The Troubleshooting and Repair for On-board Charger (OBC) Thread

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Thank you!i checked the resistance between 1 point(near blue capacitors) and each of 4 points N ,it is 10,2 Ω

All 3 boards and radio elements seem to be intact. I checked the inductors on the large board, they all have a resistance of about 0.7 Ω,so I think there is no inter-turn shorting, but the stench comes from them. all the fuses are intact.I cannot check ceramic capacitors, have no special device

the ordinary charger 120 v 8 a looks good, when it's connected to the outlet without a car, a green lamp lights up, I don’t know how to check it, maybe the main reason was on it, after the last charging, the false yellow lamp was on. maybe the voltage in the network jumped, I wonder how much volts more than 120 is critical for my charger, cause sometimes the network shows 119-122,I think it is not significant.nobody knows how many was in this moment.but I tried to charge from other chargers in my city, the same story
It looks to me as if the X2 capacitor is blown. I had the same issue and change it but not 100% sure if it was causing the charging problem, had also a bad contact to the 12V battery, as identified later. If it is blown may be worth to change it before assembly. But the 12V battery needs to be changed anyway
 

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The 12V battery is critically important for an EV, and not something you want to skimp on, or play around with trying to squeeze the last bit of use out of--it can result in expen$ive damage to nearly unavailable components.

Check the fuse under the access cover of the motor control unit aka drive inverter, located to the right of the OBC. If that fuse is blown then the DCDC converter located in the bottom plenum of the OBC will not get power to recharge the 12V battery, nor will it allow the OBC to charge the main HV pack (traction battery).

Nothing obviously blown in the OBC, eg precharge resistors, snubber capacitors. i suspect the bad 12V battery may be the root cause of your problem. Remedy that first, then try to drive/charge your car.

You could do the waffle plate diode drop checks while you have that power board out and disconnected, see coulomb's post #1308 on this page for a diagram with expected voltage drops.
Regarding the obd tool your only option is Car Scanner ELM OBD2, but it requires the expensive OBD-link dongle. There is also Hobdrive paid version but that is not an option, because russian
Удачі з пошуком поломки і ремонтом!
 
It looks to me as if the X2 capacitor is blown. I had the same issue and change it but not 100% sure if it was causing the charging problem, had also a bad contact to the 12V battery, as identified later. If it is blown may be worth to change it before assembly. But the 12V battery needs to be changed anyway
I was thinking about this place too, it looks weird,but i compared it with another photos i had seen.i guess i have the same.probably it is a shadow of gray hermetic
 
I was thinking about this place too, it looks weird,but i compared it with another photos i had seen.i guess i have the same.probably it is a shadow of gray hermetic
Can you make a better close up picture of that area? The color of “puke” looks similar to what leaked from my X2 capacitors
 
Can you make a better close up picture of that area? The color of “puke” looks similar to what leaked from my X2 capacitors
 

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Good eyes Piki, that definitely looks like a failed capacitor or resistor to me.

You need to carefully dig out that black rubber potting so you can see down to the board and inspect at the bottom of the capacitor. Look at the pictures on the first page of this thread for examples of failed caps.

Do you measure the 9-10 Ohms across the two white ceramic resistors?

What about the diode voltage drops for the waffle plate--does the plate measure okay?
 
Good eyes Piki, that definitely looks like a failed capacitor or resistor to me.

You need to carefully dig out that black rubber potting so you can see down to the board and inspect at the bottom of the capacitor. Look at the pictures on the first page of this thread for examples of failed caps.

Do you measure the 9-10 Ohms across the two white ceramic resistors?

What about the diode voltage drops for the waffle plate--does the plate measure okay?
Yes,I measured resistors : 10.2 ohms- relay off and 0.8 ohms -relay on.
which diode do you mean and how to measure it?
 
Yeah, that cap is shot. It is however unclear how it affects the charger, as discussed previously in the thread. If it burns open it should “only” cause a higher electromagnetic interference and if it burns closed the fuse should blow. Might be that it burns halfopen and causes excessive heating which shuts the charger off. Anyway, probably better to replace it. You can check page 64 of this thread to see how I did it. I can share a link to the caps I bought from Mouser, but not sure if it is available in Ukraine. Anyway, any caps of the same dimension, class and capacity should work.
Good luck with the repair. Removing the putty takes time, removing the cap piece by piece takes ages
 
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Yeah, that cap is shot. It is however unclear how it affects the charger, as discussed previously in the thread. If it burns open it should “only” cause a higher electromagnetic interference and if it burns closed the fuse should blow. Might be that it burns halfopen and causes excessive heating which shuts the charger off. Anyway, probably better to replace it. You can check page 64 of this thread to see how I did it. I can share a link to the caps I bought from Mouser, but not sure if it is available in Ukraine. Anyway, any caps of the same dimension, class and capacity should work.
Good luck with the repair. Removing the putty takes time, removing the cap piece by piece takes ages
Yes , please.i'll try to find them
Thanks great!)
 
