Paul Marossy Posted August 23, 2005 Report Share Posted August 23, 2005 OK, I have an ART SGX-2000 and the X-15 foot controller. For some reason, the foot controller will no longer switch banks. But everything else on the foot controller functions as it should. I have verified that my MIDI cables are good. So, that means that there is either a problem with that section in the SGX-2000 or the X-15. The schematics are a little complicated for me, though. Can anyone help me narrow things down on where to look?! SGX-2000 Schematic X-15 Foot Controller BTW, SW-2 & SW-9 on the X-15 schematic are the ones that are supposed to control the banks up or down. Both of those little tactile switches appear to be functional as well... Any help much appreciated! Quote Link to comment Share on other sites More sharing options...
ansil Posted August 24, 2005 Report Share Posted August 24, 2005 hey paul my guitarist had a similar problem some time ago. art suggested that the software might be old and to enter a patch [i dont' konw where to find it anymore but i will call him for you and see if he knows] Quote Link to comment Share on other sites More sharing options...
Paul Marossy Posted August 24, 2005 Author Report Share Posted August 24, 2005 (edited) hey paul my guitarist had a similar problem some time ago. art suggested that the software might be old and to enter a patch [i dont' konw where to find it anymore but i will call him for you and see if he knows] ← Hmm... I hadn't thought of that. Maybe "Y2K" actually happened to this unit?! Anyhow, yes please, let me know what you find out! EDIT: I had that foot controller sitting in my closet for years. The bank switching never seemed to work right, though. I've had the units since around 1994. Edited August 24, 2005 by Paul Marossy Quote Link to comment Share on other sites More sharing options...
Paul Marossy Posted August 24, 2005 Author Report Share Posted August 24, 2005 The problem appears to be narrowed down somewhat. Last night I checked the continuity of all the interconnective wiring, MIDI jacks, and if the tactile switches work as they should - I found nothing. However, SW2 & SW9 share a bus line called KSCAN-7, along with two other switches, SW6 & SW13 and none of these switches appear be operational. I am guessing that there is either a problem with the common connection(s) between these switches, U6 is faulty or there is something wrong with the +5V power supply to those particular switches. I also thought of two other things: 1. what if the LED on SW6 or SW13 burned out? Would it freak out like this? 2. What if the lithium battery in the main unit was dead? Would it have any affect? If I don't find anything fishy tonight in the X-15, I guess I'm going to do a factory reset on the SGX2000 and see if that helps any. I already did the factory reset on the X-15. Quote Link to comment Share on other sites More sharing options...
Paul Marossy Posted August 25, 2005 Author Report Share Posted August 25, 2005 Well, I messed with it some more last night, and I can not find anything wrong in the X-15 with the switches, continuity between them or the power supply - I thought I was onto something a couple of times, but it turned out to be nothing. I did a factory reset on the SGX2000, too. As far as I can tell, the LEDs are all functional (none are burned out). I do know that the lithium battery in the SGX2000 is most likely dead. I don't know if it could affect the operation of switching banks, but I guess I need to change it since it's been in that unit probably since 1992! I'll try changing the battery and see what happens. Quote Link to comment Share on other sites More sharing options...
TenderSurrender Posted August 26, 2005 Report Share Posted August 26, 2005 I guess the battery in there is like the battery in a computer, it just keeps track of any user specific settings you might chuck in there, but i couldnt see how that would effect the bak switching... Hope you get it working soon though dude ~~ Slain Angel ~~ Quote Link to comment Share on other sites More sharing options...
Paul Marossy Posted August 26, 2005 Author Report Share Posted August 26, 2005 Well, I am sort of out of ideas at this point, but I think it may be something to do with U6 or possibly something that controls the LED display on the X-15. I used the MIDI event viewer thing on the SGX2000 and buttons SW2, SW6, SW9 & SW13 all do not do anything - at all. So, I can't even do a factory reset on it because the up button has to be functional and it isn't! Also, the MIDI controller number SW7 (Pad 4) is stuck on 120 and it should be 73, and I can't change it! I'm thinking that this thing may not be repairable, at least not with my level of knowledge on this stuff. U6 (and U9) is a 74HC244 Octal 3-state buffer using CMOS technology. Maybe that thing took a hit somehow and that section of the chip that is associated with KSCAN-7 don't work anymore. I did notice tonight that it used to show whatever preset it was on before - one of my own patches was #128 and I used it a lot, but now it doesn't do that anymore. I also got a new BR2325 battery, but it didn't help. And the old one measured still measured 3V. Here are the other IC chips: U7 is a logic gate. U5 is a serial access EEPROM chip U3 is an 8-bit microcontroller U2 is a SOIC Octal "D Latch" U1 is a EPROM chip U4 is a standard logic IC U8 is an photocoupler This is kind of frustrating because I feel that I could fix it, I just don't know how to identify the source of the problem. Dammit Jim, I'm not a digital man, I'm just an analog guy! (think original Star Trek) I'll come back to it again, there's only so many things it could be. The only thing that's not really replaceable is the EPROM chip... Quote Link to comment Share on other sites More sharing options...
