Good morning guys and thank you both.
Attached 2 more pictures of the front and back of the pre-amp board. I
These are 2 that I took prior to dismantling, and as said, the board is not being tested out at a pcb manufacturing firm so I cant get more at the moment
The problem started about a month ago. This is an Orla GT8000 organ. It is a true organ and NOT the Orla 8000 Sport, which has a single keyboard.
I started to get a lot of crackling through my headphones whilst playing. I examined the headphone sockets (2) and found them to be fine. Also tried 2 other sets of headphones that I know to be good. Removed the headphones altogether, and played through the main speakers. This worked fine, and I was able to play again with no issues. But soon I had the same issue with the sound coming and going and not responding to either the main volume switch on the organ, OR to the swell (volume) pedal on the lower section. The swell pedal socket has a switch, so that when removed, all volume is then switched to the main amp.
Then, inevitably, turned on 10 days ago, and zero sound. All the lights are on, and pressing the master panel buttons does everything it should...rhythm lcds are moving etc. But no sound
Spoke to a guy who did some work for Orla. I have replaced, on his advice, the 2 swell pedal pcb's, ribbon cable that connects them, and both leads and plugs to the preamp board with new parts. Also replaced the main volume switch and the stereo jack socket on the preamp board, but without success. It's definitely a sound issue.
What SHOULD happen, is that the organ can be played either on headphones or by operating a switch on the rear of the instrumenf, I can switch to main amp which lets it be played at full volume. I very rarely use it without headphones, as the speakers are extremely powerful. What IS happening is that NO sound is being produced at all.
On the preamp board. Power comes into the socket from the toroidal transformer via a 5 pin plug. It then should transfer to the organ but is not doing so. The fuses have been replaced with new ones. There are 2x500Ma fuses, and 1x3amp. There are 3 banks of sockets. 4 are midi connectors which I don't use. 4 are in and output sockets for extra external feeds which again I don't use. The two on the end are Pedal Sustain which is the outer one (unused) and the inner one is the Swell pedal volume socket, which has been replaced with a brand new one as we thought this was the issue.
The main amp has been tested by running a direct connection via a cable through the input sockets from a radio, and there are certainly no sounds issues there..... It is VERY loud.
That's all I can advise. I am desperate to find the reason for the complete lack of volume. Unfortunately the complete preamp PCB boards are no longer available so I can't just swap it out.
Help!! Really stuffed. Thank you.