trying to repair a mains charger for a Ryobi cordless drill

Thread Starter

Paul Mckenna

Joined Jul 25, 2016
2
I have this Ryobi cordless charger and it's just gone dead.

No lights show up on the charger (neither the green power light or red charging light).
I've took the cover off and traced the board for any signs of power. Although I did this with just an electrical screwdriver as i don't have a multimeter.

I have power virtually all over the circuit board, (so i don't know why the green power light isn't coming on).
anyway, I noticed that i have power going into what looks like a surface mount resister, but no power at the other end.
- is it safe to assume that this is where the problem is? - dry joint or a blown resister?
Should i have power coming out of this component if power is going in?
I don't know the value of the resister - it just says RX2. I also tried contacting Ryobi for a copy of the component list, but they don't respond.
 

tcmtech

Joined Nov 4, 2013
2,808
Buy a new one being you obviously don't have the knowledge, tools or the skills to fix this one.

How are you figuring out where power is by poking things with a screwdriver? o_O
 

Thread Starter

Paul Mckenna

Joined Jul 25, 2016
2
Buy a new one being you obviously don't have the knowledge, tools or the skills to fix this one.

How are you figuring out where power is by poking things with a screwdriver? o_O
I know how to solder, i was into electronics years ago, so i have some skills. I can borrow a soldering iron. If I can gain some knowledge on here, then i might be able to fix it. They cost £40 new, and that's quite expensive, especially if its fixable. I'm not going to poke just anywhere and don't intend shorting out any caps. I thought maybe it could be just a dry joint on the resister..?
 

bwilliams60

Joined Nov 18, 2012
1,183
As tmctech says, you are not equipped to repair this unit. If you do not have one of the most essential tools (multimeter), how can you ever find your way around an SMPS? You are dealing with some lethal voltages and should stop while you are ahead. If you are serious, buy some equipment and do some reading. And yes, you can use up substantial voltage through a resistor.
 

crutschow

Joined Mar 14, 2008
23,362
Trying to repair such an item is difficult, even for someone with good electronic experience.
You first step would be to completely trace out the circuit and create a schematic.
Without that we are basically guessing as to what might be wrong.
Then buy a cheap multimeter (or wait until Harbor Freight offers a free one) so the circuit can be trouble shot.
 

SLK001

Joined Nov 29, 2011
1,510
I noticed that i have power going into what looks like a surface mount resister, but no power at the other end. - is it safe to assume that this is where the problem is? - dry joint or a blown resister?
How do you know that the other end is not ground?

My point is just like everyone else's... beg, borrow or steal (or even purchase) a multimeter.
 

JoeJester

Joined Apr 26, 2005
4,077
Take a good picture of both sides of your PCB and post them. There might be some clues available for the members. Otherwise you would need to do as @crutschow suggested. If it gets to the "schematic drawing" stage, involving alot of circuit tracing, you will need to figure out IF the price of of new one is faster and less expensive then your time, energy, and effort is worth for you to effect repairs.
 

kirbz81

Joined Apr 9, 2017
1
I know how to solder, i was into electronics years ago, so i have some skills. I can borrow a soldering iron. If I can gain some knowledge on here, then i might be able to fix it. They cost £40 new, and that's quite expensive, especially if its fixable. I'm not going to poke just anywhere and don't intend shorting out any caps. I thought maybe it could be just a dry joint on the resister..?
did you fix the problem mate? I have same issue.is it just a case of changing internal fuse?
 
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