Posted by paul on November 27, 2006 at 12:07:03:
In Reply to: Re: Repairing a QS8: CALLING ALESIS TECHS! posted by james watts on November 11, 2006 at 09:11:44:
: : Reid, I have a QS6 that's doing the same exact thing. Could you please e-mail me and correspond? This gives me hope that it's saveable. I'm also a tech (with 30 years of experience.) I'm Narfman96 at yahoo dot com. I'm also the owner of the Alesis QS Synthesizer Yahoo group.
: : : Hi, Ben. Thanks for answering.
: : : I've discovered one broken address trace on the bus, and one other open pin on one of the chips. I'll try soldering jumper wires on those and see what that does. One other surprising thing I found (the hard way) is that the 7805 regulator's heatsink gets painfully hot, but I've been informed by a former Alesis employee who worked on this unit that that's normal. Sure enough, the datasheet says its rated for up to 125C, and it feels like it's damned near boiling! I didn't try a spit-test. :)
: : :
: : : BTW, I've seen your great web page, and I'm going to try programming a couple of cheap flash cards I picked up on ebay. I got one for less that $7 US, with free shipping! I'll report my results.
: : : Thanks again.
: : : Reid
: I guys, I'm not a computer tech but a musician. I have owned a QS8.1 for ten years. Recently it is starting to distort on both sent channels. What do you suggest I do? I do get a clean sound when I play through the head phone jack!
: Any help you could suggest would be gratly appreciated.
Trying to repair one too. problem with the main and aux outs. very low level on the outs. but the headphone out works. James check out the 4 transistors by the 1/4 inch jack sockets. i think they are the problem. i just took them out and im getting the proper level on the outputs, but they must be there for a reason so im trying to find replacements before using the synth properly. they are marked P724CD. I also don't have a schematic, does anybody have one? i reckon they are doing some sort of current limiting/ buffering dont really know.
good luck and if i fix it i'll post here