...back to the drawing board... When unplugging the data bus connection at the DCO circuit, all the randomness stops and all the leds light up steady. I'm not sure if this means anything yet but I'm looking into it. I tried looking at the SX240 service manual stored here and the schematics are almost illegible on my computer, but it looks like there are two processors controlling everything. Page 41 explains the functions of each, in case you haven't already looked at it. When you say it seemed like the synth worked well, do you mean it makes sound? Because mine doesn't do anything, just the random flashing of lights and display. If I hit a key it stops though, and the leds that were on go steady. After looking at the differences between the 210 and 240, I'm not really sure if the same problem is plaguing both of our synths, but I could be wrong. They are a lot more different digitally than I had imagined. Jeremy Dearing --- In Kawai-Teisco@yahoogroups.com, Ullrich Peter <peter.ullrich@...> wrote: > > Hi! > > Normally the 8051 should also be able to boot from external memory as the 8031. > It depends on the #EA/VPP pin (external access). It has to be connected to GND for external access. > > See datasheet page 7-47 (http://www.datasheetcatalog.org/datasheets2/10/1046235_1.pdf ) > > Ciao > Peter > > http://www.ullrich.at.tt > http://go.to/datadial (Synth addon for many synths - also Kawai K3/K3m for example) > ________________________________________ > Von: Kawai-Teisco@yahoogroups.com [Kawai-Teisco@yahoogroups.com] im Auftrag von jdearing17 [jdearing17@...] > Gesendet: Dienstag, 24. Juli 2012 02:14 > An: Kawai-Teisco@yahoogroups.com > Betreff: [Kawai-Teisco] Re: Kawai SX240 Problem > > Update: ROM switcheroo did not help, unfortunately, so on to the processor. I talked to an engineer I work with and I told him that the service manual and the tech at Kawai said the chip should be a 8031, but there is a 8051 there instead. Thought this was kind of weird, but maybe someone's worked on it before? There isn't much evidence of that, but it could be. Anyway, the 8051 is the same pinout as an 8031 but the 8051 has onboard ROM that it boots from. He explained to me that the 8051 may not be able to boot from external ROM while the 8031 relies on it. > > So Friday I go to his house and try to find an 8031 somewhere in the pile of junk in his garage. > > BTW, I backed up my ROM to a binary if anyone needs it, I uploaded it to the files section. > > Jeremy > > --- In Kawai-Teisco@yahoogroups.com, "jdearing17" <jdearing17@> wrote: > > > > > > > > I cleaned up all the traces, replaced them with solid wire where necessary, used water soluble solder and flux and washed the crap out of it. Then I took a meter and made sure I had continuity at all points, replaced the 3.6V battery with a 3V lithium (which I'm hoping is enough, but all it backs up is patch ram as far as I can tell, so nothing critical.) > > > > The battery took out my ULN2003 chips and the battery charging circuit. I'm thinking about redesigning the mainboard with smt components and a higher quality circuit board, but the SX210 is sort of a side project for me as most of the time I'm "wasting" my time adjusting harmonic levels on my K5m and K5000s. By the way, the K5m isn't notorious for battery leakage but mine was leaking, nothing damaging, fortunately. Got it before it could kill anything. That synth is quite a bit more complicated in it's digital circuitry. My R-100 still has it's original battery and I know, it's a ticking time bomb. > > > > The processor on the SX-210 responds to a reset, so I'm guessing that it's working properly. > > > > And if you need chips talk to Kent Smith at Kawai, his extension is on http://www.kawaius-tsd.com/pages/contact.html > > > > By the way picked up the chips from my parent's house today (I had ordered a K5m 1.2 ROM as well.), I'm going to make a backup of them before installing them just in case (the chips aren't proprietary, standard EPROMs). I'll post my results later this week. > > > > Jeremy > > > > --- In Kawai-Teisco@yahoogroups.com, w.james.meagher@ wrote: > > > > > > When you replaced the components did you also fix all the eroded traces on the PCB around them? Also, it's very important when you do this that you clean that whole area of the PCB thoroughly, or it will continue to erode over time. > > > > > > James > > > > > > Sent from my iPhone > > > > > > On 2012-07-22, at 10:36 AM, "jdearing17" <jdearing17@> wrote: > > > > > > > > > > > > > > > Hi, I am having this problem with an SX-210 as we speak. Unlike yours I had pretty bad battery leakage and had to replace 4 or 5 components on the corner of the mainboard. After doing that I could get the interface to sort of do something, but I still couldn't get it to respond to the "panel check" command. I've got a ROM chip coming from Kawai because it was cheap enough, I'm just waiting for it to come in the mail. I'll let you know if that fixes it. > > > > > > > > Jeremy > > > > > > > > --- In Kawai-Teisco@yahoogroups.com, "Paulo" <panorphelia1986@> wrote: > > > > > > > > > > Hi > > > > > > > > > > I got a broken Kawai SX240 a while ago. > > > > > > > > > > As I plugged the synth, I found that the interface doesn't seem to be responding at all. > > > > > The lights turn on randomly, the buttons don't seem to work, the display shows strange symbols and the keys don't produce any sound. > > > > > > > > > > I took it to a tech (who "unfortunately" is more expert on guitar equipment than keyboards/synths) and after checking the synth with me, he suggested it could be a problem with a proprietary chip of the synth (maybe a corrupt OS chip?). > > > > > But as he was checking the synth, he unplugged some cables and it seemed like the synth itself works well, so hopefully it is just an interface problem and nothing more. > > > > > > > > > > Anyone had the same problem? > > > > > And are the proprietary chips on it impossible to find, or it might be possible to repair? > > > > > > > > > > > > > > > Thanks in advance, > > > > > Best > > > > > > > > > > Paulo > > > > > > > > > > > > > > > > > > > > > > > ------------------------------------ > > Yahoo! Groups Links > > > > confidential and is for the exclusive use of the addressee. The person > who receives this message and who is not the addressee, one of his > employees or an agent entitled to hand it over to the addressee, is > informed that he may not use, disclose or reproduce the contents > thereof, and is kindly asked to notify the sender and delete the e-mail > immediately. >
Message
Re: Kawai SX240 Problem
2012-07-25 by jdearing17