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looking to get a sencore cr7000 repair

XeD

XeD

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I have a CR7000 that does not fully work. Power on ok and show signs of life. Once it get to the Cut off setting and beyond it does not work. I can not dial it in.
 
really? From everything I read people say they stop servicing these years ago. I guess I'll give them a call on Monday.
 
Let me know. When I checked a few years ago they still did. I still use the sencore-e site to set my unit up for repairs.
 
"I am sorry to say that Sencore no longer offers service support for the CR7000 at our Sioux Falls facility.

I can offer service support in the form of schematics, manuals, field test documents, and some parts.
Sencore does not authorize or endorse any third party companies to perform repair of our equipment."
 
Ask them for all of that. Especially the documentation and schematics. And ask what spare parts they can offer please.
 
I have all the docs. Will post a Dropbox link when I get a chance. Parts are on a request bases as he need to know part #
 
Thanks for sharing these, man!

As there are parts which are custom, like coils, programmed µC etc, you might want to order a few for the future ...should you decide to reverse-engineer/clone the thing.
 
Well I have narrow the problem down to the top board. Can anyone with more electronic experience help me pinpoint the problem? The unit work for the most part. Fil voltage 0-4 and 4-8 Does not display, it measure correctly with dmm. 8-16 work. Cut on all 3 guns does not dail in.
 
Sure thing, XeD.
From the very little details you have stated so far I can only guesstimate however. And my opinion can only be based on my understanding of what you write. A more detailed description of what you exactly see, what measurements you have done and how you ruled out the other boards would be very helpful.
Apart from the obvious voltage measurements, Y1 and C52, which you probably already verified, I can suggest checking U2, U3, U4, U6, U10, U12, U23 and U26. Do you have an oscilloscope or just a DMM?

EDIT: I forgot to mention that U26 would be my suspect #1 as it is common to both defects you mentioned.
 
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Thanks Asayuki,

I came to the conclusion about the top board from the following:
- All setting read inspec using a dmm. Fil voltage, bias voltage, cut off, and all the rejuv functions. So main board work.
- using an logic prob as my poor man oscope I can hear an audio difference from the fil adjust on 8-16. 0-4 is the same sound. 4-8 has 2 tone when it jump from no led to all led at around the 6.5. To me that would mean top board

I do not have an oscilloscope. I have swap out the u26, u12, and u10. I guess I have to order the other chips to test.
 
Your measurement on FIL_ADJUST leaves me a bit puzzled. As far as I understand from sheet 3 of the top board where the filament adjust pot R17 is located, the entire area is entirely analog and shoudln't produce any sound except from S2 pins 1, 2 and 14. Not that this is so important, but just to be sure I am correctly following what you did.
Anyway, I still think it's a problem related to the MCU not being able to read data from the outside and expecially from the ADC (which as you have guessed is the chain of components I already pointed out).
I would check that U26 pin 1 and 19 are being driven (from U27 and U28). Also it's a good info to know if ADC_DAT (U26, pin 17) as well as the other inputs of U26 are doing stuff.
As far as I get from the datasheet, the 80C32 (U17) is romless, which means the 27C010 EPROM U1 contains the MCU's code. Aside from the repair effort, I would suggest to dump it and keep it aside for the future or for other Sencore users who might need it.
 
I will look into that when i get some free time. I will also dump the rom and put it in the dropbox
 
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