I powered up the 800 and looked at that those diodes, the first row of diodes actually lit up, the diode that was attached by a former owner did not, at closer inspection one of the leads was broken off, I moved the broken lead back on and it still didn't light up. Looking at the parts list it looks like these are 1s-2473 t-77. Can I swap this with a 1N4148? http://www.audiokarma.org/forums/showthread.php?t=167391 In this application these people said it was okay. 2473=35v 100ma 4148=100v 450ma ( I haven't double checked this) and then this: http://search.retrosynth.com/synth-diy/search/lookit.cgi?-v0106.202 --- In korgpolyex@yahoogroups.com, Michael Hawkins <korgpolyex800@...> wrote: > > Actually, the early Poly's had LED's in those steering diodes. So the LED is not entirely out of place. It's certainly not the first place to start looking, that's for sure. > > > > ________________________________ > From: bimmerfan222 <bperkins211@...> > To: korgpolyex@yahoogroups.com > Sent: Tuesday, September 18, 2012 1:14 PM > Subject: [korgpolyex] Re: Just made a trade for a broken poly 800! Problems at first glance! > > > Â > > > Hard to tell from the pics, but I wonder if the prev. owner/butcher managed to somehow re-route the external power connection direct to the battery terminals and that's why it powers up when you plug a wallwart into the 9v DC input jack. > > I think the LED they put in it was perhaps either an activity indicator or they simply didnt have a standard diode to put in.. so they used a LED instead (not a good idea since it gobbles up current). > > Since it does power up and you have LED display activity, it sure sounds like it's not dead yet and perhaps recoverable.. just going to take time/patience to go thru it and restore it to OEM specs. > > -Blaine > > --- In korgpolyex@yahoogroups.com, Tavish McDonald <tavishmcronald@> wrote: > > > > Yeah this thing is definitely going to need some work, I thought getting it > > cleaned up would be a good place to start while I find parts. I have > > powered it on with an adapter without Q1 somehow, I wonder if the > > nonfunctional headphone jack has anything to do with this transistor. I > > have the service manual. > > > > Yes the compartment shows signs of battery leakage. > > > > http://www.sdelectronic.rs/php/elm.php?prm=TR2SB > > based on this it looks like TR2SB764 is 60v 1a 10w. Is that what I need to > > know to find a replacement or is there more to it than that? Obviously I > > don't know much about electronics/transistors. > > > > >
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Re: Just made a trade for a broken poly 800! Problems at first glance!
2012-09-18 by mcdonaldtavish
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