Cranium Posted November 24, 2015 Author Share Posted November 24, 2015 5 minutes ago, esaj said: Are you sure it's thermal adhesive? Pretty sure. They are using a strip of Kapton tape to electrically isolate the heatsink. I removed the screws on the MOSFETs but couldn't get them to budge at all when trying to remove the heatsink. I stopped short of using something mechanical to pry them off. They are on there good! Link to comment Share on other sites More sharing options...
Cranium Posted November 24, 2015 Author Share Posted November 24, 2015 38 minutes ago, esaj said: in most non-SMD mosfets the metallic back-plate part is connected to one of the pins, so I could have connected some pins of the mosfets (gates?) together. Yes, this would have been bad. The voltage on most of mine are at battery voltage. But there are a couple that are at 0 volts when the board has power which I'm assuming are the blown ones. I also have other MOSFETs that appear to be stuck open (all pins have continuity to ground) which isn't good either. So there are probably 6 that would be targeted for replacement. I'm wondering if these took out anything else when they blew (i.e. some of the transistors for the gates). The surface mounted transistors and other small components would be a pain to replace. I have a hot air rework station to do it but not much experience working with it. The waterproof coating on the board would become problematic at this point too. Link to comment Share on other sites More sharing options...
Kevin Lee Posted December 6, 2015 Share Posted December 6, 2015 Hi. Anyone know the pinout of the charger plug for the Ninebot One? i.e. Which pin number is + and which one is -. Thanks and in advance. Link to comment Share on other sites More sharing options...
esaj Posted December 6, 2015 Share Posted December 6, 2015 38 minutes ago, Kevin Lee said: Hi. Anyone know the pinout of the charger plug for the Ninebot One? i.e. Which pin number is + and which one is -. Thanks and in advance. Rotator posted a picture of the pins here: http://forum.electricunicycle.org/topic/867-charging-in-a-car/?do=findComment&comment=10476 Link to comment Share on other sites More sharing options...
9bots Posted December 7, 2015 Share Posted December 7, 2015 On 24/11/2015, 23:51:26, Cranium said: Yes, this would have been bad. The voltage on most of mine are at battery voltage. But there are a couple that are at 0 volts when the board has power which I'm assuming are the blown ones. I also have other MOSFETs that appear to be stuck open (all pins have continuity to ground) which isn't good either. So there are probably 6 that would be targeted for replacement. I'm wondering if these took out anything else when they blew (i.e. some of the transistors for the gates). The surface mounted transistors and other small components would be a pain to replace. I have a hot air rework station to do it but not much experience working with it. The waterproof coating on the board would become problematic at this point too. Hi there. Any updates on your motherboard replacement? Did you managed to get the unlock code you mentioned? Coz I'm having exactly the same problem as you you described it in the first post. Link to comment Share on other sites More sharing options...
Cranium Posted December 7, 2015 Author Share Posted December 7, 2015 1 hour ago, 9bots said: Hi there. Any updates on your motherboard replacement? Did you managed to get the unlock code you mentioned? Coz I'm having exactly the same problem as you you described it in the first post. Hi. Yes, I was only down for 8 days total. I was lucky with my timing I guess. The replacement board was shipped and arrived after about 5 days and the code took just an extra day. I imagine they are getting slammed right now with the replacement boards from the 1.2.9 debacle. Link to comment Share on other sites More sharing options...
9bots Posted December 7, 2015 Share Posted December 7, 2015 29 minutes ago, Cranium said: Hi. Yes, I was only down for 8 days total. I was lucky with my timing I guess. The replacement board was shipped and arrived after about 5 days and the code took just an extra day. I imagine they are getting slammed right now with the replacement boards from the 1.2.9 debacle. Wow that's great news. I'm happy for you. Wanna know what's funny? Well here's the story. I bought my ninebot one at the middle of October and that time, I told the sales person if they have a vacancy, I'd like to apply for a job. Fast forward a month later, I got the call from him and here I am, on my 3rd week. I have learned how to service the Ninebot mini flight and the Ninebot One so far, and we're doing rentals at a resort here. It just so happen that last week, I was practicing for some fancy stunts on my ninebot one and it crashed the wall before tumbling over (normal accident, nothing spectacular). Since then, it has suffered the problem like you mentioned in the first post. I let him know about the problem and he said he will help me to claim for warranty. Since we worked together all the time everyday, I don't wanna bother him by nagging too much to get it to fix. What's frustrating was, he only asked for the serial number and other info after the 4th day it has been broken (which happens to be on a Friday). I was also left in the dark as to the procedure needed to be taken to claim a warranty. If I was briefed on that, at least I could have done it in my own. To add insult to injury, the replacement motherboard is just there in the inventory store. It's been 11 days without my ninebot one now. What a joke. We are the sole distributor for Ninebot in our country. Sigh. Link to comment Share on other sites More sharing options...
