Hacked broken Dyson vacuum cleaner charger to see if it was repairable. Traced out circuit to find possible faults and tried to repair it. Uses tny278 switch mode power supply controller. It has a dual output of 25V6 and 18V6.
Sir, thanks to you my CHARGER IS WORKING. I found the short on the diodes, replaced it with two 1A in parallel and when I plug it in I could already here the transformer noise! I was so happy when the lite turned green while charging. I'm currently charging the batteries. I'm so grateful that people like you are out there, sharing knowledge. Many thanks from Italy!
Thanks for the great teardown. Some of the chargers only have one of the voltages so they will not work with all the units. I think the dual voltage units are due to a crossover in production during a change in charging voltage from Ni-Cd to Li-Ion technology. The diode from the 18V to 25V rail is probably there to share the reverse connected over voltage protection Zenner diode on the 25V rail.
What a great piece of detective work and reverse engineering. Changed a faulty diode and the charge light came on, but off after a couple of minutes. It’s blown the same diode again so there’s more wrong but it was worth trying. Thank you for sharing.
Thanks TH for delving into this charger. My Dyson DC31 appears dead. Motor wont run even when 22 volts is applied as you did in one of your tests. The DC 31 doesn’t have a mechanical microswitch. I suspect it gets a signal to the battery management system from the switch circuit somehow. And I suspect that the charger took out the Battery management system when it blew up. My batteries actually read 22 volts. I ripped open the charger and the 24 V Schottky is shorted same as yours and you may be interested to know that the IC marked IC101 has been blown apart. So, I just need a new battery and new charger to find out if the motor is okay. I don’t think I will take the gamble.
Thank you very much Sir, it is truly interesting to trace the whole board and drawing the diagram out. I was hoping for a easy fix but I probably just gonna buy a new one. Again, thank you for this video.
Opamp 1 is over voltage protection (the three pairs of resistors to the left of the 431 volt ref are summing the two 25v & 18v into one voltage, to be compared to the 431 voltage by opamp 1). Opamp 2 is over current protection (the voltage across the three current shunt resistors in parallel labelled 206 206 207 is compared to a reference voltage by opamp 2). So the output of either opamp will go low (and causes the power supply to shut down using the EN pin) if either output voltage gets too high or if too much current is drawn. I’m not 100% sure, someone please explain if I am wrong…
@@toyhacker4647 ok no worries 15:40 talking about op amp 1, 17:40 talking about op amp 2. Resistor 203 at 17:25 is needed for the volt ref to work, I believe. Without it the volt ref will effectively only be connected to the 0v rail and won’t be able to produce it’s 2.495v. 13:20, it looks like op amp 4 is a non inverting amplifier to amplify the voltage across the current shunt… op amp 3 is a comparator that turns the charging LED off if the current draw drops below some preset level, adjustable using ‘VR 201’.
hello, i have the problem that i haven't got 2 resistance smd in my charger, could you say me what is the number resistance of the smd 213 and 213a?? thank you for the video and is awesome!
Good job I have one of these Dysos. Was ok 6-7 months. On warranty I got a new charger. Now again shutdown and I never buy this product again. Why do they design it this way??? It's not rocket science to make a decent charger much simpler and better way. But that's the way they make money.
True but that's the way the world works. It keeps people in work so they can buy stuff so we don't get a depression like the US in the 1930's when stuff was built to last so the factories and then every thing else shut down. I've expected the whole system to collapse for years but luckily it still keeps going.
@@toyhacker4647 Thx for the video, but I've come to the same conclusion as you. I've ordered a new one, but at least I have tried to reduce waste. I tought that just a capacitor was broke.
Don't use anything but an intelligent charger. The vac uses lithium cells which must be charged with an intelligent charger, hence all the electronics in the Dyson charger. Videos show lithium batteries bursting into flames and I believe they have been the cause of aircraft being grounded and phones recalled.
A high quality current limited charger is likely to work, the current limiting may be a charge current limiting feature. As far as I know the Dyson units ONLY use one of the voltages. I think it may be a legacy to support different number of cells in the battery. Some of the Dyson chargers only have one output voltage.
