14" EGO 56V Chainsaw Teardown and Repair

today on the bench I want to look at the ego 14-inch chain saw on a previous video I showed the 16 inch that I bought it performed very very well I come across this 14-8 shipped to me as he is the stator that was non-functional I didn't know if it was just missing pieces that it had been robbed off or truly truly non-functional after receiving it it was pretty obvious that it really is a major issue with the saw I was really looking forward to taking one apart and having a peek inside I really didn't want to take my new 16 inch apart but I bought this 14 inch it is the cs 1400 so I have taken all the screws out of the housing I'm actually gonna put this screw back into the handle so it won't come apart when I put the battery in but one thing we noticed right off its the battery indicator when I plug it in i noticed it should come on and show green at least on my saw it does so when you put this in and it doesn't show you the actual battery indicator the light don't come on so right off the bat I thought it might really be in the electronics so so the masala does not work at all so that's where I was that I was taking the cover off I have taken those screws out already how so now I have taken the screws out of the shroud that's just on there with a tie wrap so we get a good look at how the switch works it has a safety lock we have to push into the center of the handle and once we push that in we can make the switch we've set this aside we will need it for troubleshooting so I have a few switches here that I can actually rule out but once again since it didn't pick up the battery pack in place one thing that's going to as a speed control so get a good look at the brushless motor the switch for the brake as well as a very minimalistic mechanical stop to that but mainly I guess it goes across the switch for the brake like a resistive brake I'm assuming and probably custom motor power as well we're looking at some more but there is our apparently like the Hall effect feedback going to the speed controller and our three phases to the brushless motor we got the speed controller with them a little resistor Bank and also have a electrolytic capacitor 680 microfiber 63 volt it's not bulged or physically leaky looks like someone K ohm resistors maybe we'll start looking at this from over here there's no problem with the power switch [Music] okay so what we have here it looks like the blue and the yellow coming out of the speed control is going through the switch so we got our common two in the middle it should be and normally is switching to here so they'd yellow to yellow the blue to blue so normally it's just coming out of here it looks like we got a blue yellow and a brown the brown is going straight to one face then we got blue and yellow so typically when running and the brakes not hit with your arm or your safety brake isn't hit then you yell them blue go to the motor it's normal when it's hit and it switches then it's going to keep back and switch what was going to your motor or it's still going to your motor the center pole for your motor is going to switch and it's actually going to put them together and it's going to stop the motor like a brake apparently which we also look here we have some resistors coming off of the speed control I just want to check this switch really quick although I don't suspect that would stop what's going on with it so with the brake activated it should be going to the red so that's good blue is also good and then normal should be yellow to yellow and blue to blue yeah believe it a blue so that's good so no problem with the switch either one the switches so our initial thoughts are probably true it's gonna be something to speed control I don't know how well you can see the speed controller it does have a silicon clear potting material one thing that's very evident there's a a 40 amp fuse right here at the very top I can actually feel it with my finger through the through the potting so it should be easy enough to get through and get through and to and probe so it looks like this fuse may be below so we can dig a little deeper in this what I've started doing is just getting my little tool and going around the edge and trying to see if I can get some of this pot material out just want to be careful around any components I don't see nothing but a connector at the bottom that's actually the young the heat sink thermal compound you even though the first thing we come to looking to be an issue that's not overly optimistic um I've been working on stuff for a lot of years and usually when I big fuse is blown you usually find a reason for don't get me wrong sometimes you get lucky usually the exception rather than the rule so if you can see that on camera I just got a zero on reading across the battery connection where the power with the power switch pushed so therefore after jumping out the fuse before applying power I wanted to check and see if I had a dead short going into the speed control and as you can see obviously it is it is a dead short so definitely want to hook battery up to that it'll just damage something else I did notice on tracing these white wires coming out of the speed control seemingly going to negative if they are soldered together there it looks like they are we're going across negative across the top of resistors these are 1k resistors you verify that it looks like the color code oh there we go 1k what getting a good connection because I was saying earlier it looks like the negative coming from the battery terminal is going across these resistors and going across each other outputs of the phases for this brushless motor it looks like I'm gonna have to try to get this out it looks like they give me no choice but to try to bust the house and then get in there so here we go I try to be gentle at least I can see some MOSFETs in there now no doubt we had to get to the power side you so far that's what we have I definitely want to get under this heat sink under the heat sink has to be where your power devices are to put out the kind of wattage it takes to run this chainsaw there we go our heat transfer a little silicon pad still intact and I did not expect that but it is a lot of surface mount I'm assuming MOSFETs on that board one thing to note as I was jumping that fuse earlier just testing I mentioned you would never want to try to put it across without checking to make sure it wasn't shorted now if I did want to hook the battery up to something of this nature what I would always do would be jump the fuse in question especially when it's a large one like this but it'll work on anything you can go across the load like