I got refund for my broken c4-12 upgrade so now there is time and budget to open it.
After some measurements that I’m capable to do it looks like @tantien11 has right in my case.
Drain (LX) of second slot ME3118A gives full 12V and that gives overall error on this slot.
Attached picture that expose names of particular parts, not especially pretty but you should get part name.
I’m talking about 4 sop8 ICs placed on top - in my case it is second from left.
That was my first dispute on AliEx but there was no chance for full refund they first offered 1/4 of price and after that weirdly offered 55% without returning device.
Anyway it seems to me this IC is simply faulty and with my knowledge of several internet parts shop not found any decent repacement so ordered 5 pieces from ebay.
Whole crash probably happened when my protected 18650 was in #2 slot, that was my first attempt of loading of anything to this charger.
Only saw screen get reset and after that only error was displayed on #2 slot no mater what was putted there.
I have friend here who has hot air station and is capable to replace this IC - like said before it can be tricky to replace it only with soldering iron because of LX drain PFET pad that is placed under sop8 package. I don’t want to risk doing this myself
You described how the error happened — I was also charging several 18650s on the C4-12 (I was near the charger since I was still observing this new charger), then the screen reset, and slot #2 showed Error.
If you’re able to open it, can I ask to take a picture of what parts are needed to be replaced? Thanks!
I don’t have the skill or knowledge to replace, but in case I can find someone who may be able to do it…
I bought a second miboxer c4-12 and swear to not buying anything from Miboxer anymore.
Their customer support is non existant, their reply contact the seller for a refund, we dont care that we made a faulty device and not going to do anything about it.
My first “upgraded c4-12” (the same one with two buttons) does not charge the batteries properly, stopping way too early and has display artifacts errors (basically the numbers get out of bounds and it displays gibberish and that would explain why it terminates too soon).
This was a V2 model.
I reported this to Miboxer customer support and got the usual response contact the seller for a refund we dont care attitude.
Contacted the seller and got a full refund and got to keep it but unless someone would know how to fix it its useless.
A few months have passed and I thought that they would have a new version of this model and I really like the features of it so I ordered a new one.
Got it and its V2.2 so I was excited to use it.
Put it a bunch of old cells that I have and quickly realized that this charger also doesnt work.
First it starts charging at 300mA and not 100mA like the older one.
Thats fine but a few minutes in it crashes completely (it looks like it gets stuck in some sort of loop because it just keeps switching thru the slots) and stops charging.
It also doesnt display FULL when its finished (I assume its finished because it says 100% and the current is 0)
Again I reported this to miboxer with video and got the same response as the previous one.
Contacted the seller to get a refund but this time I have to return the unit.
Mine manual is branded with V2 in the lower right corner so i thing we are talking about it.
Since you are returning it, you cant relay look inside to spot differences but according to your issue with it, it is going worse.
When opened mine for repairs - there is no any sign of quality check or something like that, maybe this is their weakness.
I didnt open mine so I dont know what it looks like inside.
Miboxer told me that the fact that it didnt show the word ‘FULL’ when the cell was charged that it was faulty and to return it.
Have you noticed that with your V2 especially with NIMH that it doesnt really charge up to 1.50V? On my V2 it usually stops at around 1.38V.
Also it gets messed up with the IR numbers and just shows gibberish instead of numbers.
Looked especially for low voltage finish since several people here said it could be a problem, but no, mine (including slot #2 with reworked IC) charges same on all slots for example four new eneloops finish at 1.52V 0.75A 0.51-0.55mohm.When measured right after eject with multimeter it shows 1.49V. No garbage readings.
forced to replace second chip, this time on #1 slot same symptoms, same resolution, fortunately i have still 3 spare parts.
Anyway, beside this charger work great when not broken, I’m not recommending miboxer c4-12 upgrade to any end user not familiar with hot air smd montage.
Did not get notification for this so it is one year old - @Sidney Stratton did you tried replacement ?
I think you already now that ME 3118A are located horizontally (almost inline) with hugest capacitor on board.