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BobtheBuilder

Crown CDi 1000 No Power

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I have just received a Crown CDi 1000 from a friend and I'm hoping to get it working for him. He was about to toss it but I said I'll just try, so there nothing to loose.

Symptoms are, no power, nothing not even a light flicker and a burning smell.

What I have done so far is checked the board for and obvious issues (bad cap, leaky cap, burning marks, etc.). All looked well, I then checked for shorts and found Q28 or Q31 to have been shorted, unfortunately I do not remember which one. I replaced both the with HGTG30N60A4D the correct part. I also checked C196 cap for an issues and it tested fine, but I have a few extra 105 Degree 220uf 50v lying around and replaced it anyway.

So with all that done, I plugged the amp in and pushed the power button and... no power, nothing, no lights. But there is no more burning smell, so that's good. 

So my question is, how might I proceed? I'm really not sure where to check.

Any help would be greatly appreciated, and I would be very grateful. I would love to save this awesome amp from the landfill.

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An update from further testing, C63 test shorted using the diode testing function on my DMM. C64 does not test open, I am not sure if it both capacitors are supposed to be that way. I did a test procedure from this post

Remove R375; Scope or check the voltage on the zener, with reference to the bulk return reference (TP21. Note: this is not a chassis ground. BEWARE!)

With the resistor removed, four different signals should show on D8:

0V : the load resistor is open : check above; If resistors and D8 are fine, then you may have an issue with IC16, the Fault circuit or the crowbar circuit;

16V: the load resistors are fine, downstream you may have a shorted bypass cap or modulator is disabled (possible short in amp detected);

2V : if steady, then the kickstart cap (C196) is open (apparently, not this case!);

2V : if charging and discharging : kickstart cap is functionning; check the bypass caps (such as C201, C196, etc);

I have on D8 2V DC not changing at all. I put the negative lead on ground (I hope thats correct).

I also have about 6v AC on c196

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