1N4001 is fine for D2. 1N4148 is NOT the same thing at all for D1. Did you
check to see if the solder pads are there between IC 18 and IC19, where a CR2032
could be installed? My preference would be to just add a battery there and
remove D1 and R1 from the board. If you want to just leave it original and
reinstall patches every time you turn it on, D1 would have to be a zener diode
like the 1N5231C, 1N4733 or BZX55C5V1.
According to some old notes I have on my Poly 800 repairs, I once used a
2SB1314 to replace a 2SB731. I’ve replaced 2SB744 and 2SD794 on a Polysix and
managed to find the right parts on eBay. I haven’t noticed any parts changing
specs on different versions of the Poly-800 boards.
Don Backshall
Sent: Thursday, January 31, 2019 9:53 PM
Subject: [korgpolyex] Re: Korg poly-800 diode info
Hi, you're correct about 596-8 only D2 is on the board w/2032 batt like you
mentioned. But 596-4 does have both D1 & D2 thats why I was asking as the
legs are gone on both components, so would 1n4001 for D2 and 1n4148 for D1 be
ok?.
This 596-4 board is in really bad shape. Some transistors are not original
either and I don't know if they are compatible namely Q1(2sb731), Q3(2sb744) and
Q18(2sd794). I'm not sure that I could find those but would any readily
available equivalent of those be suitable? Btw, would these parts be the same on
other revisions as well? If you could let me know, thank you
again