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Update:
Replaced two X2 caps with new ones. Was hard to desolder from the small "external" board even with a soldering station, lots of thermal mass around (and also a wrong soldering iron tip). At the end ripped the X2 apart and thought to practice before doing the same with the lower board in the OBC. After an hour of carefully removing it got two contacts to soleder to, but finally desoldered it altogether and installed a new one the traditional way. That X2 was more like one solid piece of molten plastic inside, was easier to rip apart. The X2 on the lower board was damaged on one side only (molten inside) so it was actually harder to rip apart since I was pealing the layers of foil one by one and there are literally thouthands of layers inside. In the end ripped it apart, soldered a new one in a laying position and assembled back. Lots of neutral silicon around/under. New thermal paste.

Tried to charge at 14 A and it stopped after around 45 min ... because my circuit breaker popped, turned out I had only 10A breaker at those sockets :D. Charged at 8 A all the way. After that probably around 5 charges at 8 A from 30% to 100% and once at a public charging station at 3,1kW max. No problems so far, no stops. Fingers crossed.

Was it X2s causing the issue? Not entirely sure. When connecting back the 12 V battery tightened the clamps firmly and just gave it a slight wiggle just to be sure it sits good ... and the negative terminal was loose. The clamp is of a strange design, it might bended a bit and then was not grabbing the pole even if screwed really tight. Bended it back a bit and now it sits good. Not sure if that could be a factor, it wasn't totally loose but not fully tight anyway.

how was the fuse on input AC board?it was intact? how did you check the relay on it?
 
how was the fuse on input AC board?it was intact? how did you check the relay on it?
The fuse was intact. What do you mean regarding the relay? I see you have already checked it since you wrote resistance with the relay on and off. I did the same way and got similar values
 
The fuse was intact. What do you mean regarding the relay? I see you have already checked it since you wrote resistance with the relay on and off. I did the same way and got similar values
Sorry,i meant this capacitor
 

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Sorry,i meant this capacitor
It was obvious visually that both of them were gone. The one on the external board leaked some brown liquid that left deposit on the board on the right side in the picture. Also, grey plastic leaked on the right side, similar color as yours. The one on the lower board was less obvious, it was swollen on the side close to resistors and had a small hole/blurb of plastic. Have no good picture but a bit visible on the one attached. Inspect the one on the external board but if you don’t find anything strange, just leave it. It is not that easy to desolder.
 

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It was obvious visually that both of them were gone. The one on the external board leaked some brown liquid that left deposit on the board on the right side in the picture. Also, grey plastic leaked on the right side, similar color as yours. The one on the lower board was less obvious, it was swollen on the side close to resistors and had a small hole/blurb of plastic. Have no good picture but a bit visible on the one attached. Inspect the one on the external board but if you don’t find anything strange, just leave it. It is not that easy to desolder.
understood, thank you. yes, everything is quite clearly visible on your board. I will probably put everything back, change the 12 v battery and try. although there is little hope, I think something happened with the capacitors in the dog house and the unknown condition of the waffle plate, although I illuminated it with a flashlight, everything seems to be OK.maybe it would be worth to make a resoldering. but the stench that has not gone anywhere... So let's see, maybe a miracle will happen)
 
Hello!It works again!))the water pump starts every 3 minutes and works for 25 seconds.i believe it is normal, isn't it?I haven’t closed the cover yet, it’s quite warm there. thank you very much to everyone who took part in solving this issue,without y'all guys,I wouldn't be able to do it .I’m very happy that the charging is going...yet)))
 
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but the stench that has not gone anywhere...
They do get quite hot in operation, and that causes some smell from insulation off-gassing. It also causes the clear tubing around many of the wires to go dark. But some amount of that smell and heat is normal. It's hard to tell without being there if it's normal smell and heat.

Hello! It works again!
Congrats! Let's hope it's fixed for good. These chargers really do have "some user serviceable parts inside" 😎
 
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They do get quite hot in operation, and that causes some smell from insulation off-gassing. It also causes the clear tubing around many of the wires to go dark. But some amount of that smell and heat is normal. It's hard to tell without being there if it's normal smell and heat.


Congrats! Let's hope it's fixed for good. These chargers really do have "some user serviceable parts inside" 😎
I hope,we will see)
Appreciate it!
 
Hello!It works again!))the water pump starts every 3 minutes and works for 25 seconds.i believe it is normal, isn't it?I haven’t closed the cover yet, it’s quite warm there. thank you very much to everyone who took part in solving this issue,without y'all guys,I wouldn't be able to do it .I’m very happy that the charging is going...yet)))
So you didn’t change anything, only new battery solved the issue, right?
 
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