OP-1 Connector Board Mic Troubles

Hey folks!

I picked up a used “mint condition” OP-1 on eBay about a month ago and I’ve unluckily just discovered that the connector board / mic. input is totally hosed.

The internal mic. worked fine so I assumed the rest was good. However, upon plugging something into the mic. jack for some sampling funtimes, I discovered that: a) input no work! and b) now it wouldn’t go back to the internal mic. (always thought something was connected).

To make a long story short here’s what I discovered: whoever had this unit before me decided to replace the jack themselves and lifted almost all of the pads! No wonder it doesn’t work. Here’s how it looks with the “fixed” mic. jack removed and cleaned up:

I got a replacement mic. jack but where I’m stuck at is figuring out where these pads need to go. There’s some vias in and about them so it’s difficult to trace, so I’m asking — is there anyone in the know that has a schematic for this board? Maybe someone who can probe their own board and tell me where I can bodge wires on?

If anyone has a connector board to sell to me in the UK, that’d also be a big help! I can’t find them in stock anywhere. I’d much rather repair it though since it’s such a stupid problem.

PS: If anyone is else is looking for it the closest microphone jack part number is SJ1-3515-SMT-TR-PI. Digikey has stock. I think TE must have got these custom-made in their colours, but they’re the same essentially.

Sorry for the multi-post but I can only post so many images as a new user. :slight_smile:

I did discover that if I short the two exposed pads, it swaps back to internal mic. fully. When I plugged in my jack initially, it must have broke an existing short, or something? No idea.

A friend did manage to probe out his somewhat partially if it’s useful to anyone:

Bodging these connections back together DID bring back external mic. input but still no swap-back-to-internal-mic. so we’re definitely still missing something.

Here’s my bodge — definitely need some thinner wires but all the connections probe correctly with no shorts:

As mentioned, this did bring back external mic. input but didn’t bring back the internal mic. when you unplug.

The jack has switches on the mid-left and mid-right pins that are normally-closed. When you plug in a mic., it opens these switches so I imagine there’s something not quite wired up right with my bodge here that would bring back the internal mic.

the jack uses a very common switching mechanism.
this is what the OP1 uses to tell if something is plugged in and if nothing is.

so like when the jack has nothing plugged in, one of the lugs is connected to the tip connection
and another lug is connected to the ring connection.
when u insert a plug into the jack, these connections break.

so u dont’ wanna bridge those connecitons yourself u want hte jack itself to do that for u.

edit: ah i see u sorted that out


Hello! Yeah, I figured out that they have switches in the jack eventually. :smile:

But since the pads are lifted, whatever would normally help make the detection circuit work is missing I guess even with my bodge wires.

there maybe multiple traces // connections coming off one or some of those pads?
i dunno sorry i am not more help atm
shame whoever tried to replace it initially did such a shit job.

edit: can’t u flip the board over and follow those vias?

I’m gonna have a good go at it again in the next day or so again and see if I can draw out my own schematic, for sure. There’s a bunch of vias around there, including on the lifted pads itself. I’m decent enough at soldering, etc. but not reverse-engineering, haha! Especially on a mutli-layer board with this lovely black solder mask that makes everything impossible to see. :smile:

I’ve emailed TE already too asking for a schematic (and general guidance) but I don’t have much hope for that end of things.

For sure as well. I’m gutted because I already got a partial refund from the seller on eBay for a overly sensitive key (not note keys, thankfully) but eBay have already said they won’t help me with a second refund.

get that multimeter out!

if u can’t suss it out, the good news is
the connector board is prolly the most popular // common replacement part
so ifixit will most likely get htem back in stock at some point.
maybe sign up for that notification email?

TE got in touch with me in the end and very kindly provided me with a purchase link to a new board! Big props to them — was expecting I’d have to wait for a good while.

how much was the new board? the old one looks so crusty! I wonder what happened to it

It was a little over 60 GBP delivered — just waiting on it arriving now!

I know right, as well? Repair gone wrong, is all I can assume — didn’t realise missing pads were a problem?

yeah, the worse is the “mint condition” bullshit…