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Re: stange jp-8000 start up behaviour
Posted: Wed Jun 23, 2010 10:26 pm
by garranimal
I know it sounds really simple but my last JP-8000 had audio crackling issues due to the big ground plane wire coming loose.
Re: stange jp-8000 start up behaviour
Posted: Sun Jun 27, 2010 5:08 pm
by x11o8
Ok here's what I have done so far. I reseated the ribbons cleaned and them with deoxit. checked all the ground connections, deoxited the pots and jacks.
nothing changed so I recapped the jack board. It still has the same problem.
the two dip chips were not opamps they were a hex inverter and optocoupler
the opamps are both sips they are:
M5218AL
UPC4570HA
Should I try and replace these? Do opamps go bad like this, I have never seen it, usually they either work or they don't right?
thanks
Re: stange jp-8000 start up behaviour
Posted: Sun Jun 27, 2010 6:15 pm
by gearfixer
You did check the solder connections of the output jacks?
Re: stange jp-8000 start up behaviour
Posted: Sun Jun 27, 2010 6:54 pm
by x11o8
I looked over all the solder connections on the whole jack board with a magnifier just to be sure.
Re: stange jp-8000 start up behaviour
Posted: Thu Jul 15, 2010 1:03 am
by x11o8
I got the two chips (M5218AL,UPC4570HA) from mcm and replaced them, there was no change. its starting to look like its not a problem on the jack board. That leaves the cpu board, and that is all surface mount, and 4 of the chips are proprietary also, the converter isn't but nobody has any for sale.