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

[bigpete]

Thanks misterbleepy, I will try them.

 

[coulomb]

I thought I saw a post where someone, possibly Kiev, had found a source for replacement MCU fuses that were close enough to the originals to be usable. I can't seem to find that post now; perhaps it's in a different topic. Anyone have a link? I know the fuses are tough to find.

Apologies in advance if I'm just bad at searching.

 

[kiev]

No problem, i couldn't find it with a search either; then realized it was posted elsewhere.

There is a MCU fuse investigation thread with analysis, theories and simulations to figure out why it is failing, and purchasing info from Mouser, (it is the 10.3 diameter not the 7.2mm)

http://myimiev.com/forum/viewtopic.php?f=22&t=4310&hilit=MCU+fuse&start=10#p39900

[edit: Joe recommended to Boldface the font to help future folks searching for this]

 

[coulomb]

No problem, i couldn't find it with a search either; then realized it was posted elsewhere.

Ah, thanks! I'd forgotten that topic.

There is a MCU fuse investigation thread with analysis, theories and simulations to figure out why it is failing, and purchasing info from Mouser, (it is the 10.3 diameter not the 7.2mm)

Ah! To be clear, you're saying that the original Mitsubishi fuse is actually 10.3 mm diameter, not the 7.2 mm diameter that the earlier posted PDF refers to, in the index? So the index should refer to this drawing instead? If so, that clears up a lot of confusion (on my part, at least).

Edit: so the fuse I found in this post is possibly also a good, if not exact, fit.

 

[nuggetgalore]

No problem, i couldn't find it with a search either; then realized it was posted elsewhere.

Ah, thanks! I'd forgotten that topic.

There is a MCU fuse investigation thread with analysis, theories and simulations to figure out why it is failing, and purchasing info from Mouser, (it is the 10.3 diameter not the 7.2mm)

Ah! To be clear, you're saying that the original Mitsubishi fuse is actually 10.3 mm diameter, not the 7.2 mm diameter that the earlier posted PDF refers to, in the index? So the index should refer to this drawing instead? If so, that clears up a lot of confusion (on my part, at least).

Edit: so the fust I found in this post is possibly also a good, if not exact, fit.

Hello Coulomb ,kiev and all the contributors,
so glad I found you here and on the AEVA site.

I just read some more pages of this huge library of iMiEV knowledge.

I now removed the blown fuse and can confirm the 10.3 mm diameter and 53 mm slot spacing . Bolt is 5mm dia, assuming M5 but have not verified the pitch.
Anyway, fuse replacement is going to wait until the OBC is repaired.
Cheers Andy

 

[nuggetgalore]

Electropusher: The charger label on your charger has the same Mitsubishi part number 9481A092 as the charger that I just repaired.
Both are in 2010 I-MIEVs here in Australia that were built in Japan.
You also have the vertical PCB with blown caps in the dog house, VS the older style that had the through hole caps that the vertical PCB emulates. The fault on the one I repaired ended up being a poor solder connection of a 39K 0603 resistor close to where the flex cable connects the top PCB to the bottom PCB of the charger boards. I noticed that when I tried resoldering the 39K resistor, it would not re-solder properly and I found the end caps of the 0603 resistor did not have all of the plating on them. It would be interesting if your charger and my charger happened to be made in the same batch, of the same reel of SMD resistors (with faulty end cap plating), and you also had a bad solder connection in the same area that I had. I think there are actually 2 of these 39k value resistors in this circuit. My charger probably worked for a while until vibration caused the poor cold solder joint to the resistor to open. The lack of solder plating on the ends caps of the resistor is probably why during the manufacturing process, when the PCB was going through the oven, its mounting twisted a bit because the solder past only barely connected and held one end down and it floated a bit.

I think you will find when you dig out the rubbery potting around the vertical PCB in the doghouse, the only damage is the SMD Caps on the vertical pcb. The two spots that look like something else is burnt in front and to the right of the vertical PCB is where the shrapnel from the caps of the vertical PCB Caps has landed, and melted back into the potting. If you dig there, you will find no actual components under that area on
the main PCB. KIEV found the cap values on the other thread and the Murata info is:
DEHR33F102Kppp 3150Vdc 1000pF±10% 13.0mm max. 7.5 6.0mm max. A3B B3B N3A
I used 2 of these through hole caps and soldered to the four pins that connected the vertical PCB to the main board by removing the vertical PCB and soldering the caps to the remaining pins sticking up. I replaced with Altronics equivalents.

