1 00:00:07,110 --> 00:00:09,240 - [Instructor] Clean, well-planned power 2 00:00:09,240 --> 00:00:12,030 is vital for a computer system. 3 00:00:12,030 --> 00:00:15,930 As far as the typical A-plus technician is concerned, 4 00:00:15,930 --> 00:00:19,770 power starts at your building's electrical panel 5 00:00:19,770 --> 00:00:24,210 and continues on through to the AC outlet, 6 00:00:24,210 --> 00:00:25,833 power protection equipment, 7 00:00:26,670 --> 00:00:29,250 and then the PC with the power supply, 8 00:00:29,250 --> 00:00:32,520 and then internally with the DC power connections 9 00:00:32,520 --> 00:00:33,993 inside that PC. 10 00:00:35,130 --> 00:00:37,590 Now, the A-plus exam is most concerned 11 00:00:37,590 --> 00:00:42,300 with the power supply and the internal power connections. 12 00:00:42,300 --> 00:00:46,500 Generally, a 500-watt power supply, 13 00:00:46,500 --> 00:00:48,000 like the one shown here, 14 00:00:48,000 --> 00:00:51,000 is enough for basic systems. 15 00:00:51,000 --> 00:00:54,180 But not if you're doing some powerful computing. 16 00:00:54,180 --> 00:00:58,803 Then, you might need 600 watts or 750 watts 17 00:01:00,270 --> 00:01:04,260 or even 1000 watts or even more. 18 00:01:04,260 --> 00:01:08,580 Underpowered systems can lead to all kinds of failures, 19 00:01:08,580 --> 00:01:12,360 intermittent failures or permanent failures. 20 00:01:12,360 --> 00:01:15,450 The power supply must meet the requirements of your computer 21 00:01:15,450 --> 00:01:16,323 and then some. 22 00:01:17,190 --> 00:01:20,370 A good engineer always over-plans 23 00:01:20,370 --> 00:01:22,380 at least a little bit, right? 24 00:01:22,380 --> 00:01:25,110 So power planning should be right up there 25 00:01:25,110 --> 00:01:29,520 with the choice of CPU, RAM, and motherboard. 26 00:01:29,520 --> 00:01:31,083 It's all intertwined. 27 00:01:32,370 --> 00:01:36,090 Most of the time, I will refer to the power supply unit 28 00:01:36,090 --> 00:01:39,687 as either power supply or PSU, 29 00:01:39,687 --> 00:01:43,080 and PSU stands for power supply unit. 30 00:01:43,080 --> 00:01:46,803 And CompTIA will sometimes use that acronym as well. 31 00:01:47,700 --> 00:01:50,610 Now, the power supply unit in a PC 32 00:01:50,610 --> 00:01:55,610 is in charge of converting alternating current, or AC, 33 00:01:56,340 --> 00:01:59,850 which is drawn from the wall outlets, 34 00:01:59,850 --> 00:02:04,850 into direct current to be used by the computer, 35 00:02:05,460 --> 00:02:09,630 and that direct current's gonna come out of all these ports. 36 00:02:09,630 --> 00:02:11,700 The PSU, the power supply unit, 37 00:02:11,700 --> 00:02:15,423 then feeds the devices in the computer. 38 00:02:16,620 --> 00:02:21,150 For example, the 24-pin connection to the motherboard, 39 00:02:21,150 --> 00:02:26,137 a six or eight-pin PCI express power connection to the GPU, 40 00:02:27,407 --> 00:02:29,130 SATA connections, 41 00:02:29,130 --> 00:02:31,560 15-pin SATA power connections 42 00:02:31,560 --> 00:02:33,573 to the hard drives and optical drives. 43 00:02:35,610 --> 00:02:40,200 You've also got the CPU fan and other case fans, 44 00:02:40,200 --> 00:02:45,200 and also the eight or four-pin CPE connection for power 45 00:02:46,530 --> 00:02:47,880 as well. 46 00:02:47,880 --> 00:02:50,340 So the power supply unit feeds everything 47 00:02:50,340 --> 00:02:51,603 inside that system. 48 00:02:52,530 --> 00:02:56,250 Use a certified and reliable brand. 49 00:02:56,250 --> 00:02:58,170 Make sure that the power supply unit 50 00:02:58,170 --> 00:03:01,830 meets the standards that are set by organizations 51 00:03:01,830 --> 00:03:06,830 such as the IEC or the FCC or UL and so on. 52 00:03:07,650 --> 00:03:12,650 And also that it meets the ROHS Directive, R-O-H-S, 53 00:03:12,720 --> 00:03:15,480 for things like lead and mercury. 