Parkside PLG 20 A1 4.5A Battery Charger fix

[Pixa]

So I did some research, that zener diode (zd1) is definitely faulty, but the problem is that I don't know what is her reverse voltage value. Does anyone maybe have some idea?

 

[Pixa]

BTW, I have also opened the new charger, and it is completely different than the faulty one...

 

[Delta Prime]

diode (zd1) is definitely faulty

I can't see from the photo any markings on it numbers letters or is it burnt to a crisp

 

[Delta Prime]

Stand by I got an idea!

 

[Delta Prime]

The schematic below is switch mode power supply from another thread. Because of your responses I believe this paints a picture for you that needs no explanation. But notice on the secondary side the 12 volt 2 amp output and scroll down to that led
That is your opto coupler or could be, if we're lucky do resistance check, we're trying to follow the path from the zener
Cathode to LED cathode of your optic coupler it may be resistance in between ,configuration may be different,see if they are connected with your meter. Also the zener diode is rated at 11:00 volts DC and the output of the transformer is 12 volt DC therefore the value of the zener diode would be one volt less than the output to charge your battery. This is an educated guess. But it wouldn't hurt you're very proficient at research so I suggest you do so... and report back. That's my idea! No offense but this configuration is common on cheapo (inexpensive) chargers. Could you taking another photo of that board the solder side I will be criticizing your work but it will be constructive criticism. Maybe a couple jokes in there.

 

[kellys_eye]

D1 is, in my opinion, the 'flyback rectifier' and not a zener. Measure the DC across the bridge rectifier (+ and - terminals) for around 310V DC (steady, assuming a 230V AC input?).

If you have a steady voltage at the bridge rectifier (same at the +/- terminals of that big smoothing capacitor) then the most liekly suspect - without delving into too much fault-finding - is likely to be the device on the heatsink and covered in silicone gunk - this is the main switching device and/or integrated switching controller. You'll need to desolder that to test and/or replace. If it's a simple MOSFET then testing will suffice but if it's an integral switching controller you need to replace it.

After that then IC1 could be suspect.

TBH I'd be looking for the DC OUTPUT of the secondary and, with no AC on the input, inject the equivalent DC from a power supply and see if the actual charge/control side of the secondary is performing properly i.e. does it do what it's supposed to do?

The largest capacitor on the secondary side would normally have the DC across it (from D6 and D7) and the resistors R21A,B and C monitor charge current for fault conditions (I'm assuming your battery is actually ok?).

Keep away from the high voltage side (leave it unpowered) until you're certain the secondary charging control circuitry is working.

 

[Delta Prime]

D1 is, in my opinion, the 'flyback rectifier' and not a zener

Everyone's entitled to their opinion.
You sure you got the right thread?
"You see the red circles"
Blah blah blah blah blah.
They all look pretty bad
The TS tested zener.
It is labeled on the PCB silk screen as ZD1.
I'll give you a hint at this location it's circled in red! Where's Waldo?

 

[kellys_eye]

take a look at D1 it doesn't even look soldered visual inspection on your end.

My bold, your quote....

 

[Delta Prime]

My bold

But not as bold as I.
But don't quote me on this.
Your explanation has merit
Unlike myself you definitely know what you're talking about.

 

[sansan]

i have same problem... Two identical charger: one charge the battery, other blinking red and green... The good one is not mine :-|