RYOBI-one charger

[simonmpoulton]

Re: RYOBI-one charger

sure model is BCL14181H and upon closer inspection of chip in question under the microscope i can make out the code 6853i34. I cannot seem to find any data sheet for this though!

[stj]

Re: RYOBI-one charger

no, SP6853
https://www.aliexpress.com/w/wholesa...rchText=sp6853

[R_J]

Re: RYOBI-one charger

sp6853 data sheet

[simonmpoulton]

Re: RYOBI-one charger

Ok yes that's it thanks but is there any compatible part code which is available from a UK supplier or is China the only option?

[stj]

Re: RYOBI-one charger

try Maplin?
lol

no, china is your only option.
or cheapest anyway, you may get it from germany(Reichelt), poland(TME) or the u.s.
i didnt check those sellers btw, i just know they have impressive range of stuff.

[simonmpoulton]

Re: RYOBI-one charger

Ordered from china so now the wait begins - a few of the resistors around it don't look great either do you know the values?

[stj]

Re: RYOBI-one charger

no, but you can usually read them even if burned.
check the ceramic caps too - incase of a shorted one.

[simonmpoulton]

Re: RYOBI-one charger

ok finally got my IC's from china unfortunately still no go - there appears to be a short on the output side of the transformer. All pins on the output of the transformer appear to be shorted to the negative battery terminal. I've checked and cannot see any obvious sources for this short - any pointers?

[R_J]

Re: RYOBI-one charger

Yes, one end of the transformer is connected to ground, the other end of the winding should go to a diode, then to a capacitor, and eventually to the output
If you measure the DC resistance on the transformer pins The winding itself will be very low, lees than 1Ω
Check the resistance of R2, R3, R4, R7, R8 & R9 and the large grey resistor between the transformer and fet
EC2 cap may also need replacing
You did install the ic the right way?
Using the large main capacitor's negative as ground, check the voltages on the ic, carefull don't slip with the probe.

Also when you said the mosfet blew up did you mean the one in the primary or Q2 in the secondary?

[stj]

Re: RYOBI-one charger

re-read the whole thread and check the smd fet and the big schottky diodes.

[simonmpoulton]

Re: RYOBI-one charger

IC Installed correct way yes - I will check the resistances of the resistors mentioned later and report back. I'll also attempt to check the input voltages on the IC

As for a recap on the original issue - main SMD fet on the secondary part was burned due to the short of one of the diodes as per original thread post. I have replaced already the main smd fet and the twin diodes as per the original thread post. Also have replaced the protection Zener on that circuit. All electrolytic caps have also been replaced. It was still no go at this point so I started investigating the issues elsewhere and found IC1 burned which is now where i'm at.

[stj]

Re: RYOBI-one charger

shorted ceramic cap is possible.

[simonmpoulton]

Re: RYOBI-one charger

Ok so R2, R3, R4 were all burned - R2 very badly - had a hole in it. D1 was also burned. All replaced, The grey resistor RS1 was also burned with a hole in it. I have replaced RS1 with a 0.4Ohm Resistor - it shows as a 0.43Ohm resistor but 0.4Ohm is the closest I can find - is this likely to be an issue? I don't want to plug this in if that's going to burn something out!

Also BD3 was shorted - this one is a diode between what appears to be the primary side ground and mains voltage input - would probably explain why RS1 and R4 burned so badly as they would've received mains voltage! - Do you know of a better replacement for BD3 or should I look for a like for like replacement?

As for the ceramic caps - i've checked quite extensively around and none appear to be shorted

[R_J]

Re: RYOBI-one charger

D1, R3, R4 are between the ic output and fet gate. When the fet Drain shorted to its gate it will supply full B+ to the gate circuit and IC ! they don't like that. R2 is the current sense feedback from the source resistor of the main fet to the ic. If the fet drain was also shorted to the source, R2 would blow. There is also a green resistor between the fet Source pin and ground, Or is that RS1? there are two of these similar resistors, that source resistor and one that goes between B+ and snubber circuit of the fet (connected to RF2 10Ω resistor)

Your pictures are too out of focus to make out BD3 But it is likely one of the four that make up the bridge. I would replace all four with what was there, they are not that critical.

[stj]

Re: RYOBI-one charger

for the mains bridge, if 1A is enough then use 1n4007
what is the original part?