kiev
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Re: Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter

Fri Jan 31, 2020 11:02 pm

That is a really trashed pair of resistors, and the little one exploded!

Those parts are on the AC Input side. i would want to check all the parts on the top board in the AC input circuit also, e.g. lightning arrestor and fuses, plus the AC relay and EMI filter coils and cap. i would suggest to replace the AC relay since that may have been the culprit that caused the resistors to blow, and it's easier to do it with the waffle plate out of the way.

It looks like your blue snubber caps (on the HV DC Output side) are ok, so i would replace the 20A fuse in the Motor Control Unit as preventative maintenance.
kiev = kenny's innovative electric vehicle

Easky15
Posts: 6
Joined: Fri Jan 31, 2020 1:07 pm

Re: Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter

Sat Feb 01, 2020 11:45 am

kiev wrote:That is a really trashed pair of resistors, and the little one exploded!

Those parts are on the AC Input side. i would want to check all the parts on the top board in the AC input circuit also, e.g. lightning arrestor and fuses, plus the AC relay and EMI filter coils and cap. i would suggest to replace the AC relay since that may have been the culprit that caused the resistors to blow, and it's easier to do it with the waffle plate out of the way.

It looks like your blue snubber caps (on the HV DC Output side) are ok, so i would replace the 20A fuse in the Motor Control Unit as preventative maintenance.



Thanks kiev,

I have updated the google drive folder with more images including the top main board, Fuse F103 on the top AC input board tested good in circuit (do they need to be removed from the board for accurate test) Fuse F102 on the large bottom board also tested ok in circuit,

I have the datasheets here for the ac relay and resistors but where am i best getting them from? Can you please provide links to quality replacement components for all the parts you think i will need, I honestly don't mind spending the extra money here to do it right the first time, Components are relatively inexpensive so I'm happy to replace all possible failures with upgraded/better quality parts, My soldering skills are fairly good so i'd be happy enough doing it all.

Also after repair is complete with new parts fitted is there any sort of waterproofing/insulating material needed to recover soldered area? Looks to be a sort of clear coating over all factory solder joints.???

Virusman
Posts: 3
Joined: Wed Jan 29, 2020 1:21 pm

Re: Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter

Sun Feb 02, 2020 6:24 am

Hi
Easky15
, just visit any web shop with electronic components for example: http://www.digikey.com/ or http://www.farnell.com.
If You want to replace relay, just by exactly the same. Gold rule: don't buy the cheapest one.

My question is: how to test charger without car and batteries? Is it possible?

kiev
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Location: The Heart o' Dixie
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Re: Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter

Sun Feb 02, 2020 8:59 am

Looking at the pictures, Is the Spark Arrestor (SA) okay? Is the plastic base of coil L705 on the top board melted?

i would try to find the same parts online e.g. mouser or digikey, or an electronics parts supplier in Japan if a part is not available from the online sales.

i haven't figured out a way to test an OBC without the car involved since it is CAN buss controlled and tightly integrated with the car. i have tried to publish schematics for circuits that i've traced where component values could be measured, checked and verified to be good. The relay drive circuit was traced and posted too.

For the AC input, those resistors blew because they were carrying the full AC for too long. The question is why and how this happened. Either the relay was never commanded or it opened during charging. The relay is driven by a 5V power supply on the top board created from the 12V aux battery.

Was the aux weak or did it fail during the session; did the 5V supply fail; was the CAN buss signal to start charging corrupted, etc?
kiev = kenny's innovative electric vehicle

Easky15
Posts: 6
Joined: Fri Jan 31, 2020 1:07 pm

Re: Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter

Sun Feb 02, 2020 9:44 am

kiev wrote:Looking at the pictures, Is the Spark Arrestor (SA) okay? Is the plastic base of coil L705 on the top board melted?

i would try to find the same parts online e.g. mouser or digikey, or an electronics parts supplier in Japan if a part is not available from the online sales.

i haven't figured out a way to test an OBC without the car involved since it is CAN buss controlled and tightly integrated with the car. i have tried to publish schematics for circuits that i've traced where component values could be measured, checked and verified to be good. The relay drive circuit was traced and posted too.

For the AC input, those resistors blew because they were carrying the full AC for too long. The question is why and how this happened. Either the relay was never commanded or it opened during charging. The relay is driven by a 5V power supply on the top board created from the 12V aux battery.

Was the aux weak or did it fail during the session; did the 5V supply fail; was the CAN buss signal to start charging corrupted, etc?



Sadly yes it does look like L705 got too hot and melted and also L706 maybe too, Here is some pics

https://drive.google.com/open?id=1JT1Vz ... RUoFwD0wDN

Also how do i test the spark arrestor?? Is it just like testing a fuse? Continuity check? If so it failed that..

Do i need to car to properly diagnose this?

