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Old 23rd Apr 2023, 1:59 pm   #21
Sparks
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Default Re: Kenwood battery charger - repairable or worth repairing?

Some more pictures as promised although I don't think they show us much more. The limitations of a tablet camera! The grey wire and middle charging definitely haven't been connected or soldered. I had a good luck with an illuminated loupe.
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Old 23rd Apr 2023, 2:16 pm   #22
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Default Re: Kenwood battery charger - repairable or worth repairing?

The soldering on the socket connectors does look a bit ropey. I'd certainly reflow it before digging any deeper. Obviously try not to melt the plastic.

Just to confirm, this charger used to work but has stopped, yes? It's not that it's never worked?
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Old 23rd Apr 2023, 2:26 pm   #23
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Default Re: Kenwood battery charger - repairable or worth repairing?

It worked perfectly until the time of my original post!
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Old 23rd Apr 2023, 2:30 pm   #24
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Default Re: Kenwood battery charger - repairable or worth repairing?

There is also a possible intermittent short between the top socket pad and the adjacent track.
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Old 24th Apr 2023, 8:29 am   #25
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Default Re: Kenwood battery charger - repairable or worth repairing?

Thankyou Paul.
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Old 24th Apr 2023, 1:36 pm   #26
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Default Re: Kenwood battery charger - repairable or worth repairing?

I've tried reflowing the solder joints on the power input socket - no change. Likewise, connecting the mystery grey wire to the middle charging terminal hasn't helped. I'd be grateful for further suggestions. Thankyou.
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Old 24th Apr 2023, 1:47 pm   #27
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Default Re: Kenwood battery charger - repairable or worth repairing?

We have a much better view than before but in the top side shot the numbers on the ICs are still obscured by the wiring ascending from the PCB.

Could you read the chip numbers off both of those ICs, stating which is which?

I can't read anything of note from IC1 which is positioned vertically in your shot, the horizontal IC, IC2(?), appears to be made by ST (SGS-Thompson?) as it has their badge on it, but I can't see any further detail on that one either, in both cases because there are wires in the way.
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Old 24th Apr 2023, 1:58 pm   #28
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Default Re: Kenwood battery charger - repairable or worth repairing?

Do I see a ring shaped crack around one of the solder joints (indicated by a red ring, attached)? That looks to be one of the legs of the rather wonky looking 100K resistor, try wobbling that part gently back and forth while looking at that solder joint to see if it moves, or brute force method, just resolder it.
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Old 24th Apr 2023, 2:13 pm   #29
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Default Re: Kenwood battery charger - repairable or worth repairing?

The horizontal chip is an ST LM324.
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Old 24th Apr 2023, 2:22 pm   #30
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Default Re: Kenwood battery charger - repairable or worth repairing?

Thanks DS, that isn't readable on the screen I am using here - that's one common or garden quad op-amp, now we just need to know what the other IC is. I can see what looks like it may be part of the Microchip logo which would make it likely to be a PIC microcontroller, but I may be barking up the wrong tree.
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Old 24th Apr 2023, 2:40 pm   #31
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Default Re: Kenwood battery charger - repairable or worth repairing?

The charging dock has three contacts, as does the LiOn battery pack.

The central contact in dock and on the battery pack both have a purpose in life, as does the grey wire, which presently has no home. Logic dictates that the central wire has most likely come adrift from the central contact. You believe that the charger is most likely a KSC17. It will be similar, but not identical to the KSC35, the manual for which you can download at this link:

https://www.manualslib.com/download/...d-Ksc-35s.html

If you look at that circuit, you will see that it has three terminals in the battery cradle, one marked B+, one B- and the other T1.

I can only reiterate what I said in post #17, that however unlikely it might seem to some, the only explanation to my mind, is that when the charger was dropped, it most likely fractured the stranded grey wire from the central contact, strands of the wire having been cut through when the insulation was stripped back at the factory. How can a battery pack with three contacts be charged from a charger in which only two of its three mating contacts connected to the PCB? Or so it seems to me.

(the other two contacts look poorly soldered and I'd be inclined to remake them, stripping back the insulation to my own satisfaction).

Good luck with it anyway.
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Old 24th Apr 2023, 4:21 pm   #32
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Default Re: Kenwood battery charger - repairable or worth repairing?

Easy David. The charger just doesn't monitor the temperature sensor in the battery - that's how most cheap LiIon chargers work. I agree the loose wire is puzzling though.
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Old 24th Apr 2023, 7:03 pm   #33
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Default Re: Kenwood battery charger - repairable or worth repairing?

There are a couple more joints which look to have signs of a crack and another pair that just look messy. See the attached image.

Paula
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Old 24th Apr 2023, 8:08 pm   #34
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Default Re: Kenwood battery charger - repairable or worth repairing?

Maybe it's a good idea to reflow *all* the joints. It should only take a few minutes.
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Old 25th Apr 2023, 7:31 am   #35
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Default Re: Kenwood battery charger - repairable or worth repairing?

Much obliged again, everyone. It will be at least the weekend before I can have another look.
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Old 9th May 2023, 4:46 am   #36
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Default Re: Kenwood battery charger - repairable or worth repairing?

I've not forgotten about this! It just keeps finding itself on the bottom of the pile.
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