Wilba

The outer pins on JBL are 5V and 12V respectively. Putting a shunt in the left or right position will connect either 5V or 12V to the middle pin, which is connected to the backlight. It may not be exactly 12V on the 12V pin, as it is actually the input voltage, after passing through the bridge rectifier, so for unregulated PSUs it will vary with load. Blocks on the LCD have nothing to do with the backlight working or not. They indicate the LCD is being powered by 5V (on a different pin) but not receiving the right data to initialize and display characters. You will need to check the connections on the headers and the LCD and PIC pins to which they connect.

LOL those switches were then connected to digital inputs that were then not connected to either a high (5V) or low (0V), just floating and being whatever they liked. They were then connected to 0V when the switch was pressed, but when not pressed, random garbage. Don't solder the 22nF caps. Those sockets are so you can swap the caps to match the SID type, or use different caps, not that you are likely to do that.

Does the synth itself stop playing notes, or just the LCD doing strange things? IT could be just the LCD, so check the connections, solder joints on the LCD pads, the headers, the PIC, etc.

I can send you spare button caps. How about we wait until everything is working, I might need to send you some other parts. If ALL your switches and encoder aren't working, then it could be some problem with the shift registers. Check the resistor networks are soldered the right way, with the dot on the resistor network matching the dot on the PCB. If correct, you should only see the dots on two of them, the other two will be on the side next to the IC and hidden. I suspect the problem might be with the headers, though... since you just had a similar problem with the LCD. A bad connection there and you won't get correct data in or out. But essentially you'll need to check joints everywhere... on the ICs, the resistor networks, the switches and the headers, and then even on the PIC where the header pins connect. You don't need to solder the switches from the top, the holes are plated, so it's connected to the tracks on the top layer. Try the CS test app, found on the wiki page under "sammichSID Troubleshooting" That should give you an idea if the problem is specific to some switches or all of them.

I didn't pay attention to the same-day new membership and post count of 1. Now my post smells like spam too. Ooops.

A friend of mine wrote an iPad app called Instrumental It's a great way to integrate an iPad into music production.

If any of the pins on the LCD header have shorts or are poor solder joints, then the LCD may not get the correct initialization data and so nothing will display. So you should check continuity between pins on the bottom of the PCB with pins on the LCD header... and then also check that there are no pins shorting. You should ALSO test where those pins connect to the PIC... a bad solder joint there (or short) will cause the same problem. Refer to the PCB layout PDF in the wiki: http://www.midibox.org/dokuwiki/sammichSID to find out which PIC pins connect - they start at pin 1 and go down the "right" side of the PIC. Since I test all the LCDs and you apparently can see the rectangles, it's a good sign that the LCD isn't dead, just not receiving the right data.

I have a nice collection of all seppoman's PCBs that I never seem to find time to build and use. I even feel a bit guilty that he also helped me out with a lot of the trimpots, styro caps and miniature relays for the SSM2044 board as well. Soon I'm going to ruthlessly sell off stuff I'm not likely to use... so someone please remind me if it gets to 2012 and I haven't done a big virtual garage sale of electronic bits :wink:

It seems like 9 out of 10 problems with a sammich* are due to bad solder joints/shorts. Thus if it doesn't work, it's probably your bad soldering! just sayin... :wink:

sammichSID Final Batch! No, seriously, I mean it this time! Yes, I know I said this when I'd sold 350 kits, but I kept getting orders and kept making kits, because I hate saying no to people. Now the total is 500 550 kits sold, and I have got to the end of the waiting list, and I really, really must stop sometime and do something else! There will be a final batch of 50 kits in January 2012 (or when I get 50 orders). There are still plenty of kits available in the final batch, and any extra pre-orders I receive will go on the waiting list, just in case I change my mind and do another one-off batch next year. Like last time, I fully agree this is some shameless self-promotion to boost sales so I can finish with my routine 50 kit batch and sell off all the PCBs and parts I have in stock. If you're interested in getting a sammichSID, or want to find out WTF this thing is, all the information is here: http://www.midibox.org/dokuwiki/sammichsid Regards, Wilba

@Tim B: where are you? I have dozens of spare LCDs of various sizes that I can give away for free... it just depends on what you want to spend on postage.

One thing to consider: PIC18F4685 only outputs in 4-bit mode, and some (most?) LCDs won't work in 4-bit if you've connected up all 8 data lines. So check if you are using PIC18F4685 and use this wiring instead. http://www.ucapps.de/mbhp/mbhp_lcd_4bit_mios8.pdf You are correct though, if the data lines are not correct, the LCD won't receive the correct commands to initialize or display characters.

