kiev
Posts: 1456
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

Re: Troubleshooting by replacing boards?

Fri Apr 16, 2021 10:47 am

The first page of this thread was organized such that the entire 66 pages do not have to be read to find and fix a failure of your OBC. You just need to read the first page and you can fix it. Is that too much?

On the first page is a list of people and a link to their problem, and if they fixed it, there is a description and sometimes a link to where they explained what they found and how they repaired it. Maybe this is useful?

In the list of pictures are examples of the type of damage found by many different folks. That could be useful for comparison of what is inside your unit if you decide to remove the cover?

As far as i know, nobody here has ever tried replacing boards to find a problem; you would be the first to want to try such a risky and potentially expensive troubleshooting technique. Is that how you repair electronics?
kiev = kenny's innovative electric vehicle

Matheos
Posts: 22
Joined: Tue Jun 16, 2020 5:18 am
Location: Greece
Contact: YouTube

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

Fri Apr 16, 2021 12:12 pm

Why it is so risky to swap the plates to see what functions and what not? And yes I swap plates in TVs (Same model) to find the problem and it always worked! If I repair Succesful my charger I will post pictures ( here and on youtube ) of all the parts that ever have failed at those chargers so everyone can simply check these parts fast and easy and repair his charger! In other forums, some people found some other defective parts that will be integrated into my report!
If my logic is incorrect please advise me and tell me why? On the first side of this forums, links exist for fixes but My opinion is that it is no easy for a new guy here to spot his problem with his charger unless he has 2 blow high voltage capacitors or fauld precharge resistors!
I think I owe that to Mitsubishi ho build a charger that will fail in 8 or so years and sell only a new one for 4200 euro for a car that the price is now 6000euros. Also, they have no separate parts to sell you and no service for this charger! Is that no green Driving ??

Sandrosan
Posts: 31
Joined: Tue Sep 24, 2019 2:43 am
Location: Milan, Italy

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

Sat Apr 17, 2021 8:36 am

Hello everyone,
First of all let me congratulate with all the members of this forum specially with the active members!

I have a Peugeot iOn of 2012 where I have replaced 2 times the Pre-charging resistors of 4.7 ohm in a period of 9 months.
Now I have changed the resistors again, the AC input relay even if measuring it with a milliohmmeter with 10A test current the contact resistance was less than 10 milliohm, that for me it was OK. Once the relay was on my hand I opened it and the contacts were OK, clean. So I changed it for nothing...

Now I have been monitoring the charging current, the relay coil voltage, and the voltage across the 2x4.7 ohm resistors using a Power Quality Analyzer simultaneously.
I hope you can see the images here:
https://we.tl/t-C9pWeZmYKR

I have carried out just a few charge processes fully monitored. And in all of them I have noted that the relay coil voltage is always 5V but it has some instability / anomaly period too.
During that period it drops to 3.6V instead of 4.8 / 4.9V for several seconds also several minutes (in another survey even down to 2.6V!). Of course if the coil voltage drops too much, the relay will open and then the resistors blow....
I have tested another relay but same brand and model by my power supply, if the voltage drops down to 1.5-1.7 V it opens its contact, as its nominal voltage coil is 5V. I think that at 3V the force to close the contact will be lower than the normal and this can cause sparks and soon or later the resistors blow too.

The 5V for the relay and its return of come from the top board, and as I have another OBC, I tried swapping the top board including the flat cable, just to insulate the fault, but without success.

Has someone traced the part of the circuit that supplies the coil ? I guess there will be a transistor and some other basic component around it. But the top board works, so probably the problem is in another part.

Can the problem come from the circuits connected to the connector CN101, so from outside the OBC?

I have tested the voltages (5V, 5V, 12V , 16V) on the capacitors on the top board and looks OK (even no ripple) but I have not monitored them by the PQA over the time....

I think to use hot air and cold air to stress some components, but dangerous for the resistors...

