each of the detachable cables, 187 00:06:43.754 --> 00:06:47.040 you will have to check each pin on each side of the cable 188 00:06:47.040 --> 00:06:49.200 to verify you have full continuity. 189 00:06:49.200 --> 00:06:50.033 Now, for example, 190 00:06:50.033 --> 00:06:53.160 if you're using an eight pin CPU cable that's detachable, 191 00:06:53.160 --> 00:06:55.354 you're going to have to test eight individual wires 192 00:06:55.354 --> 00:06:57.960 based on the pin outs of that entire cable 193 00:06:57.960 --> 00:07:00.330 to verify that the entire cable is good. 194 00:07:00.330 --> 00:07:02.070 If even a single one of those eight pins 195 00:07:02.070 --> 00:07:04.170 or eight wires inside of the cable is bad, 196 00:07:04.170 --> 00:07:06.600 you're going to have to replace the entire cable. 197 00:07:06.600 --> 00:07:08.370 Now, the sixth and final power issue 198 00:07:08.370 --> 00:07:09.552 you might come across in the field, 199 00:07:09.552 --> 00:07:11.575 is when you have an incorrect voltage setting 200 00:07:11.575 --> 00:07:14.130 on that power supply unit itself. 201 00:07:14.130 --> 00:07:16.140 Now, this isn't very common in newer systems, 202 00:07:16.140 --> 00:07:17.814 because most newer power supply units 203 00:07:17.814 --> 00:07:19.757 do have auto-sensing voltage 204 00:07:19.757 --> 00:07:21.990 and there is no actual physical setting 205 00:07:21.990 --> 00:07:23.610 on that power supply unit. 206 00:07:23.610 --> 00:07:26.160 But in older power supplies and older servers, 207 00:07:26.160 --> 00:07:28.380 you may still come across this voltage setting 208 00:07:28.380 --> 00:07:30.330 on the back of the power supply unit. 209 00:07:30.330 --> 00:07:32.167 When you look at the back of the power supply unit, 210 00:07:32.167 --> 00:07:34.950 there will be a small switch that will allow you to set 211 00:07:34.950 --> 00:07:39.950 either 110 to 120 volts AC or 230 to 240 volts AC. 212 00:07:41.255 --> 00:07:46.255 Most commonly, this is going to be written as 115V or 230V. 213 00:07:46.980 --> 00:07:49.440 If you have the incorrect setting on the power supply unit 214 00:07:49.440 --> 00:07:50.880 and you plug it into a wall outlet 215 00:07:50.880 --> 00:07:52.980 that's providing the incorrect type of power, 216 00:07:52.980 --> 00:07:54.360 this can actually cause damage 217 00:07:54.360 --> 00:07:56.790 to the computer or the power supply unit, 218 00:07:56.790 --> 00:07:59.010 or it will just cause nothing to happen, 219 00:07:59.010 --> 00:08:00.840 because there's not enough power. 220 00:08:00.840 --> 00:08:03.210 For example, if you are in the United States 221 00:08:03.210 --> 00:08:06.000 and you're using 110 to 120 volts AC 222 00:08:06.000 --> 00:08:08.130 as your wall outlet supplied power, 223 00:08:08.130 --> 00:08:11.580 but your power supply unit is set to a 230 volts setting 224 00:08:11.580 --> 00:08:12.480 on the back of it, 225 00:08:12.480 --> 00:08:15.330 this will actually cause nothing to happen, 226 00:08:15.330 --> 00:08:18.480 because the power supply unit is expecting 230 volts 227 00:08:18.480 --> 00:08:21.780 and you're only providing 110 to 120 volts. 228 00:08:21.780 --> 00:08:24.360 So it's not enough power to turn on the computer 229 00:08:24.360 --> 00:08:25.920 and nothing will happen. 230 00:08:25.920 --> 00:08:27.240 Alternatively, though, 231 00:08:27.240 --> 00:08:28.974 if you take a computer from the United States 232 00:08:28.974 --> 00:08:31.797 set 110 to 120 volts AC, 233 00:08:31.797 --> 00:08:34.770 and you plug it into a 230 volt wall outlet 234 00:08:34.770 --> 00:08:35.826 in Europe or Asia, 235 00:08:35.826 --> 00:08:38.880 this will actually damage the power supply unit 236 00:08:38.880 --> 00:08:40.800 and it could cause a fire. 237 00:08:40.800 --> 00:08:43.200 This is a really dangerous thing, so it's important 238 00:08:43.200 --> 00:08:45.003 that you always check your power supply unit 239 00:08:45.003 --> 00:08:47.910 and determine if it has one of these voltage settings. 240 00:08:47.910 --> 00:08:49.140 If it does, make sure 241 00:08:49.140 --> 00:08:50.655 you're selecting the right voltage setting 242 00:08:50.655 --> 00:08:52.200 based on the area of the world 243 00:08:52.200 --> 00:08:53.910 that you're going to be operating this computer in 244 00:08:53.910 --> 00:08:56.833 and make sure it matches the wall outlets voltage output 245 00:08:56.833 --> 00:08:59.550 to ensure you're not going to damage the system. 246 00:08:59.550 --> 00:09:02.820 Now remember, there are six main causes of power issues. 247 00:09:02.820 --> 00:09:04.140 First, your power button 248 00:09:04.140 --> 00:09:06.570 might not be connected properly to the motherboard. 249 00:09:06.570 --> 00:09:08.130 Second, the wall outlet 250 00:09:08.130 --> 00:09:09.563 is not providing the right amount of voltage 251 00:09:09.563 --> 00:09:12.000 or the wall outlet is faulty. 252 00:09:12.000 --> 00:09:14.513 Third, the power cable to the computer is faulty. 253 00:09:14.513 --> 00:09:18.120 Fourth, the power supply unit itself is faulty. 254 00:09:18.120 --> 00:09:19.530 Fifth, the power cables 255 00:09:19.530 --> 00:09:22.020 from the power supply to the components is faulty. 256 00:09:22.020 --> 00:09:23.942 Or sixth, you have incorrect voltage 257 00:09:23.942 --> 00:09:26.280 being set on the power supply unit 258 00:09:26.280 --> 00:09:29.040 based on what your wall outlet is providing to you. 259 00:09:29.040 --> 00:09:30.390 Remember to keep all this in mind 260 00:09:30.390 --> 00:09:32.940 when your troubleshooting power issues on a system.