Reading through this very long thread I realise that my 2010 iMiEV also sports a newer 2015 charger with now the identical problem.
Edit:added photo of part no, s/n and date
https://imgur.com/oqI0S2K
https://imgur.com/a/75PEnVn
I have dug some of the potting around the vertical CB and was going to ask if replacing the caps on the board or as per kiev's method is preferable .Now a third method to contemplate.

 

[kiev]

I have dug some of the potting around the vertical CB and was going to ask if replacing the caps on the board or as per kiev's method is preferable .Now a third method to contemplate.

Even with the newer style enclosure from 2015, it appears that the inner boards may be the same as the 2012--can you post up a photo with the lid off to the side so we can see the insides to be sure.

i like the repair that Simon [DBMandrake] did and that i have seen some others do, as long as the bending of the leads doesn't crack the epoxy coating on the capacitor, i.e. don't bend without needle nose pliers to hold the lead base without strain.

but skylogger was the first to make a successful repair and he had the little circuit board with caps such as you do. It would be worth reaching out to him with private message or a phone chat to get his opinion.

My method of cutting the sides of the doghouse box is probably too much work for questionable benefit. Better to solder the leads into the holes already on the board, or to the remaining stubs of the damaged caps or board.

 

[nuggetgalore]

I have dug some of the potting around the vertical CB and was going to ask if replacing the caps on the board or as per kiev's method is preferable .Now a third method to contemplate.

Even with the newer style enclosure from 2015, it appears that the inner boards may be the same as the 2012--can you post up a photo with the lid off to the side so we can see the insides to be sure.

i like the repair that Simon [DBMandrake] did and that i have seen some others do, as long as the bending of the leads doesn't crack the epoxy coating on the capacitor, i.e. don't bend without needle nose pliers to hold the lead base without strain.

but skylogger was the first to make a successful repair and he had the little circuit board with caps such as you do. It would be worth reaching out to him with private message or a phone chat to get his opinion.

My method of cutting the sides of the doghouse box is probably too much work for questionable benefit. Better to solder the leads into the holes already on the board, or to the remaining stubs of the damaged caps or board.

G'day,
so pleased that I can access your (and all the others) vast experience, very much appreciated.
https://imgur.com/a/iQyYHqF
https://imgur.com/a/wolOdqd

 

[kiev]

That's a really clean OBC, looks brand new inside. It has the same boards as the previous years so this thread applies to your situation. Hopefully some new capacitors and a fuse will have you fixed right up.

The design of those snubber capacitors seems to have changed over time, probably in an attempt to solve the blowing capacitor issue. We don't have any Japanese folks on this forum, but i'll bet they had a rash of failures over there that prompted the change.

 

[clovi]

Hi everyone.
After a battery warranty on my oldest IMIEV, the Bianco, (It's doing great, 99.500 miles) I have the same DC to DC converter problem with my wife's IMIEV, the Vino (48.000 miles).
Of course, Mitsu is not giving any warranty or help.
Thanks to all you guys, I could open the box.
I can see both white resistors burned and probably 1 of the big capacitors, I think.
Could I send this to someone to fix? I don't have the knowledge and/or tools to do it.
Seems that KIEV/Coulomb do it? Please let me know.
Thanks,

 

[coulomb]

Seems that KIEV/Coulomb do it?

Just be aware that I live in Australia, and don't own an iMiEV. Shipping from the USA to and from Australia would be totally impractical. Especially in the Covid era.

 

[nuggetgalore]

Hi all,
good news : chargger fixed.
Thanks to all for the tremendous help from the contributors here and on the AEVA fora and also the fuse one

http://myimiev.com/forum/viewtopic.php?f=22&t=4310

Yes the fuse(s) from Mitsubishi were "only" 28 bucks each, not bad considering the other not so easy and more expensive options.
The replacement of the caps ( I ordered four from RS in case I break them at a first attempt) needed steady hands and a bit of bush craft experience. I'm quite proud of myself,lol.

