Hi All, I have an Alesis QS6 with motherboard Rev B 6-21-95 that has lost sound from the keys (upper and lower). Initially, the problem began as not having any sound form keys after power up. But, I could use the standard reset 0 + 3 combo and it worked just fine and I got sound back and did this for a while but figured it was time to change the battery (sometimes the LCD display would just be blank green, sometimes not, but still produced sound).
So I changed the battery and now there is no sound from the keys and the standard reset 0 + 3 does not fix the problem. The demo will play fine and, I can hear the normal low level scratchy noise of the volume fader in the output so the audio out section seems fine. I also tried loading new SYS files via midi input from computer to restore factory files but that didn’t fix the problem either. I’ve also pored over the MB front and back looking for broken traces or cracks and bad solder joints and reseated all the connectors that weren’t glued down with sili-goop. I checked the new battery connections on the underside of the MB and can measure the battery voltage just fine. I confirmed proper voltage at the lone socketed IC, but am hesitant to try and check voltages on the Key Scan ASIC chip for fear of shorting the pins with the meter probe. I also can’t find standard test points labeled TP so I’ve hit a brick wall after 17 hours of troubleshooting over two days and was wondering if anyone had any suggestions on how to narrow the problem down..
Maybe try a new Lithium battery and make sure it’s inserted correctly not upside down. If you’re getting a scratchy volume slider or knob, that definitely needs to be sprayed with Deoxit D5 spray. You can purchase the Deoxit D5 spray from Sweetwater Sound online. Before you spray the scratchy sounding volume, remove the plastic slider control cap or knob’s plastic outter cap. You need to spray it and move the slider or knob up and down or left to right all the way about 30 times. Let it sit for 20 minutes. The Deoxit spray will seep into the crevices and remove the oxidation as well as lubricating it’s inner section making it feel smooth when you adjust the volume. It just needs a short quick spray, Just like “Tss -Tss”, Make sure your power is disconnected and the synth is turned off when you spray. Wait 20 minutes, turn it on and check for anymore scratchy type sounds by moving the volume constantly from low to full volume. Sometimes you need to repeat the spraying, 30 times rotation of volume and wait another 20 minutes before reconnecting power to re-test the results. This should work easily for that issue. Also check on a factory reset. Sometimes after changing a Lithium battery, on a synth or sound module… you have to hold down specific buttons while turning on the power for a full factory reset. I’ve done this on my Yamaha DX-7, Roland JP-8000 and Korg SR Wavestation. All the machines had to be factory reset after changing their dead Lithium batteries. They each made no sound and blank display on Korg SR-Wavestation module until I held down specific buttons while turning on power. Check online to make sure you are resetting it properly and holding down the correct buttons. If you do this correctly it should work 100%. If you do it correctly and still have a blank display, you may need to replace the LED Display to a new one that you can probably find on Ebay. Also, check your power supply board, specifically the capacitors. If you have any leaking capacitors that could be the problem. It happend on my Ensoniq ASR-10 Keyboard. Turned it on one day and the display showed an error message. It wouldn’t boot up. Then absolutely no power at all. The problem was old leaking capacitors on the power supply board. So definitely check that with your power cord unplugged. Make sure you touch some metal to discharge any static electric from your hands before opening it up and touching the capacitors. The note for capacitor replacement is: you can put in more powerful ones but not under powered ones. I hope this info helps.