<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Oops I haven’t been copying emails to the list when answering people.<br class=""><div><br class=""><blockquote type="cite" class=""><div class="">Begin forwarded message:</div><br class="Apple-interchange-newline"><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;" class=""><span style="font-family: -webkit-system-font, Helvetica Neue, Helvetica, sans-serif; color:rgba(0, 0, 0, 1.0);" class=""><b class="">From: </b></span><span style="font-family: -webkit-system-font, Helvetica Neue, Helvetica, sans-serif;" class="">Michael Kelly <<a href="mailto:mike@downlode.uk.net" class="">mike@downlode.uk.net</a>><br class=""></span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;" class=""><span style="font-family: -webkit-system-font, Helvetica Neue, Helvetica, sans-serif; color:rgba(0, 0, 0, 1.0);" class=""><b class="">Subject: </b></span><span style="font-family: -webkit-system-font, Helvetica Neue, Helvetica, sans-serif;" class=""><b class="">Re: [sdiy] SL880 Pro problems</b><br class=""></span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;" class=""><span style="font-family: -webkit-system-font, Helvetica Neue, Helvetica, sans-serif; color:rgba(0, 0, 0, 1.0);" class=""><b class="">Date: </b></span><span style="font-family: -webkit-system-font, Helvetica Neue, Helvetica, sans-serif;" class="">7 November 2021 at 17:19:34 GMT<br class=""></span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;" class=""><span style="font-family: -webkit-system-font, Helvetica Neue, Helvetica, sans-serif; color:rgba(0, 0, 0, 1.0);" class=""><b class="">To: </b></span><span style="font-family: -webkit-system-font, Helvetica Neue, Helvetica, sans-serif;" class="">Mike Bryant <<a href="mailto:mbryant@futurehorizons.com" class="">mbryant@futurehorizons.com</a>><br class=""></span></div><br class=""><div class=""><div class="">Yes, almost exactly the same. A couple of the polarised caps are different, they look like tantalum ones where I have aluminium barrel types, as in the images in your other post.<br class="">I will try cleaning up the IC. I’ve been reflowing some cold looking connections, but it doesn’t seem to have done anything.<br class=""><br class="">Looking at the midi log, what’s happening is a strange sort of buffering - if I press key A2 multiple times, then G2 multiple times, A2 will continue to be sent for say 30 note events while I am hitting the G2 key before eventually G2 is sent. So output is not random but backed up.<br class=""><br class=""><br class=""><br class=""><blockquote type="cite" class="">On 7 Nov 2021, at 16:23, Mike Bryant <<a href="mailto:mbryant@futurehorizons.com" class="">mbryant@futurehorizons.com</a>> wrote:<br class=""><br class="">Does the PCB look something like this<br class=""><a href="https://www.fullcompass.com/prod/276916-studiologic-41911550-main-pcb-assembly-for-sl-880" class="">https://www.fullcompass.com/prod/276916-studiologic-41911550-main-pcb-assembly-for-sl-880</a><br class=""><br class="">If so try unseating the main IC, cleaning all its contacts and those of the socket, then reseating it.<br class=""><br class="">-----Original Message-----<br class="">From: Michael Kelly [mailto:mike@downlode.uk.net] <br class="">Sent: 07 November 2021 11:19<br class="">To: Mike Bryant<br class="">Subject: Re: [sdiy] SL880 Pro problems<br class=""><br class="">Hi Mike,<br class=""><br class="">I tried another PSU with the same results. I put a scope on the voltage regulator and it is outputting a steady 5V.<br class=""><br class="">There’s definitely an issue with the volume pedal input but putting a jack in the socket stops those Volume MIDI messages, so there is some new problem which has developed here…<br class=""><br class="">I’m London based so perhaps there is someone nearby who knows these units. As I bought it for £60 I can’t complain about the service its given me!<br class=""><br class="">Bw,<br class="">M<br class=""><br class=""><blockquote type="cite" class="">On 7 Nov 2021, at 00:00, Mike Bryant <mbryant@futurehorizons.com> wrote:<br class=""><br class="">Have you tried another external 9V PSU ?<br class=""><br class="">If that fails, put a multimeter on the power supply regulator inside and see if it outputs a sensible value (5V).<br class=""><br class="">After that my guess is the MIDI circuit has been honking all these years and somehow the volume pedal has been calming things down. You'll need a scope to check that.<br class=""><br class="">Great keyboard - one of the best - so definitely worth repairing. Where are you (roughly) ?<br class=""><br class=""><br class="">-----Original Message-----<br class="">From: Synth-diy [mailto:synth-diy-bounces@synth-diy.org] On Behalf Of Mike Kelly<br class="">Sent: 06 November 2021 21:04<br class="">To: synth-diy<br class="">Subject: [sdiy] SL880 Pro problems<br class=""><br class="">Hi, I wondered if anyone has experience in troubleshooting Studiologic SL880 midi keyboards. I picked up this one second hand and really like the weighted action.<br class="">Since the off there has been a problem with some rogue midi output signals. Plugging a volume pedal into the volume socket seemed to solve it. Now however after a couple of years of use I am getting random and unstable outputs and it’s unusable. I tried changing a couple of the electrolytic caps as I had spares. The board generally looks OK and the settings functionality and the LEDs all seem to be working fine, so I think there’s not much wrong with it. If anyone knows a likely point of failure on these boards please give me a shout. <br class=""><br class="">I thought about replacing the crystal as it looks a bit aged. Marking is 24.0MHz, HCJ-30 02-02-57. Would any 24MHz crystal do? Or am I on the wrong track.<br class=""><br class="">Alternatively if there’s a way to put a whole new DIY circuit in there I could go that route. They’re Fatar keys I believe, with aftertouch.<br class=""><br class="">Thanks.<br class="">M<br class="">_______________________________________________<br class="">Synth-diy mailing list<br class="">Synth-diy@synth-diy.org<br class="">http://synth-diy.org/mailman/listinfo/synth-diy<br class="">Selling or trading? Use marketplace@synth-diy.org<br class=""></blockquote><br class=""><br class=""></blockquote><br class=""></div></div></blockquote></div><br class=""></body></html>