EH Metal Muff

[PhiloB]

Picked up a Metal Muff with Top Boost on CL listed as broken for $5.  Won't power up.  Figured it was a blown voltage protection diode.  Opened it up and it is SMD!  Should have known.  What's a rough estimate in terms of money investment for equipment for getting started on SMD?

[PhiloB]

After some searching, it seems possible that a regular soldering iron might suffice in removing the diode and replacing it.  Anyone with any experience in this area?

[rullywowr]

Investment about $3 - a pair of smd tweezers. Cut the old leads off the part and solder another in there.   A smd hot air tool is nice but you can just use your ref iron.  If you want to unload the muff I'd be interested.

[PhiloB]

Thanks Rullywowr. The diode seems to lay flat against the board.  Not sure how you would cut the lead.  Would you use an exacto knife or something?
I'll let you know if I decide to be rid of it.  It seems to be in good condition mechanically and cosmetically. 

[rullywowr]

No problem. Since the diode is fried anyway just cut it right in the middle. Use your iron and some wick to clean the pads and install a new one

[PhiloB]

Here is a pic.  I'm assuming D2 would be the correct diode given it's proximity to the power jack.  Need to verify with a schematic.

[rullywowr]

It would appear so. Can you test it with a dmm?

[PhiloB]

I can later tonight.  I'm just learning but if it were that diode, I would find voltage on one side and not the other?

[rullywowr]

If the diode was to blame yes you would find 9v on one side but not the other when plugged in. Try both ways. Most likely was used with wrong adapter and burnt out. 

[PhiloB]

That's my hope:)

[Govmnt_Lacky]

Im a little new to SMD parts but....

That component marked D2 in your pic looks like a transistor to me. Do they make diodes in that packaging?

Also, as an alternative... could you peel up the D2 part and replace it with a through hole diode using the solder pads right next to it?

EDIT: Looking up the code 104H tells me that it is a 100uH INDUCTOR. Might want to research it before you go pulling parts 

[PhiloB]

Guess I need to find a schematic.  Did a quick search on my phone an came up with nothing.

[rullywowr]

Im a little new to SMD parts but....

That component marked D2 in your pic looks like a transistor to me. Do they make diodes in that packaging?

Also, as an alternative... could you peel up the D2 part and replace it with a through hole diode using the solder pads right next to it?

EDIT: Looking up the code 104H tells me that it is a 100uH INDUCTOR. Might want to research it before you go pulling parts 

Diodes often come in sot23 and melf packages for smd. You could be correct but I don't think an inductor would be in a metal muff. Def smart to check before pulling parts.

Yes, if you wanted to you could solder in a 4001 to the pads but it would look pretty redneck.

[PhiloB]

I do love in Memphis;)

[Govmnt_Lacky]

Yes, if you wanted to you could solder in a 4001 to the pads but it would look pretty redneck.

Only to Superman..... who could see through the aluminum enclosure