I'm pulling my GS forum post here as the questions are better suited for the EE community.
I have a Focusrite 2i4 usb audio interface. The Focusrite Scarlett line shares these components I have listed in most of the models they offer.
Background Information/Issues/Symptoms:The pad and phantom buttons (internal led) DO light up if I push them and the device is plugged into usb port.
The 1-2 input gain knob "halo/ring" shows no lights (should light up when input is detected from mic/instrument pluged in). And midi/usb activity light are very very faint, not bright/fully green/active (should be an obvious bright green)
The device is NEVER seen by windows (or mac) in the DevMan.
TL;DR:So I suspected it had to be some type of USB controller/board issue.
I found some tear downs of these Scarlett's and found the internal components used.
Quote:
Chips:
XMOS XS1-L01A-TQ128- (GT1244L1 C5 PKH293.09) - Microcontroller (500MIPS, 32BIT, 64KB SRAM).
Cirrus Logic CS4272-CZZ YFAABXNJ1238 - 114 dB, 24-Bit, 192 kHz Stereo Codec.
AKM 4384ET 6R230 - 106dB 192kHz 24-Bit 2ch DAC.
JRC 4565 C096F - DUAL OPERATIONAL AMPLIFIER.
JRC 2122 C109H - ULTRA LOW NOISE DUAL OPERATIONAL AMPLIFIER.
ATMEL AT25DF041A ATMEL1113 - Serial interface flash memory device.
Texas Instruments TI HC4066 2BAQDCK G4 - Quadruple Bilateral Analog Switches.
SMSC USB3343 1511900 - Hi-Speed USB 2.0 Family Featuring RapidCharge.
CN PC900V - Photocoupler.
7519A G2KSZ
C1L95 Y72
After a lot of digging, I found 1 person who attempted to repair their interface.
This person replaced 3 chips. (The xmos controller chip, atmel serial interface flash chip, and the USB3343 transceiver chip.
They claim after replacing these chips....they have their Focusrite device functioning again!!
Now......I don't even have the proper equipment for this repair (bare bones experience).
I don't even have a DMM, I have an old analog multimeter.
So, I'm thinking if I can find a electronics repair shop and order the chips, I may can salvage mines.
Update:
I had found one more person (so now total of only 2 people have attempted this repair¿), But they only replaced the USB3343 chip, which makes sense, since this is the usb interface and is what interacts with the computer.
I do not know how to test the IC's as to know if I need all 3 chips, or just the 1. And from reading, I cant really test them with MM, I can just find a short maybe??
Here are pictures of the interface board and IC's in question:
http://img.photobucket.com/albums/v2...209_200201.jpghttp://img.photobucket.com/albums/v2...209_200211.jpgUpdate 2:
Wanna-Be Soon-To-Completely-Fry-Anything-That's-Still-Good Amateur Electrician checking in...
Ok, as I said I don't have a DMM.
So I used my analog MM and set it to ohm mode. I grounded my ground lead to the rca jacks and started touching some of the IC chip legs.
So on the pretty much all the legs of the atmel chip, my meter I think is what you call..open-looping (like when you are touching the - and + leads together)
On the USB3343 chip same thing
Now, on the xmos microcontroller, when I run my + lead across the bottom legs,
on 1 leg I can get the midi LED to come on solid green and another leg close by it, if I touch it, I can get the USB light to shine.So I have to extrapolate for now that the xmos chip is at least good/working?
And I don't understand fully yet what the serial interface flash memory chip does, so I can't rule it out.
The USB3343 transceiver chip would be the only for sure suspect, but I would hate to find out it IS working and something else down in the chain is causing the issue instead.
So basically........what things can I do myself at this point?