Help! Imax b6 charging issues

[Nunki0]

Hello,
I've had this charger for a few months now and it has always worked perfectly. Once, I tried to power it from a 3s liion at about 12.2V. I'm pretty sure that I did not reversed the polarity, but anyway there was a big spark when I plugged in the liion and some smoke went out. After that, the charger would still power up with its power supply but once il start to charge something, the screen would slowly turn off and the charger would reset with a puff of smoke. I opened it up, but I couldn't see anything looking burnt whatsoever. I never located the origin of the smoke because now when I try to charge it says that the connection is broken, even though I'm absolutely sure it is not. That's all I know, and I'm not good enough in electronics to know what to test.

 

[danskis]

I'm not an electronics expert or even a beginner but I've released enough "magic smoke" to know that once you do that you're screwed. That thing is probably trash. Sorry to deliver the bad news.

 

[Shurik-1960]

Do not despair and throw away anything. The IMAX B6 is very easy to repair. Here is a replacement card that shows the names of the electronic components. If you do not understand and do not know how to solder, just print out the card and take it to the phone repair technician.He will simply change the elements and your charging will start working again. I have repaired more than 20 such chargers for aircraft modelers for free. Basically, it is a replacement for :IRF7413, IRF7416, L7805CV .I always change these 3 elements together!!!!

 

[Nunki0]

Hi,
Thanks @Shurik-1960, I will try to follow this.
I finally found something that looks burnt: the NCE4435 power mosfet near the power plug. I'ill join a picture. I have similar looking components in some scrap electronics, but I'm not sure if it is compatible...

 

[danskis]

Glad you have the skills to repair it. BTW I did a google search on how to repair it and there is a ton of stuff. Try looking at the stuff on RCGroups.

 

[Shurik-1960]

NCE4435 is a voltage regulator and costs pennies on Aliexpress.com . I buy all the radio components there when it is possible to wait 15-25 days for delivery..

https://aliexpress.ru/item/1005005838961683.html?sku_id=12000034531755311&spm=a2g2w.productlist.search_results.0.5e8b1f13jVbC4N

 

[Nunki0]

Glad you have the skills to repair it. BTW I did a google search on how to repair it and there is a ton of stuff. Try looking at the stuff on RCGroups.

I've looked there already, but it wasn't exactly the same symptoms. But I'll look again.

Thanks a lot for all your help. There is a electronics store near where I live, maybe I can find replacement chips there. Otherwise, I'll buy from Aliexpress. I'll post a message when it is done.

 

[Shurik-1960]

If you want to use the charger happily ever after , then when ordering on aliexpress.com order all 7 transistors shown in the diagram : they are sold in several pieces, you can profitably sell extra parts by forming a charging repair kit. The only thing I forgot to specify is that it is necessary to view ALL the thin tracks on the board with a large magnifying glass, especially on the long side.Very often, a thin track burns out during short circuits and overshooting ( near the buttons )Once you repair your charger, you will become an expert at repairing these chargers.

 

[Shurik-1960]

Last week, my friend, a modeler from Lipetsk, burned the charger and I sent him a repair kit (7 transistors that I wrote about according to the scheme).He took it to the phone repairman, who changed it on the board. The charging started working. Anyone who has a repair kit and the ability to solder can repair this charger.

 

[Shurik-1960]

Today I was presented with a faulty charger.Tomorrow I will open it and decide on the treatment and put up a photo. This is HK charging. I'm going to finish it -I'm putting in a cooling fan, after the repair. There are no unnecessary charges)))

 

[Bricks]

A little thing I learned in a pinch for desoldering wick as I ran out is make your own. Simple small multiple strand copper wire strip the insulation twist together the copper strands and flatten cover with flux before desoldering. Have never bought wicking since.

 

[Shurik-1960]

The whole troubleshooting along with disassembly took 5 minutes. The scheme and elements are very similar to Imax B6. 1.After connecting the board to the power supply, I check all the elements for heating with my finger. In the left area of the board, I almost got a burn in the area of small transistors..2. I take thermal paper for fax (or a simple receipt from the store) and press it to the place of heating 3. I easily find the heating element by the dark point of the print. 4. Soldered a faulty transistor and soldered a new one according to the scheme. 5. Connected the power supply and checked the heated one with my finger 6. Connected the battery - everything is charging and discharging. The repair is finished. The next step is to find a place for the fan and supply power to it.Have a good repair to everyone.

 

[Shurik-1960]

I charged 3 batteries today. Charging works great.