54 00:03:15,480 --> 00:03:18,090 So you wanna remember to plan accordingly. 55 00:03:18,090 --> 00:03:22,260 You should know the type of power supply you need, 56 00:03:22,260 --> 00:03:25,050 for example, ATX most of the time, 57 00:03:25,050 --> 00:03:27,480 and the compatibility of that power supply 58 00:03:27,480 --> 00:03:29,400 with the rest of your system. 59 00:03:29,400 --> 00:03:33,390 You also wanna know the wattage and capacity requirements, 60 00:03:33,390 --> 00:03:35,310 and you can use a power calculator for that, 61 00:03:35,310 --> 00:03:37,590 and I'll show that in another video. 62 00:03:37,590 --> 00:03:41,160 You also wanna know the number and type of connectors 63 00:03:41,160 --> 00:03:42,333 that you'll be using. 64 00:03:43,710 --> 00:03:47,820 So remember the power supply unit, or PSU, 65 00:03:47,820 --> 00:03:50,850 converts AC to DC, 66 00:03:50,850 --> 00:03:52,260 and it feeds that direct current 67 00:03:52,260 --> 00:03:54,603 to all the stuff inside the computer. 68 00:03:55,920 --> 00:03:59,490 Now, let's look here, on a typical power supply unit, 69 00:03:59,490 --> 00:04:01,383 at the different parts here. 70 00:04:02,460 --> 00:04:05,130 Okay, here we have the back, 71 00:04:05,130 --> 00:04:07,200 and what we're looking at here... 72 00:04:07,200 --> 00:04:08,910 We have a port. 73 00:04:08,910 --> 00:04:13,910 That is the C14 inlets for the IEC power cable, 74 00:04:15,750 --> 00:04:20,750 which is defined in the IEC 6320 spec, right? 75 00:04:21,480 --> 00:04:26,320 And so the cable itself connects to this 76 00:04:27,600 --> 00:04:30,360 with a C13 line socket. 77 00:04:30,360 --> 00:04:33,420 And on the other end, it goes out to the AC outlet 78 00:04:33,420 --> 00:04:35,400 with a three-prong connector. 79 00:04:35,400 --> 00:04:38,910 Here, we have a shutoff switch, also known as a kill switch. 80 00:04:38,910 --> 00:04:43,740 If you turn that off, then no power will come to this. 81 00:04:43,740 --> 00:04:45,480 It'll block this altogether. 82 00:04:45,480 --> 00:04:49,290 But it's still a good idea to unplug the computer 83 00:04:49,290 --> 00:04:51,183 before you do any types of work. 84 00:04:52,200 --> 00:04:56,070 And over here, we also have a voltage selector. 85 00:04:56,070 --> 00:04:57,480 And right now it's upside down, 86 00:04:57,480 --> 00:04:59,520 but this is set to 115, 87 00:04:59,520 --> 00:05:02,910 which also is the same as 120 volts AC. 88 00:05:02,910 --> 00:05:06,780 In other countries, you may have to select 230. 89 00:05:06,780 --> 00:05:08,190 So what this indicates to us 90 00:05:08,190 --> 00:05:11,310 is that this is a dual voltage power supply. 91 00:05:11,310 --> 00:05:14,610 Again, should be set at 115 volt in the United States 92 00:05:14,610 --> 00:05:15,900 and some other countries, 93 00:05:15,900 --> 00:05:18,480 but it has that 230 volt for other countries, 94 00:05:18,480 --> 00:05:21,360 and an additional adapter might be necessary 95 00:05:21,360 --> 00:05:24,390 for the different wall outlets that you might encounter. 96 00:05:24,390 --> 00:05:26,490 Never change the voltage selector switch 97 00:05:26,490 --> 00:05:29,550 while the computer is running or plugged in, 98 00:05:29,550 --> 00:05:31,470 and be sure to check this setting 99 00:05:31,470 --> 00:05:34,143 before you initially use the power supply. 100 00:05:35,070 --> 00:05:37,290 Now, back in the day, all of the cables 101 00:05:37,290 --> 00:05:40,500 came directly out of the power supply unit, 102 00:05:40,500 --> 00:05:42,930 and you had little control. 