Could this fault be cause by a timer plug cutting AC power every morning before charging is complete?

Or could a weak 12v battery mean 5v supply wasnt able to be generated?


Would an aftermarket charger be an easier option here?
Just need to get power into the batteries...

kiev
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Re: Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter

Sun Feb 02, 2020 10:13 am

The SA should normally measure open circuit, like a capacitor; it is designed to provide a path to ground in the event of a HV lightning pulse.

Since the damage was to the ceramic resistors on the AC input side, then it could be that abruptly cutting the AC power with a timer could be the culprit.

To test if the charger is working properly, it would likely need to be put into a car.

A weak or worn out 12V aux battery will cause a multitude of problems in an EV; since the 5V coil driver power is derived from the 12V battery, then the 12V aux is a suspect culprit.

If you have a benchtop power supply you could follow some of the testing that skylogger Larry did to verify the low voltage supplies of the top board (see pages 8-9 of this thread). also check the fuse on the bottom layer of the top board.
kiev = kenny's innovative electric vehicle

Easky15
Posts: 6
Joined: Fri Jan 31, 2020 1:07 pm

Re: Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter

Sun Feb 02, 2020 10:21 am

kiev wrote:The SA should normally measure open circuit, like a capacitor; it is designed to provide a path to ground in the event of a HV lightning pulse.

Since the damage was to the ceramic resistors on the AC input side, then it could be that abruptly cutting the AC power with a timer could be the culprit.

To test if the charger is working properly, it would likely need to be put into a car.

A weak or worn out 12V aux battery will cause a multitude of problems in an EV; since the 5V coil driver power is derived from the 12V battery, then the 12V aux is a suspect culprit.

If you have a benchtop power supply you could follow some of the testing that skylogger Larry did to verify the low voltage supplies of the top board (see pages 8-9 of this thread). also check the fuse on the bottom layer of the top board.



Ok i will test 12v battery when next at the car, I have power supplies yes so will try these tests,

Also the fuse F701 on the bottom side of the top board is open so that will need replaced too,

Does this even seem repairable or am i safer trying an alternative charger? Is there too much damaged here?

Would really hate to replace everything then plug it all in for it to all go bang again....

Easky15
Posts: 6
Joined: Fri Jan 31, 2020 1:07 pm

Re: Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter

Sun Feb 02, 2020 10:23 am

I also have a Peak Atlas DCA55 Semiconductor Component Analyser here if theres anything else you think i should test?

kiev
Posts: 1070
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Location: The Heart o' Dixie
Contact: Website

Re: Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter

Sun Feb 02, 2020 11:24 am

Easky15 wrote:...
Also the fuse F701 on the bottom side of the top board is open so that will need replaced too,

Does this even seem repairable or am i safer trying an alternative charger? Is there too much damaged here?

Would really hate to replace everything then plug it all in for it to all go bang again....


That is quite interesting and points to an issue on the low voltage power supplies of the top board. F701 is on the switched 12V (aka IGCG?) into the OBC on connector C101 pin 12. From there is goes to a 3.3V regulator, IC718, likely the power supply for the microcontroller on the bottom layer.

The other 12V input is on pin 7, and runs thru a fuse blank FB729, which is a zero ohm resistor that might act as a fuse also, so check it too. It feeds a 5V regulator, IC710, marked M050, and i think this

Capacitors C703, 705, 706, 840 are all on the 5V supply of the top board, and this supply is used to energize the AC relay on the bottom board in the potted region in which the ceramic resistors failed. These should be checked if possible.

So this may all be related to a LV power supply component on the top board and may be a simple repair to replace the components, e.g. a voltage regulator chip. i will look thru my notebook if there are additional circuit schematics that might apply.
Last edited by kiev on Sun Feb 02, 2020 12:16 pm, edited 1 time in total.
kiev = kenny's innovative electric vehicle

Easky15
Posts: 6
Joined: Fri Jan 31, 2020 1:07 pm

Re: Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter

Sun Feb 02, 2020 11:31 am

kiev wrote:
Easky15 wrote:...
Also the fuse F701 on the bottom side of the top board is open so that will need replaced too,

Does this even seem repairable or am i safer trying an alternative charger? Is there too much damaged here?

Would really hate to replace everything then plug it all in for it to all go bang again....


That is quite interesting and points to an issue on the low voltage power supplies of the top board.

Capacitors C703, 705, 706, 840 are all on the 5V supply of the top board, and this supply is used to energize the AC relay on the bottom board in the potted region in which the ceramic resistors failed. These should be checked if possible.

So this may all be related to a LV power supply component on the top board and may be a simple repair to replace the components, e.g. a voltage regulator chip. i will look thru my notebook if there are additional circuit schematics that might apply.


Thanks kiev, ill remove those caps and test then post back results..

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