Parkside PLG 20 A1 4.5A Battery Charger fix

[Pixa]

Hi all,
i'm new here, and i'm a beginner in electronic circuits, i have a little previous knowledge from electronics high school, but nothing serious enough.
I have an PARKSIDE PLG 20 A1 4.5A charger which just stopped working. I have bought a new one, but i would like to see if i could fix this one, as some little fun side project.
Unfortunately, my knowledge is to thin, so i'm asking you for help.
I did some basic troubleshooting with multimeter, and the voltage that is coming to the primary transformer coil is not constant (to be honest i don't know if it shuld be or no), and there is cricketing sound comming from one of the components, not sure which.
Now i'm stuck... Do you maybe have some suggestions, what to troubleshoot ?
Thank you all in advance...

 

[Delta Prime]

This is not your particular unit but the process is the same apologies if you have you already seen this.

 

[Pixa]

Hi,
Yes i have seen it, but in my case the optocoupler is ok, and the transistor seems ok, both tested with multimeter (eventually if I need to desolder it to test?)

 

[Delta Prime]

Yes desolder it to test

 

[Harald Kapp]

if I need to desolder it to test?

You'll have to. Testing components in-circuit is tricky at best, gives completely wrong indications at worst. This is because other componnets in the circuit and the wiring influence your measurements.

 

[Pixa]

Hi,
i have desolder the mosfet transistor, and it works fine, i even created small circuit to test it like this

 

[Delta Prime]

Okay I believe you well done!

You say you bought a new one did you do a comparison? Voltage resistance that sort of thing

 

[Delta Prime]

You know what I haven't even bothered to look at your photos apologies give me a second

 

[Pixa]

Okay I believe you well done!

You say you bought a new one did you do a comparison? Voltage resistance that sort of thing

Yeah, the new model is not exactly the same. And to be honest i didn't want to mess with the new one

 

[Delta Prime]

Underside of the board surface mount components take a look at D1 it doesn't even look soldered visual inspection on your end. Check with the multimeter ,no need to take another photo

 

[Delta Prime]

Did you happen to check the fuse (F1) 3.15 amp/ 250 volt continuity check with multimeter.
I don't blame you.
I'm download your photos make some comments on the photos themselves circles and arrows and stuff like that.

 

[Delta Prime]

PARKSIDE PLG 20 A1 4.5A

Why would it have a 3.15 amp fuse on a 4.5 amp charger?
I think the assembly line stuck in the wrong board.
And there's a lot of solder splatter on the solder side where the surface mount components are I would check your new one to at least do a visual check for solder splatter just clean it with alcohol 99%
I'll be back

 

[Harald Kapp]

Why would it have a 3.15 amp fuse on a 4.5 amp charger?
I think the assembly line stuck in the wrong board.

I think you need to re-think and check facts first: the 3.15 A fuse I'd expect to be on the primary side whereas the 4.5 A rating is for the low-voltage seondary side. So all is good here.

 

[Pixa]

I soldered back the mosfet, and checked D1 as you suggested. So, the continuity test (the diode sign on multimeter) shows around 700 from one side and OL on the other, which is as it should (i think). But when i plugged the charger in AC, i tried to test the voltage across D1, and it was unstable, it fluctuated from 0 - 600V DC

 

[Delta Prime]

I think you need to re-think and check facts first:

No need that's what you're here extra pair of eyes are always good thank you for the information.

 

[Delta Prime]

Are the ones circle you have to visually check I see solder blobs even the components they look fake actually. I would seriously consider opening your new one up and see if it looks this board.

 

[Delta Prime]

I soldered back the mosfet, and checked D1 as you suggested. So, the continuity test (the diode sign on multimeter) shows around 700 from one side and OL on the other, which is as it should (i think). But when i plugged the charger in AC, i tried to test the voltage across D1, and it was unstable, it fluctuated from 0 - 600V DC

Diode check without power was sufficient enough. As for the fluctuation it's supposed to it's a high frequency transformer. Without power and for safety reasons discharge those capacitors if you got like a 5 w resistor hundred ohm put some alligator clips on it and and connected across those big cap or that one big cap or all of them. Before you start probing around or soldering anything

 

[Pixa]

Thanks, i was aware of the discharge, no worries.

 

[Delta Prime]

Where did that other guy go. I think we should ask him,heel probably fix you right up.
It's going to take a while with me.

 

[Delta Prime]

In any event I believe you got some work to do.... and try to clean that board up. I need to go to ruffle some other feathers.