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Subject: Re: [chromapolaris] Polaris broken.... help!

From: Gregory Cox <adhmzaiusz@...>
Date: 2018-06-06

By the way Bob, Lou’s the guy with the problem, not I  ;)   Anyway Lou, before you set off on a complicated journey, I would honestly re-examine the DC OK threshold in detail.  My main argument of why-- sometimes the power supply DC OK LED comes on when adjusted but may still need a little more juice in some situations to work correctly.  Without the correct DC OK setting none of the digital side will work and the polaris will be unresponsive with LEDs lit just as you originally described.  After making a small incremental adjustment reset the power and see if it helped, then repeat again to see if any higher adjustment works.

A while ago my polaris appeared to be screwed and unresponsive but it was a finicky trimmer on the power supply.  Make sure it’s sprayed with a contact cleaner or something and readjust as described in the service manual.

Greg





On Jun 5, 2018, at 8:13 PM, 'Lou Champagne' lou@... [chromapolaris] <chromapolaris@yahoogroups.com> wrote:


I’m down to two 6264 now with nothing to report after having swapped them around a bit to make sure.

 

Lou

>>

Are the installed RAMs 6264 types? If so, just two of them installed is a valid configuration,
so you could remove all but two and swap those out to see if you have a bad RAM chip. You can see the 
valid configurations and jumper setting in the service manual.

The service manual mentions that U84 and some other gates are not used in the Polaris, and this circuitry
was for something that Fender was developing. I think this is the circuit that was driving PREQ, so 
probably it's OK to be sitting high.

Bob