Transistor for Epson 1650 Photo Scanner?

[Jesse Hong]

Hello,

I'm trying to fix an Epson 1650 Photo scanner for a friend.
It was dropped and the USB connector was yanked out of the
PCB and appears to have sheared off a transistor right behind
it. I have replaced the USB connector, but the transistor
is no where to be found.

Anyone happen to know what the "QF1" component on the PCB
directly behind the USB connector should be? It looks to
be wired through a resistor to the +5V pin of the USB on
one lead, ground on another, and to a capacitor and more
stuff on the third.

I've done some searching, but haven't found anything, not
quite ready yet to get a service manual just for this one
piece of information which may not end up fixing it.

Thanks!

 

[BFriedl]

just thorowing my $.02 in, seems to be a voltage regulator for the
scanner. Perhaps VCC is 3.3vdc, and not 5v in this case? IS the unit USB
powered or does it have an external supply?

Hello,

I'm trying to fix an Epson 1650 Photo scanner for a friend.
It was dropped and the USB connector was yanked out of the
PCB and appears to have sheared off a transistor right behind
it. I have replaced the USB connector, but the transistor
is no where to be found.

Anyone happen to know what the "QF1" component on the PCB
directly behind the USB connector should be? It looks to
be wired through a resistor to the +5V pin of the USB on
one lead, ground on another, and to a capacitor and more
stuff on the third.

I've done some searching, but haven't found anything, not
quite ready yet to get a service manual just for this one
piece of information which may not end up fixing it.

Thanks!

--
BFriedl
A+ Certified Technician
AIM: UACybercat
** Bear Down Arizona! **
******* Go Cats! *******

 

[Jesse Hong]

It is externally powered. I'm not that knowledgeable on
circuits, but yeah, I also think it is probably part of a
circuit to regulate current/voltage off the USB line...

I'd like to try to get the exact part if I could, but
if I had to experiment, I could just try getting any npn
surface mount transistor and see if it works... and in
that case, any educated guess might help.