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=167391In 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.
> >
> >
>