Can someone give me any suggestion? Thanks in advance.
Sandrosan

Matheos
Posts: 22
Joined: Tue Jun 16, 2020 5:18 am
Location: Greece
Contact: YouTube

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

Sat Apr 17, 2021 12:59 pm

hallo, Sandrosan and welcome to the forum! I have not the solution for you but I have a question! How can you measure and tell that the resistors go bud? Are there visual black spots or so on the resistors or you measure them after you desoldering this big plate?

Sandrosan
Posts: 31
Joined: Tue Sep 24, 2019 2:43 am
Location: Milan, Italy

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

Sat Apr 17, 2021 1:43 pm

Matheos wrote:hallo, Sandrosan and welcome to the forum! I have not the solution for you but I have a question! How can you measure and tell that the resistors go bud? Are there visual black spots or so on the resistors or you measure them after you desoldering this big plate?


Hello Matheos,
In my case one resistor was visually burned with a black spot. So I gently destroied it without desoldering it and the big plate.
But you can test if the resistors are open or not checking the continuty (resistance) between the AC input with N mark (one of the two orange cable fixed by screws) and the output on the white jumper with faston.
Sandrosan

Matheos
Posts: 22
Joined: Tue Jun 16, 2020 5:18 am
Location: Greece
Contact: YouTube

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

Sun Apr 18, 2021 8:04 am

sandrosan, Sorry that I can not understand the meaning of <<<and the output on the white jumper with faston>>> Can you send me a picture with a mark of this faston clip ! You can directly send it to my email adress if you can not post it here! Thanks
matheos@gmx.net

Sandrosan
Posts: 31
Joined: Tue Sep 24, 2019 2:43 am
Location: Milan, Italy

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

Sun Apr 18, 2021 10:47 am

Matheos wrote:sandrosan, Sorry that I can not understand the meaning of <<<and the output on the white jumper with faston>>> Can you send me a picture with a mark of this faston clip ! You can directly send it to my email adress if you can not post it here! Thanks
matheos@gmx.net


Ok sorry. Pls ignore what I said before and refer to this photo: https://we.tl/t-acJhrnmhrr

Applying the tester on the two indicated points you should measure 4.7 + 4.7 = 9.4 ohm,

Matheos
Posts: 22
Joined: Tue Jun 16, 2020 5:18 am
Location: Greece
Contact: YouTube

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

Mon Apr 19, 2021 12:09 am

Thanks for the photo! I measure the points and found that I have not 9.4 ohms. So I gently destroy the resistors and found out that the big resistor has a thermal Fuse inside and this fall! These resistors must never put there from the beginning! They must be placed outside the charger because they get hot so after a while, maybe in 6 or 10 years or so, the thermal fuse inside the resistor will blow! I will search for a constraction to put the resistors outside the charger! First, they get better cooling and second if they fail it is easier to change them, also this heat that they produce will not more trap inside the charger! Thanks for your help !!! I advise you to do the same and maybe put resistors inside without thermal fuse! I found bigger and durable resistors on eBay :
search under:10/25/50W Watt Shell Power Aluminum Housed Case Wirewound Resistor 0.1-470 Ohm

Sandrosan
Posts: 31
Joined: Tue Sep 24, 2019 2:43 am
Location: Milan, Italy

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

Mon Apr 19, 2021 1:57 am

You are welcome Matheos, but I think these resistors blow only if there is something wrong, because I think they work just for few seconds on the precharging process of the 3 big capacitors.
Where are you from?

In my case I am monitoring why the 5v for the coil of AC input relay is unstable as I have written in my long post.
I hope someone has some advise.
Sandrosan

Matheos
Posts: 22
Joined: Tue Jun 16, 2020 5:18 am
Location: Greece
Contact: YouTube

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

Mon Apr 19, 2021 5:22 am

It is 50/50 !!! The resistors don t blow the thermal fuse in one of the resistors is triggered! From my experience, it happens sometimes without reason in some devices if the thermal fuse has continuous stress from heat! I will put them outside of the case because they produce heat and heat is stressful to all the components! I am from Greece! You? And also how can I put pictures in the forum, do you know?

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