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Hi,

I recently bought a Korg SP250 on Ebay sold as parts only. The vendor said it simply didn't power up one day. When it arrived it looked like new, great condition but sure enough it did not power up. I opened it up and was surprised to find the power pcb was all split and components were hanging off the board. Looks to me like someone yanked the keyboard up or down while the audio cables were still plugged in. The damage has been caused all around the jack plug sockets. I thought about trying to repair but I'm pretty sure its a right off.

I've had a look for a replacement on line but so far no joy. Can anyone recommend a supplier or is anyone breaking a Korg SP250? It's the SP250 Amp Board.

Many thanks Alan

This one?

https://syntaur.com/Items.php?Item=5647



Out of stock right now. 😐

Yes that the one. My one has a crack that runs in an arc around the two black Jack sockets.

I'm not sure how to add a photo?

Alan

Hi Alan3666,

As you're UK based try Nigel at W D Greenhill & Co (https://www.wdgreenhill.co.uk) if Korg themselves are unable to help.

Good luck,

Tog

Cheers Tog! I'll try them..

I did get a response from Korg but it was just to say the part was obsolete.

Alan

I sent an email to WDGreenhill asking about the part.

I said I would take a faulty unit if they had one. I'm pretty sure the components on my damaged unit should be good to go.

I'd just need to brush up on my soldering skills.

sAlan

Hello,

@Alan3666, Looking closely at @clothearednincompo's photo, together with your indication of where the crack is, I reckon this board is repairable if you can't find a replacement. Don't give up too early (which I get you aren't)!

Cheers and happy piano rescuing,

HZ

Hello HZ,

thanks for the encouragement. If I knew how to post a picture I think you'd probably agree it is beyond repair. I thought about tracing etches and running wires but I'll park that idea for a bit. I removed one of the audio sockets and a big chunk of the pcb then fell off. It wouldn't be impossible to fit it all together like a jigsaw puzzle and then run wires to solder points but it would be a pain.


Not giving up!

Wish I still had my old oscilloscope

Maybe ask Korg support if they could share service manual (not user manual, but the thing they share with their repair services) or this amp board specification: I believe it can be exchanged for something else.

OT: Time flies so fast, I remember my excitement when my parents bought me Korg SP-250 (my first proper digital piano!) as a reward for good grades after first year of high school. It was 15 years ago.

Thanks ABC,

I have the service manual. There's nothing to lose in trying to piece it all together but we're talking about a lot of patching/soldering. I cant believe how much damage has been done. If only those jack sockets had been secured by nuts. there are threads for nuts after all.

Oh joy!

Hello,

@Alan3666, Imagine the sense of pride and accomplishment when you succeed... 😋.

At the moment I'm also restoring some 'old' but lovely equipment and the process can at times be a pain indeed. Not to mention the scare it presents to the insecure persona within ourselves. But when the last screw goes back in, lights come on, and everything functions once again for hopefully years of good enjoyable use to come, that feels sooo good.

Cheers and happy restoring,

HZ

@Alan-with-three-sixes, great you got the service manual! If that was the damage board in #Post3139885 image, it would be fairly easy to trace since it has discrete components surrounding the jacks instead of ICs. Probably, it would be nice to start with the dc jack, labelled OJ1... if only the cracks where only nearby the jacks...
Hoping to join that adventure!

Hello,

@Alan3666, Wow. Someone must have been really violent and/or angry at some point to create such a damage.

Still, a restoration doesn't seem undoable to me. Tool-wise, there's a start, 😀, I'm using that one a lot myself these days/weeks in restoring my three nice decades-old Onkyo amps (to be used in my piano setup and regular HiFi/TV use).

Cheers and happy reclaiming,

HZ

Oh man! That is some wreck! I believe you can restore the board traces. Was their any jacks on the broken off piece?
Cause if there is, it won't be strong enough unless you pour some clear epoxy on the non-contact side to keep the board from cracking again since the jacks doesn't appear to be screwed on the back panel.

Ok so here is where I am. I don’t think the old Amp Board will be an easy fix. All the components are there but the cracks on the pcb run everywhere. I found a guy on eBay who was selling SP250 parts. He had a few listed but no Amp Board. So I contacted him and asked if he had even a faulty one. It arrived this morning and I fitted it this afternoon. Everything powered up fine. I had sound on both audio ports, both left and right headphone but only sound on right speaker. The guy said he had put it in for repair and the shop replaced a couple of parts but it came back with still only one working speaker. I’m pretty pleased with this progress but I’d like to get that left speaker working. From the disturbed solder it looks like they replaced IC2. I bought an old oscilloscope which should arrive in the next couple of days. Wish me luck. I started out working as a repair tech for digital equipment corp, so I know how to work the scope, but that was over forty years ago.

Might have to read the manual

http://forum.pianoworld.com/ubbthreads.php/galleries/3141224/sp250.html

Here is the schematic if anyone is interested.

The Audio left and right is shown top left, the head phones left and right is bottom right and the speaker outs are top right.

It looks like the power amp IC2 has been replaced. When the scope arrives I'll check on pin 7 for a signal. If there's nothing there I'll start working back. It might be a fault in the EQ, IC1.I hope not.

Anybody got any suggestions?

Alan