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

[Piki]

The edit link is now down the bottom of your own posts, just after "Report". There is now a limit of 30 days (was only minutes originally) then the edit option goes away:

View attachment 154

I have the edit option only for the last post from yesterday, the other posts cannot be edited.

 

[Piki]

Definitely check the resistors. The ½Ω measurement is if you turn on the relay with a 4.5 V battery or 5 V power supply.

Ok, so just so I get it right, the top board has to be connected to the bottom board by the ribbon cable. All other cables to the boards can be disconnected, e.g. the boards already removed from the case?
I measure the resistance between the cable terminal you showed and the four solder joints that connect the waffle plate. All four are connected together so doesn’t matter which of those is probed. Without 5 V it should show 9.4 Ohm, and with 5 V it should show 0.5 Ohm, right? Appreciate your help!

 

[coulomb]

Ok, so just so I get it right, the top board has to be connected to the bottom board by the ribbon cable.

Only to energise the relay. But yes.

All other cables to the boards can be disconnected, e.g. the boards already removed from the case?

I think so.

Without 5 V it should show 9.4 Ohm, and with 5 V it should show 0.5 Ohm, right?

There should be a 9.4Ω ±10% difference between the two, and the 0.5Ω is partly multimeter lead resistance.

So around 10Ω, and around zero. The exact values are not important. But yes.

 

[ceskimiev]

Good Morning...

Thanks Kenny for post #1,215, forced me to check all pins in the waffle board connections.

I'm happy and sad i believe I've found the issue. I got a short between pins 25 and 26 plus from there to T4A from the schematic on post #1,197 (thank you LDTVN, left a like). Since I'm not getting shorts on any base-emitter junctions for any of the other bridge IGBTs, I think is safe to say something is shorting on that quadrant of the bridge. May someone please confirm before I go buy a desoldering station and possibly the IGBTs? I haven't found yet a replacement charger and I definitely do not want to pay +3k$ for a new one.

Thanks!

 

[kiev]

i measure about 244Ω between 25/26 on a bare power board with the waffle plate removed. There is a tiny ceramic cap between those two traces on the bottom side, and also a pair 220Ω and 22Ω across them. The drive for these comes off of transformer T502 pins 9 and 10. Found No direct connection to T4A, so there must be something shorting inside the waffle plate.

 

[Piki]

There should be a 9.4Ω ±10% difference between the two, and the 0.5Ω is partly multimeter lead resistance.

So around 10Ω, and around zero. The exact values are not important. But yes.

I get 9.7 Ohms without energizing the relay and 0.2 when energized. So the resistors seems to be ok. One of them is discolored due to the cap exploading on it, but probably it is fine. So the next step is to exchange the two caps and assemble everything back if there are no other suggestions.

 

[kiev]

Are the L and N terminal contacts reading open or some shorting (e,g. shorting thru the puffed capacitor) seems unlikely but worth a check.

If the caps are open circuit, then it seems like they wouldn't have any affect on the circuit with respect to charging?

Maybe post a picture of the entire power board with as high a res as you can get a clear picture, and we'll take a close look for any other parts that might be suspect?

ps i'm not clearly seeing any damage on the cap--too blurry or not good lighting

 

[Piki]

Here are two pictures of the board. No continuity between L and N. But it might be that after running for a while the cap gets hot and shorts those contacts briefly and that is what turns it off. Hard to diagnose an intermittent failure…

 

[Piki]

I see that the pictures were attached as low resolution images, here are the links to the same pictures in high res
Highres 1
Highres 2

 

[kiev]

Highres 2 is a good one; didn't see anything out of place or distressed.

If you are planning to remove the WP, then might as well replace the snubber caps with some newer and higher rated devices; maybe also consider replacing the AC relay.

check the panasonic ZNR surge suppressors on the AC input section of the control board and the lightning arrestors.

 

[Piki]

The ZNRs and the SA look ok to me, no visual signs of damage
Hires 3

I am a bit reluctant to change lots of stuff not knowing if it causes any issues but it is probably the only way forward dealing with intermittent failures. I should have checked the error codes before starting the repair. Tried it but couldn’t read it. Found out only now that the full version of hobDrive can read those. But putting everything together now is too much work.

Anyone have the part number of good snubber caps? Maybe buy those and a relay anyway if I decide to get into the desoldering of WP I will have the parts already. What do you use instead of the black rubber stuff to secure the components in place and protect from vibration? Hot glue is probably not good for caps. Silicon? Or some other special stuff I need to order?

 

[coulomb]

Anyone have the part number of good snubber caps?

There is some discussion starting about here, and part links a few posts down.

@kiev, I think we're in for some misery with the latest forum software. A lot of the old links seem to be page related, and the number of posts per page seems to have changed (maybe doubled from 10 to 20). As a result, all the links carefully collected over years seem to be broken. Maybe we can get the admin to fix this, but I'm not hopeful. It took me ages to track down the snubber capacitor link above, and I don't know if I found the right one. I ended up searching for "6kV" in this thread only.
[ Edit: Maybe archive.org would help. ]

What do you use instead of the black rubber stuff to secure the components in place and protect from vibration? Hot glue is probably not good for caps. Silicon?

I just use neutral cure silicone (the stuff you can buy in tubes). Make sure it's not acetic acid based; that's an acid that conducts electricity. There is better compound that you can buy, but it's really expensive, and I can't see the point.

