Trouble Shooting Help

[mcb]

Recently the SPDIF in put on my KDAC stopped working.  The sound of silence was not good

As my dac is fitted with one of the Scott Thomson boards, I swapped the input back to the I2S input (and changed the jumper settingsa) and all was well.



After some more exploring, we narrowed the issue down to the DAC and not either the transport nor the cable.

I then took the KDAC to one of the local tech's to have a look.  He has established that it is the board and not the RCA nor connectors to the board, however he was unable to help any further as he has no knowledge of the board.

So can anybody advise where I can get a wiring diagram from, or provide any other pointers on how to identify and resolve the problem

Regards

Murray

[stevenvalve]

Murray I know quite a few techs around who own KDacs, i can put you on to them. There is a chip on the end of your board that handles the SPDIF  information and if damaged will need replacing. That chip is cheap, but it is a pain in the ass delicate job to replacing it, You need an fine fine tipped iron for the job and a good magnifying glass. Let me know if you want the board looked at, and i will give you the info. Paul or Craig can do the job no problem. Murray, i still have a brand new Scott board, all fitted and ready to go. It is a new spare i made for my DAC, i thought i may need it but that seems unlikely after all these years, it is a lot cheaper to fix yours and it is easy to fix. Its most likely the chip is the cause.

[mcb]

Thank you for your reply Steven.

Seems like the best way forward it to try replacing the chip first. 

Do any of the techs you referred to reside in Perth?

Given that my board has a number of outboard caps connected to it, it will be a major exercise to take the board out and send it east. It is well past my ability to remove and resolder all the connections and I would be very reluctant to send the whole dac away.

So unless you know of any techs in Perth who are familiar with the KDac, I will see if the guy I saw can have a go, if I can provide him with details of the chip in question.  He was able to turn the board over without dislodging any of the wires and he has a massive light magnifying light.

If you can point me in the right direction as to either: i) a Perth based tech; ii)  the chip details; iii) who can advise me the chip details, it will be greatly appreciated.

Regards

Murray

[stevenvalve]

Murray a picture tells a thousand words, This is most likely the offending chip, but it could be any number of related stuff, may be bad connection good luck.

[mcb]

Steven,

Thank you for the photo.

Just to clarify, is the chip that you are referring to, the bigger one with the legible numbers (CS8414-CS), or the smaller one above it and to the left.

Thanks

Murray

[stevenvalve]

Yes, the big chip, you can see the tracks running off to the section that has the push on pins to change it to run SPDIF. Did you did connect the ground pin with a jumper as well. Sometimes the solder joints on the chip to board can be the problem. resoldering them sometimes works. This was a common problem with these older boards

[mcb]

Thanks very much for the clarification Steven.

I don't think anything was done with the ground pin.

Hopefully I now have enough info to make some progress.

Regards

Murray

[mcb]

Hopefully this is my last question on this subject, are there any known sources of the CS8414-CS chip in Australia or alternatively, reliable OS suppliers.  I have found some on EBay, but have no idea as to whether they are likely to be genuine.

Murray

[stevenvalve]

Murray, Craig in Queensland will have them, or where to get them, get the number from Mario, But its no certainty that the chip is the problem, just a high probability.

[mcb]

Thanks Steve,

Fully understand that it is no certainty that the chip is the issue, but lets hope that it is.

Murray