Whats wrong with my ARC-LS Driver?

Hello everyone, I am having a problem with my ARC-LS driver board. it was working fine before i took out the old emitter and installed a Seoul.

whats happening is the LED would blink just once and then turns off. the thing that is circled red gets hot very quickly when I connect the battery. Now get this, when I remove the LED and connect the battery, it still gets hot. Anyone have any ideas whats wrong? I'd really appreciate any help/suggestions.

That's the IC. Did you bridge any of the solder spots during surgery?

I don't know if that IC can take an open load; it might

Hi CPFU,

When installing the P4, was the slug isolated using thermal epoxy? Unlike the Luxeon it was replacing, the P4's slug is not neutral and must not make direct contact with the flashlight's ground path - the aluminum LS board.

Removing the LED and applying power caused an open load situation. Sorry to be the messenger of bad news, but the black square marked LTNH is the DC-DC converter and is now dead.

The good news is that replacements are available through Digikey for a few dollars each, don't have the part number handy but maybe someone will chime in. You also have a few DIY modding options available, there's a bunch of LS threads in this sub-forum.

Best of luck!

Derek

Yikes! Well, I guess I can chalk one up for the learning experience.

Any ideas where I can just buy a replacement board that will just "drop" in?

that DC-DC converter is tiny and it'll be pretty hard for me to replace.

Thanks to all you guys helping me out.

Good luck finding a replacement board. I think they're getting rare - not impossible, but rare. Doesn't hurt to try B/S/T. Or you can design a whole different board mod.

My notes say the integrated circuit chip is from Linear Technology and is a model LT1618EMS DC-DC converter, should you decide it faster to try replacing it. I think Digikey has them. Maybe you can find a friend with surface mount soldering equipment.

thank you all for your replies. I went to digi-key but not sure which one I need. I ran a search and found several. I think its the one below but I'm note sure.

Digi-Key Part NumberLT1618EMS-NDPrice Break
1
25
100Unit Price
3.50000
2.08000
1.86000Price
3.50
52.00
186.00 Manufacturer Part NumberLT1618EMS DescriptionIC DC/DC CONV STEP-UP 10-MSOP

also, part numbers that came up are:
LT1618EMS#PBF
LT1618EMS#TRPBF
LT1618EMS
LT1618EMS#TR


thanks in advance.