EAD DSP 7000 mkII not locking

I have bought this dac from an German fellow who told me the dac was perfect. But sadly it's not. He does not answer anymore messages so i am now stuck with a nice defective DAC. Thanks for that!

The unit does not lock on any input, so no sound on both outputs. I have tested multiple sources and cables. Also i replaced the CS8412 but that did not helped. The regs and PSU are al oke. There are no scematics online and i have no scope. What will be the next "usual suspect"; the DF1700?

I don't have any at hand for testing unfortunately. If somebody have any other sugestions, i would be greatful.
 

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Without a schematic, the usual approach would be to get data sheets for the ICs and then start checking voltages and scope signals to see if they are what the chip needs and or what the chip should be outputting. Maybe you need to take the unit to a repair shop? Or, maybe its time to invest in a used ebay scope?
 
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I agree with Markw4. About the best you can do at this point is to find the chip(s) data sheets and begin testing power circuits. The EAD stuff sounded incredible, but the caps were a weak link. I owned a DSP -7000 III , DSP 9000- III pro. and T- 7000. Sold the 7000 to buy the 9000. Lost both the 9000 and T-7000 due to leaking caps that destroyed the circuit board substrate. I could, probably, repair them with the skills I have now, but not 15 years ago when they failed.

Good luck! It really is a great D/A converter.

Dan
 
Will do that in the weekend. Maybe post the results here.

Looks like a great converter indeed. Nice project for a recap. I did not wanted the MKIII for the "digital flywheel". If that would go defect it looks hard to repair. No i'm stucked with a defect MKII....
 
Solved!!! I was going to connect the spdif bypass on the CS8412 to to rule out some things. But when i did a continuity test where to connect the wires i noticed that the 10nf on RXP did not had a connection. No matter how i did flow the solder it didn't connect. After looking with a magnifying glass the thrue hole didn't look so fresh. So i made a jumper for now and bingo, signal lock!

Realy a needle in a haystack without a scope. Thank's to the suggestion of rfbrw.
 

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