Mains TX outputs for Line 6 Spider 4 anyone?

[allante666]

Hi Enzo. yes I have two drawings an dthat one does show U14 which is correct but the similarity ends there, mine is still very different. Im not even sure mine has the guitar sense circuit at all. That IC does have power to pins 8 and 4 as it should do. If I inject a signal directly at either pin 7 or 1 (outputs) I get nothing. (at either end of the connector cable). That AK4552 isnt on the main board (U2 is a regulator). It might be on the front panel board Im just going to strip it and have a look. (the user interface board. I wrongly called the main board that earlier). There are no test points marked on the board at all save for a few A_gnd ones which im taking to be audio grounds.

[allante666]

nope, no AK4552 anywhere.

[allante666]

ok so what i did find is a CS4727 which Im guessing is what they have replaced that AK4552 with. Its the codec chip. If I inject signal into it I get nothing out. If I inject into the output pins I get a signal out as normal. It has all its correct supplies so Im guessing this might be an issue with the DSP not sending th e processed signal back?

[Jazz P Bass]

I have had to replace that CS4727 in the past.

If you have signal In & no signal Out and all of the other pins have their proper voltages, then it's time to try a new ic.

[Enzo]

I was going by the schematic, if they used some similar chip in your unit, the procedure remains the same. As Jazz pointed out, if you have input to the IC and no output, yet signal injected at that output continues out the speaker, then the problem is in the digital section. That IC interfaces with the analog world, but there is also all the DSP stuff. Make sure the logic voltages are present, the 3.3v, and maybe 5v.

[allante666]

Yeah I think in the interests of my eyesight Ill replace the codec chip and see what happens. I dont mind doing surface mount stuff but that DSP chip has like 3 million pins, or thereabouts... Ill get one ordered and report back on this thread, Ive seen line 6 amps with no audio reported before and gone unsolved so if it works ill let you know. Thanks.

Incidentally, anyone know of a source?

[Jazz P Bass]

My notes indicate that ic is a Cirrus Logic CS4270.

CS4270-CZZ-Cirrus-Logic-datasheet-38890.pdf

Digikey has them.
CS4270-CZZ Cirrus Logic Inc. | Integrated Circuits (ICs) | DigiKey

[allante666]

Yes its a CS4272-CZZ which they do have but I'm in the UK. I've found a supplier I'm just waiting to hear back from another one with a price.

[allante666]

UPDATE! As promised, the results are in..

I changed this 4272 IC and Lo and behold! we have audio restored!
Many thanks to all who commented.

To save anyne going through the thread, the symptoms were everythign lights up and operates as normal, including the MP3 input socket. No audio from speaker or headphones.

[Jazz P Bass]

The last time I got one of those IC's, it came in it's own box, wrapped in sealed anti static and there was a humidity indicator tag on the box.

Touchy, touchy.

[allante666]

It wasnt quite that bad it just came in antistatic foam but I still took precautions. Im just glad it turned out to be this one and not the million legged DSP chip. I think that would have condemned it to the scrap heap!