11:30: It might be worth mentioning that if you don't have any SMD resistors to repair something like this, and there's enough room in the enclosure, you can also just solder in some through-hole resistors. Just make them stand upright, and bend the legs to an L-shape so they have little feet that can go on the pad. If you want, you can secure and insulate by folding them over and putting some hot glue on them. I've done this a few times, and never had any problems with it. And THT resistors usually have better power ratings - if that's important.
Replacing the conformal coating on one or both sides of the board is a good idea, especially for something like a battery charger which gets exposed to moisture or high humidity. I have occasionally added it to battery chargers which have otherwise been damaged out in the field.
Digging a bit but maybe for the future: I think a Hilti battery should not be so hard to come by. Builders would usually have several and I'm sure you could also maybe rent one from a local hardware store. At least you can here in mainland Europe. Just as a thought for next repairs. Love the channel!
usually the charger needs a voltage from the battery to enable power out. This way it knows you aren't trying to charge a damaged cell. You can insert a small voltage source to trick it into starting up.
Hi, I have a similar if not the same. On my one, the fan engages when the battery is plugged in, otherwise it seems to be in standby mode. I'll take a reading from the unloaded output tomorrow and post it for you.
As the three 1 ohm resistors are burnt and seem to be too small a wattage for their use, why not fit the biggist you can get on the pads. This should make the fixed charger more reliable. When I wes designing or fixing pcb's, I usually did the above. Unfortunately designers/manufactures today design circuits to the bone, putting the lowest specificicatuon of wattage, voltage, etc. Especially a certain Asian country. Thanks for the great video. You make a good teacher as you explain what and why you are doing each repair.
I have an 18v makita duel battery charger , basically has 2 boards in it that are identical, one side works fine but in the other side it died, i found a shorted mosfet on the primary , replaced it and the charger works for 10 seconds or so and then shuts down and gives a battery error light . I cant for the life of me figure it out . Looking forward to the next video incase theres some information which can help me to mend this charger as its been bugging me ( spent hours and hours on it )
Basically you have about five options 1.Scrape away at the resistor and try to measure from one end to the centre of the 'carbon'. And them multiply the reading by two. 2. Find a Schematic 3. Ask on forums and RUclips channels etc to see if anybody has a good one to measure 4. If the cost of repair is worth it, try to find or buy a scrap one 5. As I did on this video, reverse engineer that part of the circuit and work out what the value should be
Definitely don't use smaller 1-ohm resistors there. The original ones all went open-circuit and the likely reason is that they were overheating and undersized. I can't think of any other reasonable explanation.
Which part was confusing? I will try to help you. Make sure you watch part 1 first though, it is linked in the video description and explains how the circuit works. This is a followup to that video
@@LearnElectronicsRepair it was for me at first glance .. aka terrible humor (hilt .. Hilti). I just had to wait and watch you peel back the onion. .. and yes I watched part 1 .. and most all your videos. Great work Richard.
11:30: It might be worth mentioning that if you don't have any SMD resistors to repair something like this, and there's enough room in the enclosure, you can also just solder in some through-hole resistors. Just make them stand upright, and bend the legs to an L-shape so they have little feet that can go on the pad. If you want, you can secure and insulate by folding them over and putting some hot glue on them. I've done this a few times, and never had any problems with it. And THT resistors usually have better power ratings - if that's important.
Replacing the conformal coating on one or both sides of the board is a good idea, especially for something like a battery charger which gets exposed to moisture or high humidity. I have occasionally added it to battery chargers which have otherwise been damaged out in the field.
Agreed
Good work Richard 👍👍👍
Digging a bit but maybe for the future: I think a Hilti battery should not be so hard to come by. Builders would usually have several and I'm sure you could also maybe rent one from a local hardware store. At least you can here in mainland Europe. Just as a thought for next repairs. Love the channel!
usually the charger needs a voltage from the battery to enable power out.
This way it knows you aren't trying to charge a damaged cell.
You can insert a small voltage source to trick it into starting up.
Heya, looks like a nice repair. so we have to wait for the battery to be sure. nice
Hi, I have a similar if not the same. On my one, the fan engages when the battery is plugged in, otherwise it seems to be in standby mode. I'll take a reading from the unloaded output tomorrow and post it for you.
Hi, unloaded I don't see any voltage on the contacts, maybe one of the other pins is a current sense as there is 1.5v between some of the pins.
Hey! Great job!
Would like to see a battery on the charger!
Hopefully we can make that happen.
Yeah I hope to get a battery from the local customer
As the three 1 ohm resistors are burnt and seem to be too small a wattage for their use, why not fit the biggist you can get on the pads. This should make the fixed charger more reliable.
When I wes designing or fixing pcb's, I usually did the above.
Unfortunately designers/manufactures today design circuits to the bone, putting the lowest specificicatuon of wattage, voltage, etc.
Especially a certain Asian country.
Thanks for the great video. You make a good teacher as you explain what and why you are doing each repair.
The battery must be part of the circuit.
I have some but I’m in Yorkshire ;)
I have an 18v makita duel battery charger , basically has 2 boards in it that are identical, one side works fine but in the other side it died, i found a shorted mosfet on the primary , replaced it and the charger works for 10 seconds or so and then shuts down and gives a battery error light . I cant for the life of me figure it out . Looking forward to the next video incase theres some information which can help me to mend this charger as its been bugging me ( spent hours and hours on it )
Try replace the optocouplers.
how we can figure the value of burn smd resistor some time the resistor code is damaged.
Basically you have about five options
1.Scrape away at the resistor and try to measure from one end to the centre of the 'carbon'. And them multiply the reading by two.
2. Find a Schematic
3. Ask on forums and RUclips channels etc to see if anybody has a good one to measure
4. If the cost of repair is worth it, try to find or buy a scrap one
5. As I did on this video, reverse engineer that part of the circuit and work out what the value should be
Don't think airlines will let you bring a big li-ion battery on board!
Definitely don't use smaller 1-ohm resistors there. The original ones all went open-circuit and the likely reason is that they were overheating and undersized. I can't think of any other reasonable explanation.
Putting a battery in a checked baggage isn’t allowed because of the risk of fire.
Confusing/challenging to the “hilt”.
Which part was confusing? I will try to help you. Make sure you watch part 1 first though, it is linked in the video description and explains how the circuit works. This is a followup to that video
@@LearnElectronicsRepair it was for me at first glance .. aka terrible humor (hilt .. Hilti). I just had to wait and watch you peel back the onion.
.. and yes I watched part 1 .. and most all your videos. Great work Richard.