Please, please, please don't just have a go! Things may work out really expensive for you if you screw it up. I'm a nice guy and I often don't charge for the time that it actually may take to perform a rescue operation.
A few weeks ago, I received a module-board from a Roland JX-10. It had a couple of faults on it which the customer was unable to fix so after a couple of failed DIY repair attempts, he decided to send me... just the board!
I pretty quickly tracked down a duff 82C54P timer IC. I always try to replace ICs in vintage gear with the same devices and on this occasion, I didn't have any of these in stock. That meant I had to wait some time for an order to come in.
It was quite apparent that all of the 4051s had been replaced. 🙁 Note how the turned-pin IC sockets are extended and cover up the PCB component reference. Seriously?!?!?
So knowing that things wouldn't be as simple as changing a duff 82C54P, I proceeded to check connections and discovered three that weren't... connected, I mean.
Incidentally, buzzing out one of these boards requires a lot of time, patience and coffee!
Final testing and at last, everything seems to be working. Of course I'll need to go through a whole bunch of routines to be sure. 🙁
Eighties synthesisers are just beautiful but they're also incredibly complicated and being thirty-something years old, they're also a little fragile. Today there's a wealth of information out there on the www but you still need to know what you're doing. Service notes are often riddled with mistakes for example and following them as if they were written in stone, is a common mistake in itself. So unless you have the right equipment, knowledge and experience, please don't just have a go!