 

[Rass]

Hi,

I did something very stupid:

The 400V 20A fuse blew, It happened a year ago aswell and then I just put the two leads together to use a CHADEMO charger just so I could drive home. I tried to do the same this time but the pliers holding the leads together hit the aluminium casing and there was a short (small spark) and:

Before the spark the charger was displaying an error which said "Charging stopped by the vehicle" (not even starting)

After the spark it said "No connection to the vehicle, check cable".


What would the next thing up the chain be?
i.e. What did I blow up now and where should I look for the damage?

Cheers

 

[kiev]

@coulomb, you are right about the pain--i stumbled around with the page-referenced links looking for stuff too.

The other problem is not being able to edit old posts that might need to be updated or corrected.

The updated forum software is so recent that i was just waiting to see how it plays out for a bit.

 

[Rass]

Hi,

I did something very stupid:

The 400V 20A fuse blew, It happened a year ago aswell and then I just put the two leads together to use a CHADEMO charger just so I could drive home. I tried to do the same this time but the pliers holding the leads together hit the aluminium casing and there was a short (small spark) and:

Before the spark the charger was displaying an error which said "Charging stopped by the vehicle" (not even starting)

After the spark it said "No connection to the vehicle, check cable".


What would the next thing up the chain be?
i.e. What did I blow up now and where should I look for the damage?


EDIT:
ok, I will look here:
https://myimiev.com/threads/troubleshooting-and-repair-for-on-board-charger-obc.4079/
and here:
https://myimiev.com/threads/gen1-dcdc-converter-troubleshooting-and-repair.4737/#post-41793

Any help is much appreciated!

Cheers

Nothing seems to be burnt on the charger side... Although I could smell... Hot electronics when opening it up... Not too much tho..

 

[kiev]

There is a fuse inside the OBC over at the HV Output on the lower power board, probably hidden under the bundle of wires, might be worth a check. Never seen one fail before but this is a situation never seen before.

 

[Rass]

There is a fuse inside the OBC over at the HV Output on the lower power board, probably hidden under the bundle of wires, might be worth a check. Never seen one fail before but this is a situation never seen before.

That one is fine, next to the pink and blue wire.

While there I noticed something weird.

In addition to that weird there was an "unplugged" hole in the housing next to the "weird" area. That is the reason for the dust.

Pictured is the pink and blue wire plugs, the pink one has a darkened area next to it... But the connector on the pink wire is looking mint...

First thought is that it is something underneath that has burned.

Hey! Have a beautiful new years eve Kiev! Thanks for the input


Edit:

Yes, The brown-orange between the blue cap and the burned area is exposed copper

Edit2:

Here are a few better pictures of the unplugged hole. It's crazy that I can see the wheel directly through it





Edit3:

Tried the AC charger again, now its working.

Also the dc-dc is working. Getting 14.6V at the battery.

So:

First, I am really stupid, haha

Second, I will go retry the ChademO tomorrow, with a full 12V battery and see maybe my problem yesterday was that it was low. And pray that the spark I saw was of no consequence. Will report back with what I find.

 

[coulomb]

The other problem is not being able to edit old posts that might need to be updated or corrected.

We have 3 months, at least on the sister Leaf forum, also recently updated. That might be awkward, but it might force starting new, cleaner posts with just the most relevant posts included. Or probably the new post starts off as mostly links to posts in the older thread.

But I think you'd want some sort of automation to make that less painful. I can't offhand think what that looks like.

I've been thinking about this sort of thing for some of the indexed mega posts that I have edit permission for.

 

[kiev]

@Rass, there is supposed to be a black plastic plug in that vent hole to prevent dirt and water from getting in. i suggest you put some tape over the hole temporarily and clean all that oxidation mess out of there (vacuum, brush, vinegar, neutralize with baking soda, rinse with alcohol, coat it with grease).

It appears that some arcing occurred where the bare copper is showing on that trace, but i can't see it clearly with the low res picture.

@coulomb, i'm open to suggestions if you have ideas on how to deal with the forum and edits, etc.

 

[Rass]

That one is fine, next to the pink and blue wire.

While there I noticed something weird.

In addition to that weird there was an "unplugged" hole in the housing next to the "weird" area. That is the reason for the dust.

Pictured is the pink and blue wire plugs, the pink one has a darkened area next to it... But the connector on the pink wire is looking mint...

First thought is that it is something underneath that has burned.

Hey! Have a beautiful new years eve Kiev! Thanks for the input


Edit:

Yes, The brown-orange between the blue cap and the burned area is exposed copper

Edit2:

Here are a few better pictures of the unplugged hole. It's crazy that I can see the wheel directly through it

View attachment 183View attachment 182



Edit3:

Tried the AC charger again, now its working.

Also the dc-dc is working. Getting 14.6V at the battery.

So:

First, I am really stupid, haha

Second, I will go retry the ChademO tomorrow, with a full 12V battery and see maybe my problem yesterday was that it was low. And pray that the spark I saw was of no consequence. Will report back with what I find.

Fast charging still has the following symptoms:

"

Before the spark the charger was displaying an error which said "Charging stopped by the vehicle" (some clicking)

After the spark it said "No connection to the vehicle, check cable".
(Complete silence)

"