Its something more manageable. The power distrubution panel is bad. Thats why your LEDs arent working and you arent getting any power through your analog section.
In the database page, look under the maintenance section, under the part where it talks about the rail caps. Its not a rail cap problem you are having...but under that it talks about loose power supply cables.
I had this problem this week. And still do. My board boots up, loads cards and lights up and everything. But no response with cpu & no audio and no leds. So i opened it up and started playing with cables. I knew it was power related. Something wasn't grounding right on thw dsp or power supply pcb. But none the less, the twisting of the chassis as I picked it up and sat it on its side fixed it momentarily, again, another indicator that it was power related and something loose inside.
So, to make a long story short I swaped out the molex power cables coming off the power supply (grey 4 wire w/white ends) going to the board that sits behind the card cage.
Luckily I have a spare board i could pull parts from so i was able to repair it. Basically, the white power connectors become loose so you have press them back in to make a good connection. But in some cases where its too far gone, you have to replace the green part directly behind the power connector and the power distro board behind the card cage.
Then I took my hand and gave the braincard & distrubution card a tug (thinking it wasnt grounded properly and to "unfreeze" it). When working properly, the brain card will have a green & red light and the dsp card will have a green light. If you see red it stuck somewhere and the board is frozen (lit up like a xmas tree & frozen).
So my suggestion is stand the mixer up on its side. With the bottom removed, and power & data cable connected.
Dont disconnect any cables but rather press down hard to secure a tighter fit or better connection on those power wires I mentioned earlier.
After giving everything a good tug, power down and power back up and see if you get anything. Any signs of like, the faders calibrate, reset, led spike...anything. if you do, then you are on the right track. As the database suggest, some hot glue and contact cleaner (alcohol).
If not, then that power distribution card needs replacing.
But, I can tell you its a lot easier to replace the whole back section. There is a guy on ebay selling the whole back for $90 with cables and all. I bet you replace that section you wont have any problems.
Thats should do it.
I get about 24hrs at a time out of mine just lifting it up and playing with the cables. Im too lazy to replace the back section....actually, its been a busy week. Might do it tmrw.
But the fix usually last as long as you keep the board on (cirucit hot).