 Hello, in the previous video I showed you the effects that this defective USB cable can have. For example, when you use it to power a device like the Portapac, the Portapac started to malfunction because of this defective cable. Here we are going to measure this cable using a USB measuring device that can measure voltage and current and then make calculations for resistance and power, a power bank and here an electronic load so that I can draw a constant current. I set it in to draw a constant current here, 250mA and that is important, that constant current. You can probably see the LED flicker here but that is an effect of my camera as I look at it directly, it is not flickering for me. So let's plug this in directly and turn on the load. And here you can see we have about 5 volts and 250mA that is being drawn and here we measure 5.14 volts at the power bank and 245mA. So what I need to do next here so we have this measurement is push this button so that we switch to line measurement and then we remove the device and put the cable between the device and the power bank so that the cable is being measured like this. And now you can see here quite the difference. We have 5.14 volts without the cable and 4 volts with the cable and the current drawn is about a constant 245 that's the same. So that's a huge difference we have more than a volt of drop on this cable just with 250mA. So let's push the next button to have the calculation and then you can see here that this cable has a resistance of 4.693 ohms and so that's a lot for a USB cable like this. So this is calculated so we have a difference of 1 volt and we are drawing 250mA. 1 volt divided by 0.25 amps that gives us around 4 ohms and here it's a bit more the difference is 1.14 so that explains the 4.63. Let's do the same with a good USB cable. So here I have another USB cable which is electrically fine mechanically it is not there is a bent in it so this might later on develop into an electrical problem but for the moment it is fine. So we start this again so 5.14, 245 push the button, remove the device, put in the cable in between and as you can see the voltage drop is way lower it's from 5.14 to 5.09. So that's a much lower voltage drop and that is explained by a much lower resistance. So let's make the calculation and here you can see the resistance is 0.2 ohms so that's normal for such a small cable like this while this cable here it has 4 ohms. I don't have the breakout connectors to measure this directly with a multimeter I will buy these breakout connectors so that I can do that measurement too but that is the difference and explains why this cable cannot deliver that much power to a device because of the resistance causing that voltage drop.