a light bulb that's rated for that voltage this is a standard 120 volt 60 watt light book or 40 watt light bulb so what's going to be around 10 ohms resistance across the development when you do this if you have a short your light just comes on and that's just a good trick any time you are trying to jump around a fuse something that you think might have a short-circuit instead of a jumper or another fuse that could just blow or pop and you're definitely never one just put a straight jump or across it unless you just troubleshooting like I was omen not applying power but in this case the 60 votes from our battery or 56 volts for my battery is actually coming across a dead short here so the difference in potential but the 56 votes ends up across where the fuse would be and it would have blew the fuse but instead it just lights or light bulbs so just always good to keep that in mind when oh shoot I have decided I'm going to go ahead and cut backs remote elites flush as I can off the board and so doing that they kind of separate it out I should be able to get this connector or loose from the motor connection board there we go that is a connector you can see that coming loose there okay it's real similar to the connectors on their battery BMS board on a previous video we repaired one of the ego 2.5 amp power batteries there's similar it ain't the same but a similar to some of those connectors and now we have this off I'll be back with a cleaned off bench and that's where we can look at a little better so now while troubleshooting I have clipped off the motor leads going through the three-phase brushless motor and you can see this screen here on this 179 meter I just have my K ohm resistance which the 1k is is that resistor going back to the negative terminal on the battery so that was showing 0 ohms and of course checking across the motor even after clipping them off the motor does show very low resistance is showing zero ohms which most windings on a motor that large will will show really low resistance so now want to check this it's not showing a short like I thought it was but that still doesn't mean this isn't bad if I jump out the few just for testing purposes and use this meter across the battery terminals plus and minus and activate the switch there goes I did short again so what is still something when these mice best it is shorter yeah definitely tell from for my negative to our positive definitely a dead short so with the first ship removed the shortened the ground actually went away I no longer had a my dad short from ground to that first face output and when I check across back for my spit it's tough that I took off it's definitely short of the cross the source and the drain so that one was definitely bad as they going to the the second MOSFET this turn switch in the same direction because if we noticed here we had to turn one direction and of course to turn the other so that's I switch and I positive and negative so now that's clear but I am still showing a short come out the positive that shouldn't be short of either so one of these two on this circuit coming off the positive it's also it's also shorted so I'm gonna have to take at least one of these off if not both to get that shortened of completely clear it's a lot of these and a lot of pad under these little chips for the high current capacity so it does take a little while down side are these little small chips so after cleaning the board up and checking across the paths of that second transistor removed a MOSFET removed I'm still short of the cross those paths which means this one here is also shorted I believe those pads are the same I think they're in parallel yeah so I think these two were in parallel and of course these two in parallel at the moment with this one removed this that's clear and although this one was shorted this they were calling this one transistor 38 it looks like this transistor 38 removed this Q 32 is gonna also be shorted so I have to also take it off so everything looks pretty good at the desoldering three out of the four MOSFETs everything is clear now so all three of those MOSFETs out of the four were shorted have 100 and that is the gate Philip had for the gate right here this path for the gate has went away so I'm going to have to do a little jumper wire from where the gate is to this 100 ohm resistor this r88 you can see yes what a pad was it went over so not a big issue but I hate that that pad left the door the one did fine to pick the pad stayed on it so that's one of the benefits of a hot air I just hot air actually hits the whole area so even on a surface area this big I would imagine even this little resistor will be gone so I try to pinpoint what the pin with the soldering iron taking the old ones off if I can I didn't seem to do too well on the little small pad I didn't have enough heat on it directly I was more concerned with putting the heat to the big pad to release it and then go back and make sure I put heat back again on this little isolated pad so one little fix there hopefully I won't be a big issue to take care of so now we have all four removed because I just want to put our four brand-new and my camera froze up when I install the MOSFETs I just want to my afford to be brand new so that's all forward moved with a new solder on the pads and also we have the 40mm use has been removed also so when I get my new MOSFETs in I'll be able to put them in place and run that small gate jumper the hair back into it to that 100 ohm resistor so I did get in the new power MOSFETs that is depending on the MOSFET package some of the ratings which is a very impressive up to 337 amps on these little things with a very limited rating there on the note 2 on the pulse drain current 337 it does say with pulse of equal to or less than 100 microseconds at a duty cycle of equal to or less than 1% but nonetheless it is rated for that we also have a continuous drain current of 16 amps and up to 110 amps on the actual drain current of course being a hundred volt rated a package - so very neat little package well my microscope camera actually wasn't recording the whole time with these two chips maybe to keep recording now we'll see it actually froze up on me move on to the third one these actually have to turn the other way like so I already have some solder in place put some more flux you just trying to add this jumper wire to the gate to the resistor well it appears my microscope is locked up again it looks like I need to get me a hot air station as well as a new camera which the camera still does a good job for me seeing it's just for some reason on the SD card is cheaper camera it just it's been doing it