103 00:05:42,930 --> 00:05:47,250 More and more though, today, power supplies are modular, 104 00:05:47,250 --> 00:05:50,190 meaning that you connect the power cables 105 00:05:50,190 --> 00:05:52,800 into the power supply 106 00:05:52,800 --> 00:05:54,750 as well as into the other side, 107 00:05:54,750 --> 00:05:58,350 with the motherboard, the CPU, and everything else. 108 00:05:58,350 --> 00:05:59,250 So on the left here, 109 00:05:59,250 --> 00:06:03,390 we have a fully modular power supply unit, 110 00:06:03,390 --> 00:06:05,370 and all these connections, the cables, 111 00:06:05,370 --> 00:06:06,963 plug directly into that. 112 00:06:07,890 --> 00:06:11,220 On the right here, we have a partially modular connection. 113 00:06:11,220 --> 00:06:16,220 And so we have PCI express ports here for our video cards. 114 00:06:16,530 --> 00:06:20,340 Then, we have our Molex connectors, 115 00:06:20,340 --> 00:06:22,410 also known as peripheral, 116 00:06:22,410 --> 00:06:25,323 for our hard drives, SATA, and so on. 117 00:06:26,190 --> 00:06:28,470 And that's just on this end. 118 00:06:28,470 --> 00:06:31,470 On the other end, it'll look like an SATA connection 119 00:06:31,470 --> 00:06:33,000 if you have the right cables. 120 00:06:33,000 --> 00:06:36,180 But then you also have actual cables coming out of there. 121 00:06:36,180 --> 00:06:38,460 So you have multiple options with that one. 122 00:06:38,460 --> 00:06:40,200 That's a partially modular, 123 00:06:40,200 --> 00:06:42,363 as opposed to this, which is fully modular. 124 00:06:43,530 --> 00:06:46,200 Okay, so know the difference between those. 125 00:06:46,200 --> 00:06:48,600 And let's go ahead and show 126 00:06:48,600 --> 00:06:51,873 an actual power supply now and its connections. 127 00:06:52,830 --> 00:06:55,710 Okay, let's talk about power connector types. 128 00:06:55,710 --> 00:06:59,220 Here, we have a standard ATX power supply, 129 00:06:59,220 --> 00:07:01,950 and this is what we're gonna install to our computer. 130 00:07:01,950 --> 00:07:02,783 And you can see, 131 00:07:02,783 --> 00:07:06,030 we have some cables coming out and some ports here. 132 00:07:06,030 --> 00:07:08,130 Now, the main power connector 133 00:07:08,130 --> 00:07:12,810 that you'll use to supply power to the motherboard 134 00:07:12,810 --> 00:07:14,070 is this guy here, 135 00:07:14,070 --> 00:07:16,863 and this is a 24-pin connector. 136 00:07:18,000 --> 00:07:18,960 Back in the day, 137 00:07:18,960 --> 00:07:22,230 these used to be known as 20-pin connectors, 138 00:07:22,230 --> 00:07:24,480 and known as the P1 connector. 139 00:07:24,480 --> 00:07:27,630 And it, in fact, still has the name P1 on there, 140 00:07:27,630 --> 00:07:29,730 but they added four pins after a while, 141 00:07:29,730 --> 00:07:33,870 and that's the standard now, a 24-pin ATX connector. 142 00:07:33,870 --> 00:07:36,030 So that's gonna connect directly to the motherboard, 143 00:07:36,030 --> 00:07:40,140 and this supplies positive five, positive 12, 144 00:07:40,140 --> 00:07:44,910 positive 3.3, negative five, and negative 12 voltages. 145 00:07:44,910 --> 00:07:48,240 Plus, you have the black ground wires. 146 00:07:48,240 --> 00:07:52,080 So this is your main power connector to the motherboard. 147 00:07:52,080 --> 00:07:55,740 And we'll connect that in one of the following sub lessons. 148 00:07:55,740 --> 00:07:57,990 Another one of the connectors we see here... 149 00:07:57,990 --> 00:07:58,983 We have a couple. 150 00:07:59,940 --> 00:08:04,940 The first is the connectors for additional CPU power. 151 00:08:05,400 --> 00:08:09,990 These are each four-pin connectors, and there's two of 'em. 152 00:08:09,990 --> 00:08:13,173 And so these are labeled as P3. 153 00:08:14,310 --> 00:08:18,990 And you can see that you got two four-pin connectors here. 154 00:08:18,990 --> 00:08:21,090 So those are gonna connect to the motherboard as well 155 00:08:21,090 --> 00:08:22,833 for additional CPU power. 