TenderSurrender Posted August 26, 2005 Report Share Posted August 26, 2005 U6 (and U9) is a 74HC244 Octal 3-state buffer using CMOS technology. Maybe that thing took a hit somehow and that section of the chip that is associated with KSCAN-7 don't work anymore. I did notice tonight that it used to show whatever preset it was on before - one of my own patches was #128 and I used it a lot, but now it doesn't do that anymore. I also got a new BR2325 battery, but it didn't help. And the old one measured still measured 3V. Here are the other IC chips: U7 is a logic gate. U5 is a serial access EEPROM chip U3 is an 8-bit microcontroller U2 is a SOIC Octal "D Latch" U1 is a EPROM chip U4 is a standard logic IC U8 is an photocoupler This is kind of frustrating because I feel that I could fix it, I just don't know how to identify the source of the problem. Dammit Jim, I'm not a digital man, I'm just an analog guy! (think original Star Trek) I'll come back to it again, there's only so many things it could be. The only thing that's not really replaceable is the EPROM chip... ← Well im not going to pretend to understand that so ill just wish you good luck finding the problem dude When fixing pc's i know how frustrating it can be to try and identify the problem especially when you can almost guarantee you can fix it once you know what it is Anyway like i said, good luck dude ~~ Slain Angel ~~ Quote Link to comment Share on other sites More sharing options...
Paul Marossy Posted August 26, 2005 Author Report Share Posted August 26, 2005 i know how frustrating it can be to try and identify the problem especially when you can almost guarantee you can fix it once you know what it is YeAh, I kNoW! Thanks for the well wishing. Quote Link to comment Share on other sites More sharing options...
crafty Posted August 26, 2005 Report Share Posted August 26, 2005 Do you have a logic probe? Quote Link to comment Share on other sites More sharing options...
Paul Marossy Posted August 26, 2005 Author Report Share Posted August 26, 2005 Do you have a logic probe? ← No. Got one I can borrow?! If I did have one, what would I need to do? Quote Link to comment Share on other sites More sharing options...
Paul Marossy Posted August 26, 2005 Author Report Share Posted August 26, 2005 WOO HOO!!! Good news, it's fixed! I removed U6 and U9 put a socket in their place with new 74HC244s, and now it works. I am really happy about this!!! Ahem, anyways, thanks for the help. Quote Link to comment Share on other sites More sharing options...
crafty Posted August 27, 2005 Report Share Posted August 27, 2005 If you had a logic probe, you could've troubleshooted those bad ICs in about two seconds: Wavetek Logic Probe on Amazon It's a nifty little device that tells you whether a gate is open or latched. So if you'd hit one of your footswitches, if the little logic indicator on the probe didn't change or you don't get any signal at all, chances are that IC is bad. It's a good tool to have, I received mine for free (as in beer) back in my vo-tech days for winning an electronics competition. Now that I've long forgotten all that stuff, it's been very useful gathering dust for 8 years. But at least I know if I need it, it's there! Quote Link to comment Share on other sites More sharing options...
Paul Marossy Posted August 27, 2005 Author Report Share Posted August 27, 2005 Well, I never needed a logic probe before, but I'm thinking it might be a good thing to have for future use! Quote Link to comment Share on other sites More sharing options...
crafty Posted August 28, 2005 Report Share Posted August 28, 2005 (edited) Yeah, when you get into stuff that uses simple logic ICs, then it's an immeasurable help. Just about anything like that is going to have some sort of 7400 logic in there to control patch changes and other controls, even in new "processing" pedals like the Digitech Crossroads. Now dealing with microprocessors, that's a whole 'nuther can 'o worms, and better left to the recycling bin in my opinion. Edited August 28, 2005 by crafty Quote Link to comment Share on other sites More sharing options...
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