Replacing a fried SMT transistor without having schematics

[sandord]

Hi,

I'm trying to fix my mum's Logitech UE Smart Radio (which is a rebranded Squeezebox Radio). It suddenly stopped working and after opening it up, I quickly spotted this resistor Q3 which has obviously gone to heaven:

sr.jpg

The thing is that I can't seem to find any schematics for this device. Besides, the resistor spec can't be read from the now fried package.

Is there perhaps any way of making an educated guess or somehow determining a safe replacement part?

[exxos]

Hard to tell what's going on.. Might be voltage regulator :shrug:

[Icky]

Hard to tell what's going on.. Might be voltage regulator :shrug:

Am thinking the same based on the track thickness etc. Looks like a voltage regulator. Could it be similar to Q5 above.

EDIT: if it is similar to Q5 above that has a Z4 marking which is either a zener diode or transistor - http://www.s-manuals.com/smd/z4

[xyzzy76]

Looks like a common fault.

https://forums.slimdevices.com/showthre ... post918596
https://forums.slimdevices.com/showthre ... post862112

[sandord]

Looks like a common fault.

https://forums.slimdevices.com/showthre ... post918596
https://forums.slimdevices.com/showthre ... post862112

Ah, that's quite right. So much for my Google skills :roll:

I'm thinking of removing the amp chip (+connect S&D at Q3) and see if it powers up again.

[sandord]

I'm thinking of removing the amp chip (+connect S&D at Q3) and see if it powers up again.

I mean, I could always run the headphone output through a cheap digital amp circuit and connect it to the speakers. Though I'd have to make sure it can drive a woofer and a tweeter separately.