I just don’t know anymore…

[Edpoiloo]

Hello all,
I’m new here. Ok so, I bought a Korg ms2000r at a flea market [cheap]. At first when I would turned it on, all the lights would light up, the LCD would come on [LCD characters too], I could scroll through the menus, I could press the keyboard keys and they would light up, everything seemed ok ‘cept for the fact that there was no audio output at all, from either the headphones or the audio jacks. I could still run the tests suggested in the service manual, so I did, and I would get the “midi loop check timeout err!” Message. So, I looked all over the internet, for answers. It was suggested that I should connect a midi cable, from ms2000r’s output to its own input. So, I purchased a midi cable [which will get to me, in about +/- a month, if I’m lucky]. In the meantime, I decided to have a look inside this thing. I got some ESR values of the SMEs, I looked for broken traces/tracks, burnt marks, etc, etc. Throughout the tests, I would then turn on the ms2000r to see if anything had changed but nothing did - still no audio. So, I pulled out a logic probe and mindful not to bridge any pins on the various chips, I started poking around. Results from the probe were inconclusive [I’m still just a hobbyist, at this] but since then, when I turn on the ms2000r all I get is the two LEDs at the audio in turning on green [for an instant] then turning red, before going off, and the only other light left on this synth, is the backlight of the LCD screen [without any characters at all] and of course- still no audio. Could I have accidentally tugged on the big ribbon cable? Did I accidentally corrupt some chip with the logic probe [it’s a passive device, I right?]. I’m out of my depths here folks. Any insight would be greatly appreciated. Thank you kindly, in advance.