Arc LS Converter Repair - Please Help

[darkzero]

Electronics gurus, please help.

I have an Arc LS that outputs very dim. It's not the Luxeon cause I've applied power directly to it & it light up fine.

I noticed the inductor has a chip on it but there's still continuity so I'm assuming it's still good? Or could that be the problem?

The cap is not open & neither is the resistor. I thought the black thing by the cap was a diode but I get fluctuating continuity both ways. What is this?

What should I check for? Is there a way I can check the IC?

The components look very similar to the non-Nexgen Badboys. I was thinking about swapping components over from one.

Appreciate any help. TIA.

 

[Probedude]

Even with the chipped inductor you should be getting better output.
That diode is a diode. You're probably getting continuity both ways because it's still 'in circuit'.

Measure the resistance of the green resistor, it's marked R15 for 0.15 ohms. It may have gone high. This sets your output current.

 

[louie]

I'm no expert, but my notes say:

Wayne at the Shoppe designed it. You might try asking him.

The black thing by the capacitor is a Schottky diode 1N5819HW from Diodes, Inc. Your continuity readings can be misleading, either from insufficient test current to turn the diode on in the forward conductance mode, or by being in circuit. That's what diode test modes in DMMs are for.

The IC is Linear Technology LT1618. I hear they die if the board is turned on with no LED attached. Just replace it. I think Digikey has them.

IMO, unlikely that the inductor chip shown would kill it, or that the resistor would change.

 

[darkzero]

I'm no expert, but my notes say:

Wayne at the Shoppe designed it. You might try asking him.

The black thing by the capacitor is a Schottky diode 1N5819HW from Diodes, Inc. Your continuity readings can be misleading, either from insufficient test current to turn the diode on in the forward conductance mode, or by being in circuit. That's what diode test modes in DMMs are for.

The IC is Linear Technology LT1618. I hear they die if the board is turned on with no LED attached. Just replace it. I think Digikey has them.

IMO, unlikely that the inductor chip shown would kill it, or that the resistor would change.

That makes sense, no wonder they look so similar in design to the Badboy.

After some heavy digging I found a post by Wayne stating a broken inductor like the one I have can very much be an issue.

I went ahead & ordered some of the ICs from Linear Technology & some coils from Coilcraft.

I'll post my results here after swapping out the components.

Thank you! :thumbsup:

 

[louie]

OK, makes sense.

My notes say the L is a Coilcraft DO1608C-332 (3.3uH)

 

[ZuluWhiskeyFox]

A couple of years ago I had exactly the same problem and posted a similar thread to this one. My inductor coil was chipped exactly as yours appears. I had no luck getting a coil. Until I contacted Wayne at the Shoppe. He supplied me with a coil and that was indeed my problem. Board worked great after that. I suggest start with replacing the coil.

cheers,

zwf

 

[darkzero]

A couple of years ago I had exactly the same problem and posted a similar thread to this one. My inductor coil was chipped exactly as yours appears. I had no luck getting a coil. Until I contacted Wayne at the Shoppe. He supplied me with a coil and that was indeed my problem. Board worked great after that. I suggest start with replacing the coil.

cheers,

zwf

I ordered the same coils Wayne listed in your thread you're talking about directly from Coilcraft. They were $0.76 ea. Thanks