Can't you design what you want with some other program (like Inkscape) and then type in the co-ordinates for each LED? I'm not an Eagle user, but that's what I did with another crazy idea I had recently, arranging LEDs according to Fermat's spiral, just made a spreadsheet to calculate the coordinates I wanted and then copy/pasted into the component's coordinates.

Since the cable is less width than normal, you should be able to separate the wires using a craft knife and push them individually into the "fork" contacts of the IDC header, maybe just enough so they are all lightly gripped by the "forks" and nicely aligned, and then clamp them in properly with the other part of the header. In other words, space out the wires to suit the standard IDC header. If you then fold the cable around and use the "stress relief" clamping part as well, then there should be no problem with wires moving. Slightly off-topic: I vaguely recall seeing a fat ribbon cable between two IDC headers that had one pair of wires split from the rest and twisted around. Maybe it was inside an old PC or something.

It looks like you're in Germany... so I recommend posting the "distorting" sammichSID to nILS (also in Germany). I'll pay the return shipping. I think a second pair of eyes will help in this case. It certainly sounds like it's a fixable problem, just what to fix is elusive. Email me to discuss the details.

OK so if you routed left SID socket to right SID audio buffer (that's the caps and BC547 between the SID and the audio socket) and both channels sounded the same (distorted), the problem is to do with the left SID socket only. I don't understand what you meant by "it sounded OK again", I thought the problem was always with the left SID socket??? My best guess at the moment is that the filter caps, the machine pins for the filter caps, or some other solder joint in/around the left SID socket is the cause. You could try replacing the machine pins just in case the contacts with the filter cap leads are poor... maybe something got stuck inside them, or they are faulty, tarnished, etc.

Just a note on what Imp said: external input is already grounded by the audio in socket so there's no need to ground it more. Since you swapped SIDs and the problem stays with the left socket, it could be either the solder joints for that SID and audio buffer, or perhaps something wrong with the firmware - i.e. the ensemble's filter range for the left SID is different to the right. So check the ensemble for anything different between left and right SID. You say you checked the filter cap sockets, but check also the SID pins they connect to. You could try routing the left SID's output to the right SID's audio buffer - remove the right SID and connect a wire between IC1L pin 27 and IC1R pin 27. Thus the left SID's audio output will go through the right SID's audio buffer and you should get identical sound on both outputs of the audio socket. If they don't sound identical (i.e. left channel distorts early, right channel does not) then you've isolated the problem to the audio buffer. You can then try taking out the left SID and inserting the right SID, do the same wire to test the right SID with the left SID's audio buffer. (I bolded the "taking out" part because you don't want to directly connect SID audio outputs!)

This could be just a bad solder joint on the header to the LCD. So I would recommend checking all the solder joints on the female header and perhaps even disassemble the LCD from the control surface PCB and give all those pins a check and reheating. It could even be caused by bad solder joints on the PIC pins leading to that header, so check those too. It would be good to confirm that it's JUST the LCD that is the problem and nothing else... so if you get garbage on the display, check if the sound engine is still working... i.e. send it note events while it's displaying garbage. FWIW: MIOS has a "feature" that if it sends LCD commands and then waits too long for the "busy" state to finish, it disables the display completely. It might think the LCD is "busy" if the command was garbage, or retrieving the busy state is returning garbage, which can happen if one of the data pins is intermittent. So it's not a surprise if sometimes the display "locks up".

I'm not an expert with 6581, but from those I've sampled, they all make some sound when the gate is off, but some are louder than others.

If you put shunts in JBP then the input power must be tip positive. So check that first. Basically shunts in JBP just bypass the bridge rectifier so all points that are "12V" are identical (electrically connected) to the input power tip.

OMFG those sockets are awesome! If only I didn't solder boring sockets on my current base PCB.... I may have to build another one just to use these sockets. nILS, buy me 8 of them. Actually, make it 10... I should prove they are also awesome on sammichSID.

If "wimpy MIDI output" is the problem, then it would be the same for note on and note off events, so I don't think that's the problem here.

I forgot to add, to keep the current reasonable (100mA) and prolong the life of the LCD, set the brightness pot to half-way or less.

There are plans for future projects... but there's nothing to show yet... :wink: BTW I still have 15 sammichFM kits available.

This could just be the 6581 SID... the oscillators don't fully "gate off" properly, a known problem with this type of SID. Check that this effect is happening regardless of whether the note played is via external MIDI or by pressing the Play button (F1). Perhaps you can record what you hear and share it, then I could give a better opinion.