Now that my chargger and the 12V DC-DC converter are working again, I am wondering what every bodies thoughts are to prevent this to happen again (resp prevent it happen to the other iMiEVs that get a bit long in the tooth.
By the way, I checked my two J1772_ cables I use mostly for charging. The resistance between the earth pin and pin PP (plug present or proximity pilot) is the correct 150 Ohms when locked and the additional 300 Ohm (450 total) when the release trigger is pressed. Pressing the release trigger terminates charging immediately as I can observe on an analog current clamp meter. As I have repeatedly not charged the battery to completely full, aborting the charging with a timer, obviously the termination would not have been commanded by the pin PP signal. If that contributed to the weakening of the 20A fuse and or the caps is one of the questions that are worth answering. Of course the same abrupt disconnect of the
240 VAC could happen if the grid failed, but that would not happen very often.
Other reasons may be a poor auxiliary battery, just old age or what do you think?
From now on I will endeavour to let the car to end charging or let the 450 Ohm resister command the charge end.
Maybe if the corona lookdown drags on, I find time to modify the plug with a micro relay so the timer (PLC) can open and shut the 450 Ohm resister circuit? One has to have dreams.....

Cheers and keep safe,

 

[kiev]

...
Thanks to all you guys, I could open the box.
I can see both white resistors burned and probably 1 of the big capacitors, I think.
Could I send this to someone to fix? I don't have the knowledge and/or tools to do it.

Where are you located?

If you were able to open the box, then i think you have the skills to also remove the circuit boards from the box.

It would be much less weight for shipping if required, but the other option would be to take the board to a TV or Electronics Repair shop in your local area. They would have the tools and knowledge to replace the parts.

 

[clovi2]

Where are you located?

If you were able to open the box, then i think you have the skills to also remove the circuit boards from the box.

Hi KIEV.
Thanks for the fast response.
I'm in Leesburg, VA. Seems not far from you.
I already opened the box and took the PCB out. I am really grateful for all your help with all the posts, pictures, etc...
Yes, I can ship to you, if you're willing to fix.
You can send me a private message. I opened another account (clovi2). For some reason, my previous membership name (clovi) doesn't work.

One more time, thanks for all your help.

Clovis

 

[clovi2]

Hi everyone.
I just spoke with KIEV minutes ago.
He told me that the converter now has a 10-year warranty. Would it be possible for someone to get a photo of this document?
Thanks one more time. Thanks KIEV. You guys are awesome.

Cheers,

Clovis

 

[clovi2]

HI everyone.
Thanks to Kiev's info., I could get a warranty on the On-board Charger (OBC), DC-DC Converter.
One more time, my dealer Renn Kirby Mitsu in Frederick, MD call their Mitsu rep., received the part, perform the service and delivered the car.
I'm thankful for Kiev's call, information and help. Thanks also to Mitsu and their case manager Grafton, to Renn Kirby and their service manager John and their tech Russel. They are all great people.

Cheers,

Clovis

 

[Turnik79]

Hello everyone. Someone can measure the C545 rating. It is located on the back of the top board. Thanks in advance. After OBC repair, there was error U111D. Found a burnt out element C545
https://imgur.com/D1KBjS5

 

[coulomb]

Found a burnt out element C545

Eek. Judging by the thick track that appears to be leading from it, and its proximity to the chip, I'd guess it's a supply bypass capacitor. For that to burn, I'd expect a lot more carnage elsewhere, unfortunately.

Good luck!

 

[kiev]

IC509 is an MB3793 Power Voltage Monitoring ic from Fujitsu.

"A reset signal is output when the power is cut or falls abruptly. When the power recovers normally after resetting, a power-on reset signal is output to microprocessor units (MPUs). An internal watchdog timer with two inputs for system operation diagnosis can provide a fall-safe function for various application systems."

The C545 is a decoupling capacitor between the 5V Vcc and ground. The chip draws very little current, 31uA, nominally after power-on reset.

The value of the capacitor could not be measured in circuit due to all the electrolytic capacitance holding up the 5V buss on the top side of the board; maybe i can lift the part tomorrow and get a reading. i don't think it is a critical value like the capacitors on pins 2 and 3 which set the timing for the monitoring. i think you could use a 0.1 or 1 uF cap and the circuit would function if the chip was not damaged.

What happened to your capacitor--was it shorted or did it get blown off the board? Was there an overvoltage event associated with the failure? If shorted it would prevent the Vcc from rising and the micro wouldn't be turned on.

The same chip is also used on the Laef OBC as IC509, and it uses 2 decoupling caps, C545 and C730, and a ferrite bead, FB506, on the 5V to Vcc.

Example usage:

 

[Turnik79]

What happened to your capacitor--was it shorted or did it get blown off the board? Was there an overvoltage event associated with the failure? If shorted it would prevent the Vcc from rising and the micro wouldn't be turned on.

a vertical board was blown up (replaced with blue caps) and a 20A fuse in the MCU. also replaced by 20A for solar panels. OBC now works well, but there is no slow charging.
s545 burned and torn off the board