Help! - Need IC part number for Handy 2 charger

[mferri]

While charging, I recently had a roof leak drip onto the charger . A chip inside the charger (Bantam Technology Handy 2) fried, but it looks like it could be the only part that needs to be replaced. You can't make out the ICs part number due to the charred condition of it. Can anyone reply with the ICs part number (markings should do). It's the 8-pin SOIC that's right at the input supply on the PCA, right between the negative lead and the proximal screw/hole.

It's really easy to get access to the IC markings - only a few screws (then a reply). Thanks in advance for any help. Feel free to e-mail me at mjferri123@yahoo.com.

Special thanks to Hall Woo for pointing me to this forum!

[mferri]

It looks like it's for reverse voltage protection. There's a similar IC on the output that's a Fairchild semiconductor FDS4410. It's likely that the burnt IC on the input is the same. Hoping to hear back from Bantam Inc. They don't make the Handy-2. The replacement charger is Bantam's e-station 301DX. If anyone has this charger and has a few minutes to check the IC's part number for me, it would be greatly appreciated.

Thanks in advance.

[jeffs555]

If you can't find out from the manufacturer, you could check the wiring on the board. If it was a FDS4410(an N channel mosfet) then pins 1,2,3 would be connected together and pins 5,6,7,8 would be tied together. Pins 1,2,3 would most likely be connected to ground. If pins 1,2,3 are connected to positive, then is is probably a P channel mosfet.

If it is as you suspect reverse voltage protection for the input, this page describes how it works. http://www.geofex.com/Article_Folders/mosswitch/mosswitch.htm
This shows a P-channel inserted into the positive input. If yours used an N-channel, it would be inserted into the negative input.

[mferri]

Thanks Jeff. It's configured like the FDS4410 and FDS4410A datasheets, and your article show (source pins 1-3 tied to board ground, and drain pins 5-8 to the negative input lead - adjusting for any bias shifts from the negative voltage referenced). It's exactly the way the FDS4410 on the output end of the charger is configured as well.

I tried jumpering across the device (source to drain), but the charger still doesn't work. There's probably more wrong with it than I'm willing to uncover.

The reference article you sent the link for is terrific.

Thanks for being so helpful AND resourceful.

Michael