Steven Dilema Louis Posted July 8, 2017 Share Posted July 8, 2017 On 2015-11-24 at 3:03 PM, esaj said: Are you sure it's thermal adhesive? Could be just thermal pads like these: http://www.aliexpress.com/item/10mm-10mm-1mm-100-pcs-Thermal-Pad-GPU-CPU-Heatsink-Cooling-Conductive-Silicone-Pad-high-quality/32259809537.html The Firewheel mainboard had similar stuff like that between the heatsink and the surface-mounted mosfets (these: http://cdn-reichelt.de/documents/datenblatt/A100/DS_IRF7759.pdf), it wasn't adhesive, but just held in place by the bolt of the heatsink going through the PCB (might not be very efficient cooling, I think). As it looks like the Ninebot mosfets are also screwed to the heatsink, I doubt they'd need to use adhesive (but they still could have). Replacing the old thermal stuff with something like those pads (it's also available as bigger mats that can be cut) could work, as long as it conducts heat good but not electricity. I originally thought I'd replace the pad in the Firewheel with just thermal paste, but learned that at least in most non-SMD mosfets the metallic back-plate part is connected to one of the pins, so I could have connected some pins of the mosfets (gates?) together... And once I took the heatsink off, I could see getting the paste "right" wouldn't have been easy anyway. Hey esaj, do you know ow which of the pins are connected to the motherboard backplate? Also where on the board word the earth lead connect? Thanks for any help Link to comment Share on other sites More sharing options...
esaj Posted July 8, 2017 Share Posted July 8, 2017 1 hour ago, Steven Dilema Louis said: Hey esaj, do you know ow which of the pins are connected to the motherboard backplate? Also where on the board word the earth lead connect? Thanks for any help On Ninebot-board, no, never seen one in real-life. If you meant the mosfets, it's the middle pin, usually drain, don't remember seeing TO-220 -mosfets with other pinout than GDS (Gate - Drain - Source) when looked from the "front" (text-side) of the component. There's likely a ground-plane (what I think you meant by "earth") on the backside of the board. If you need ground for making measurements or something, you could use the black battery cable or the point where it connects to or trace from there (with the battery disconnected & caps drained first) to find a more suitable spot We'd need a thread with mainboard pictures of each wheel to refer to easily... The metal platings around the screw holes might be connected to ground? At least they seem to be ticked with vias: The other ends of the shunt-resistors might also be connected to ground, but can't say for sure. Link to comment Share on other sites More sharing options...
Rehab1 Posted July 8, 2017 Share Posted July 8, 2017 4 hours ago, esaj said: We'd need a thread with mainboard pictures of each wheel to refer to easily... Excellent idea!!! I nominate @esaj! Are you thinking of a thread that is closed to communication but just contains pictures of the boards with a reference to the manufacturer and any relevant codes/ dates? Link to comment Share on other sites More sharing options...
esaj Posted July 8, 2017 Share Posted July 8, 2017 14 minutes ago, Rehab1 said: Excellent idea!!! I nominate @esaj! Are you thinking of a thread that is closed to communication but just contains pictures of the boards with a reference to the manufacturer and any relevant codes/ dates? It doesn't need to be closed (locked), but would need to be moderated so it stays on topic. Or just edit the first post to contain the images, adding as new ones are posted on the thread by others. Likely won't get around to it any time soon... Link to comment Share on other sites More sharing options...
Rehab1 Posted July 8, 2017 Share Posted July 8, 2017 5 minutes ago, esaj said: It doesn't need to be closed (locked), but would need to be moderated so it stays on topic. Or just edit the first post to contain the images, adding as new ones are posted on the thread by others. Likely won't get around to it any time soon... Yes I know you are very busy! Definitely keep your idea on the back burner! Maybe someone will eventually run with it. Link to comment Share on other sites More sharing options...
alin_arghira Posted April 16, 2018 Share Posted April 16, 2018 Hello. Any updates with mosfet replacement? If your answer is yes, the bot worked after replacement? It's hard to replace this mosfets? Any rules to follow? I have the same problem with my one E+, dead after 1 week/75 km, the green mboard. I'll try to change myself the mosfets, so any advice is very good for me. I tried to contact ninebot service to help me, but they sent me to the seller to take care of my 9bot. The shop is in China too, bought from aliexpress. Now i'm very dissapointed, new bot dead and no help from ninebot official service. I am constrained to repair myself the bot, after i spent 700 € on this. Thank you in advance. Link to comment Share on other sites More sharing options...
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