Why doesn't my charger work?

Seems to be a thing with these chargers. This is what I have failed on this one:

R2 (470 ohm), R3 (220 ohm), R4 (150 ohm), RS1 (0.43 ohm) - all open circuit

Q1 (NDF04N60ZG) - shorted

IC3 (SG6848) - probably blown

The above components are PWM control and the main chopper transistor on the primary side. Normally a blown chopper will take out the main fuse, but there isn’t even one in this design. Instead they rely on RS1 (fusible resistor I’m assuming) to go open when the chopper shorts. This is a really crappy design, since the main filter caps would be a at 400V DC in the fault condition. There’s no bleeder resistor incorporated either, so if you go working on this, make sure you discharge the cap.

D3/D9 (SB5200) - one shorted, other ok. These are the main rectifiers on the secondary side. I’ve seen this go short in other supplies, but good designed ones will shut down the PWM to prevent damage. Not this one it seems.

Q2 (9565BGH) - Shorted (in fact had a hole in it).

Q4 only reads 0.6V on two pins, but I suspect this is actually a zener diode in a SOT346 package. Only see 202 or 702 on the package. Be nice if I had a schematic.

Just an awful design as far as switch modes go. Haven’t seen this much destruction since the old days of self oscillating supplies. Anything with a PWM IC usually has over current/voltage protection to shut everything down. Just a poorly designed and CHEAP supply. I was half through repairing it and I’ve now decided to bin it. It’ll only blow up again.

I have the same problem just different part.

Can someone tell me markings of this chip (IC1)?

Thank you!

Hello

This 2x3 pins IC is : 6853H37

Hope this will help

same problem after you fit the new one glue a small piece of alli or something like that as a heatsink.

Where can you buy this part 6853H37 . I have the same problem with my charger but I can't found this part or a datasheet is also nice .

Thanks for help .

Mosfet 9565BGH = Mosfet FDD4685

Hello,

My Ryobi Charger Board has problem as below:

- The Diode MBR5200 was short circuit

- The Mosfet Mosfet 9565bgh was burned

- The Zener Diode ZD2 which is closed the Mosfet 9565bgh was burned.

I have replaced the Diode MBR5200 and the Mosfet 9565bgh, but I did not know what is the Zener Diode ZD2 (Regulated Voltage = ?)

Please advise with thanks,

Anh Le

Can someone tell me markings of the IC3?

Where does the 9565BGH get it’s gate from? My continuity check reveals to be connected to only ZD2 and R11.

• EDIT ***

After some more exploring I have found out that the gate is driven by R12 and Q4. When the 9565BGH blew it must have damaged the copper trace between the gate, ZD2 and R11. To make it work again I had to replace the mosfet, ZD2 and the two MBR5200 schottky diodes ( one was short ciruited and I did not want to take any chance with not replacing the second one) and re-trace from R11 to the gate of the mosfet. I have added the circuit from a small part of the reverse enginered circuitboard. Hope this helps someone.

Hello,

Can someone tell me the voltage of ZD1 please?

Thank you in advance

Hey,

I think I have a similar problem, mine seems to have burnt out and potentially some of the parts around it. I've attached a photo, could I please ask your help to identify the parts.

The main part I need is AP9565BGH I believe

Thank you!

I replaced many parts described by posters here. Worked for a couple goes. Today all seemed normal with flashing green light but doesn't progress with charge. Hmmm. Battery tech sux.

Hi guys, can I put any MOS FET

It depends on the output power if positive p channel if negative n channel and also depends on the voltage and current of the circuit board.

Hope this help.