156 00:08:24,480 --> 00:08:28,680 And finally, we have another cable here, 157 00:08:28,680 --> 00:08:31,920 and this is for your PCI express video cards, 158 00:08:31,920 --> 00:08:34,470 and it's a six-pin connector. 159 00:08:34,470 --> 00:08:36,300 And then you have an additional two pins 160 00:08:36,300 --> 00:08:39,960 in case you have an eight-pin connector on the video card. 161 00:08:39,960 --> 00:08:44,220 And you can see here, it says PCI-E, PCI express. 162 00:08:44,220 --> 00:08:46,620 So we're not actually gonna use this 163 00:08:46,620 --> 00:08:49,140 on the video card that we have on the computer 164 00:08:49,140 --> 00:08:50,910 because it doesn't need any additional power. 165 00:08:50,910 --> 00:08:52,410 It gets power from the motherboard. 166 00:08:52,410 --> 00:08:54,720 But I most likely will upgrade 167 00:08:54,720 --> 00:08:56,610 and will need a six-pin connector, 168 00:08:56,610 --> 00:08:59,043 possibly an eight-pin connector. 169 00:09:00,930 --> 00:09:04,050 Now, if we look here, we see we have additional ports, 170 00:09:04,050 --> 00:09:07,680 and this is where we connect our additional power connectors 171 00:09:07,680 --> 00:09:11,220 for things like secondary video cards. 172 00:09:11,220 --> 00:09:14,137 For example, here, you can see it says 173 00:09:14,137 --> 00:09:17,310 "12-volt PCI express hard drives." 174 00:09:17,310 --> 00:09:21,090 You can connect a power connector to this 175 00:09:21,090 --> 00:09:26,090 for an additional PCI express video card or for hard drives. 176 00:09:26,400 --> 00:09:28,143 And they give you an extra cable, 177 00:09:29,160 --> 00:09:31,770 and you can see this one has a red connector, 178 00:09:31,770 --> 00:09:33,840 and so that's actually just gonna connect 179 00:09:33,840 --> 00:09:36,603 right to the power supply itself. 180 00:09:38,880 --> 00:09:41,490 And it snaps in with the little tab here 181 00:09:41,490 --> 00:09:43,200 that locks it in place. 182 00:09:43,200 --> 00:09:44,493 And then the other end, 183 00:09:45,360 --> 00:09:50,360 this would go to the PCI express port on the video card. 184 00:09:51,480 --> 00:09:53,970 And then you have an additional four ports, 185 00:09:53,970 --> 00:09:56,073 and these are meant for hard drive only. 186 00:09:57,180 --> 00:10:00,120 And these also use the six-pin power connector, 187 00:10:00,120 --> 00:10:02,070 and they give you a cable... 188 00:10:02,070 --> 00:10:03,933 Actually, two cables for this. 189 00:10:05,730 --> 00:10:06,570 And you can see this. 190 00:10:06,570 --> 00:10:08,350 This is the six-pin power connector 191 00:10:09,270 --> 00:10:12,240 that would just connect right to one of these. 192 00:10:12,240 --> 00:10:14,373 And again, with the tab facing down. 193 00:10:17,280 --> 00:10:18,423 Snaps in place. 194 00:10:19,530 --> 00:10:21,750 But if you look further on this, 195 00:10:21,750 --> 00:10:25,830 you'll see there's three SATA power connectors, 196 00:10:25,830 --> 00:10:27,843 one, two, and three. 197 00:10:31,290 --> 00:10:36,290 And that's your standard 15-pin SATA power. 198 00:10:38,760 --> 00:10:41,190 And so if you have three drives or less, 199 00:10:41,190 --> 00:10:42,600 the one cable is enough, 200 00:10:42,600 --> 00:10:45,030 but generally they give you a second one. 201 00:10:45,030 --> 00:10:46,560 This way, you can add more drives, 202 00:10:46,560 --> 00:10:49,230 or if you want your drives to run 203 00:10:49,230 --> 00:10:51,630 on separate rails of power, 204 00:10:51,630 --> 00:10:54,030 you could have one connected to this cable 205 00:10:54,030 --> 00:10:57,210 and another one connected to the cable on here. 206 00:10:57,210 --> 00:10:58,620 And that's what's also good 207 00:10:58,620 --> 00:11:02,790 about the additional PCI express power connector. 