since it was new but it would lock up sometimes it's gotten really bad lately it's a it's something recorded 17 seconds and it's locked up mmm it won't power off or anything I have to hit the reset button on the back to get it back soon I wish I had it this way to start with a record and I'm gonna make sure that you can see the screen somewhat instead of trying to record with it now for those hands are together so that's actually okay even though it's not pretty that is okay these on the other hand you got your three source and then you've got your gate and the other four all drains so the main the main one is to make sure I gate with this real fine pitch device we just got to make sure we don't get anything short of over to that gate that would not be good so it looks like with a smaller tip now I do have a good connection on the pins on the bottom of that um that's actually the drain on this transistor I'm just going to go through nine with the meter and just make sure nothing's shorter than ain't supposed to be and everything's making the connection to the pad like the 100 ohm resistor the 100 ohm resistor here just going to make sure that it's going through the gate all the way through and I got a hundred on between there and here or that vo there just to make sure everything's good and is still going through the resistor and the resistors didn't get too hot make sure that they're still in good shape they were they were out there I put the put the chips down with the high heat on the on the larger pads of actual drain but after I got through with the the gate and the source and tiny in here I just want to make sure that everything's still good with that excuse the mess setup here I got jumper setup to the phases of the motor you can see my temporary 30 amp automotive fuse here that I just I just have soldered in to the board that's all the replaced MOSFET chips I hadn't even cleaned the board up what alcohol good yet to uh to get all the flux off I have owned everything and everything that should be clear as clear and everything that should be going to the gates going through the one 100 ohm resister through the gates is going through that 100 ohm resistor is good so now I just want to do a test with the jumpers not the best case scenario but the connections are not the best just enough to the runner that no load to see if it runs so I have a ant clamp let's see set it for DC well null it out zero it got my trigger here ready to go [Music] and no load right at three amps it started up good I do want to check especially the green jumper just signifies to me the one that I know is on the problem phase output so I definitely want to check that one and make sure we have current draw on that leg even though it's spun over so good I'm pretty sure it's working all right wanted to make sure all the MOSFETs are connected good and see what it looks like okay what I didn't look too promising check one of the others I know what it is I still got it on DC even though this is a DC input it's actually a three-phase AC sine wave output so go back to AC I'm gonna go back to my green jumper that's my problem channel on my problem face want to make sure I got current on it and it looks good there we go make sure they're fairly balanced so you do need a true RMS AC amp clamp for this checking the output I am very happy with it I'm actually gonna start other connections back back from motor controller I want to do one final test before I actually put it back in the case I'll have to repair the case do it back together and actually put it in and put some silicone in it but before I do that I actually have to get the right fuse - I'm still waiting on the 40 amp a little fuse surface-mount fuse to come in so I was incorrect originally when I said just plug in the battery in I thought the indicator would come on my 16 inch does do that but it might be a newer model than this 14 inch I bought the need of repair so it doesn't do it when you plug it in but it does do it when you hit the switch so just a correction on that the battery indicator that not Immaculate come on until you actually hit the trigger to start them so so one quick thing before I put it back together I got the oscilloscope channel one hooked to one of the phase outputs and the ground since it's isolated through the battery I can go to the other phase output I don't actually have a neutral so instead of going back to the ground of the battery I'm going across the two phases so we look at here what we captured I was just using a single mode we see it kind of strange pulse here looking at it at 100 microseconds we take this a little bit slower we start to see something form here that's all the data I got but we see there that that's our positive and our negative pulses out those pair of MOSFETs to make our actual sine wave [Music] [Music] so the first one was like the sea phase and this one's what I call the a phase I don't know they're actually numbered on mark but that actually here's the channel that we actually repaired so going by the repair we see that we do have our sine wave so that means that both sets of our MOSFETs are working correctly [Music] what we see here is I now have the leads one on each phase but I'm just going to the the negative potential of the battery so I'm not reading negative to positive I can actually only see the positive part of the sine wave but we do see here of the phase shift between the two between the two phases we do see our phase shift if I did have a four channel scope we could see a 120 electrical degrees apart on all three of them of course here I only have two at this point I've let the video go long enough so this repair has been successful it's fully tested I'm not going to wait on a fuse to get here to finish the video all I have left to do is to clean the board up put the right fuse in it put the heatsink back on it and put it all back together and put some silicone on it or a type of potting material to put back over it once I get it back in the in the original housing clean it up and fix the housing and get it put back in the housing so if you enjoy watching this repair of this 14 inch ego chain so please give it a thumbs up if you learned something from it please subscribe and thanks for watching just got this in today can't wait to try it out next up a new microscope camera

Channel: Thrifty Tool Shed

Views: 12,365

Rating: 4.9277978 out of 5

Keywords: EGO, 14, cs1400, cs1401, 56v, dc, 3 phase, brushless, mosfet, board, fr4, solder, repair, bench, microscope, hakko, saw, vhain, controller, electronics, thrifty, flux, fuse.

Id: A-7gFXrxyco

Length: 43min 48sec (2628 seconds)

Published: Sun Dec 23 2018