208 00:11:02,790 --> 00:11:07,790 You could have your main PCI express, which comes from here, 209 00:11:10,920 --> 00:11:13,290 but then you could have a separate PCI express power 210 00:11:13,290 --> 00:11:15,870 for a second video card coming from here, 211 00:11:15,870 --> 00:11:18,570 and it would run on separate rails, which is good. 212 00:11:18,570 --> 00:11:20,970 This way, you don't overheat the system. 213 00:11:20,970 --> 00:11:23,010 And that's pretty much automatic. 214 00:11:23,010 --> 00:11:24,120 You don't have a choice about that. 215 00:11:24,120 --> 00:11:25,803 So that's a nice feature of this. 216 00:11:27,300 --> 00:11:29,310 Okay, let's look at the back ports here. 217 00:11:29,310 --> 00:11:33,390 There's just the one port, the C14 inlet, 218 00:11:33,390 --> 00:11:35,670 and that's gonna be for your main power cable. 219 00:11:35,670 --> 00:11:39,090 Quite often, we'll refer to this as an IEC power cable. 220 00:11:39,090 --> 00:11:42,600 And the power supply should come with a new IEC cable. 221 00:11:42,600 --> 00:11:46,020 Make sure you use the one that came with the power supply. 222 00:11:46,020 --> 00:11:49,950 And this is known as an auto-sensing power supply, 223 00:11:49,950 --> 00:11:53,280 which means that it will auto sense 224 00:11:53,280 --> 00:11:55,410 what voltage you're connecting to. 225 00:11:55,410 --> 00:12:00,137 In the US, this will be your your typical 120-volt outlet. 226 00:12:01,500 --> 00:12:03,990 In other countries, that'll be 240. 227 00:12:03,990 --> 00:12:07,470 And it might be labeled as 115/230. 228 00:12:07,470 --> 00:12:08,520 It depends. 229 00:12:08,520 --> 00:12:10,380 It might not be labeled at all. 230 00:12:10,380 --> 00:12:12,360 But ones like this are auto-sensing. 231 00:12:12,360 --> 00:12:15,840 Older power supplies would have a little red switch, 232 00:12:15,840 --> 00:12:18,090 as shown in the picture here. 233 00:12:18,090 --> 00:12:20,670 And that allows you to, you know, 234 00:12:20,670 --> 00:12:22,920 select which voltage you want. 235 00:12:22,920 --> 00:12:26,073 In addition, you see a hard on/off switch. 236 00:12:27,000 --> 00:12:30,150 It's just a rocker switch on/off. 237 00:12:30,150 --> 00:12:31,920 This allows you to kill the power. 238 00:12:31,920 --> 00:12:34,170 Sometimes it's referred to as a kill switch. 239 00:12:34,170 --> 00:12:36,450 But it allows you to kill the power 240 00:12:36,450 --> 00:12:39,300 without disconnecting the cable, 241 00:12:39,300 --> 00:12:40,620 which is a nice feature. 242 00:12:40,620 --> 00:12:42,750 And I always get that on my power supplies. 243 00:12:42,750 --> 00:12:44,460 If I'm ever doing any troubleshooting, 244 00:12:44,460 --> 00:12:47,550 I really don't feel like disconnecting the power itself. 245 00:12:47,550 --> 00:12:49,470 I just wanna turn it off here. 246 00:12:49,470 --> 00:12:50,303 And when you're done though, 247 00:12:50,303 --> 00:12:52,410 just make sure that you click it back on, 248 00:12:52,410 --> 00:12:54,270 so that it does work. 249 00:12:54,270 --> 00:12:55,980 And we have a fan on the bottom. 250 00:12:55,980 --> 00:13:00,980 That's gonna exhaust the hot air outta the case. 251 00:13:02,850 --> 00:13:04,590 And you wanna make sure you have that vent 252 00:13:04,590 --> 00:13:06,030 on the bottom of the case. 253 00:13:06,030 --> 00:13:08,100 Sometimes, those will have a filter as well. 254 00:13:08,100 --> 00:13:09,870 Our case has a filter. 255 00:13:09,870 --> 00:13:11,640 And you wanna clean that out once in a while 256 00:13:11,640 --> 00:13:13,110 if you work in a dusty environment. 257 00:13:13,110 --> 00:13:15,180 Really, in any environment. 258 00:13:15,180 --> 00:13:17,043 And so there's your power connectors.