Bumply Posted March 12, 2011 Report Share Posted March 12, 2011 (edited) Argh! So, everything was looking good, ready to load in the MIOS. Using a 12v unregulated, 500ma power supply, with 6581 Sids. All the voltages checked out fine. Installed the PIC18F4685, 74HC595's, 74HC165's. Left the bank IC's and the SID's out per the build guide. Powered everything up. LED's flash on. LCD opens up to something like "MIOS by Franz", or something of the like. Plugged into the midi jacks to get the operating system set up - strange behavior ensued. Turned off the Sammich. Turned it back on, the LED's flickered and the LCD was darkened. Turned the trimpot counterclockwise and got the squares. I checked and rechecked the voltage. Took the IC's out, put them back in. Checked solder joints. Made sure the shunts were placed correclty. At one point, turned it back on, and a few of the LED's came on. The next time, none of the LED's. The LCD display continues to be the squares. I wondered if this had something to do with the midi in connector, which was very sticky/tight and I had to force the midi cable a bit. Wonder if I knocked something around. It seemed like the problems began when I was using midi cables. Appreciate any help. Matt Edited March 12, 2011 by Bumply Quote Link to comment Share on other sites More sharing options...
Bumply Posted March 12, 2011 Author Report Share Posted March 12, 2011 Apologies, I was a bit rushed. I meant the LED's flicker. Quote Link to comment Share on other sites More sharing options...
Wilba Posted March 13, 2011 Report Share Posted March 13, 2011 Using a 12v unregulated, 500ma power supply, with 6581 Sids. NO! You need REGULATED 12V DC for 6581 SIDs. Certainly I've made this clear in the build manual. You should also not have inserted 6581 SIDs unless you get exactly 12V on the points marked 12V. Seems unlikely to have happened with unregulated power supply. Most likely your other issues are due to too much current load, causing the internal voltage regulator to fail, causing the PIC to sometimes not boot and/or other stuff not working. Remove SIDs immediately. Get everything going again WITHOUT SIDs. Get a regulated 12V DC power supply, preferably more than 500mA (to be sure) but a 500mA one will work. Also turn down the LCD backlight brightness to half-way or less. This reduces current load, so when SIDs are eventually put in, you won't go over 500mA. Note SIDs each take 100mA on the 5V supply! So to balance it, the LCD should be drawing ~100mA to keep it all around 300mA or so. Quote Link to comment Share on other sites More sharing options...
Bumply Posted March 13, 2011 Author Report Share Posted March 13, 2011 Thanks for the reply. Ok. My mistake. It is regulated - I'm just not very precise with my words. The voltages checked out fine (12v) all along. But to be safe, I'll purchase another one (more than 500ma) from recommendations on the forums. Meanwhile, in all my fiddling, I've managed to break the leads off of 2, 74HC595's. So, I'll need replacements. I googled searched and came up with a few. Would any of these suffice?: http://www.sparkfun.com/products/733 http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&pa=46105&productId=46105&keyCode=WSF&CID=GMC Thanks Wilba Quote Link to comment Share on other sites More sharing options...
Wilba Posted March 13, 2011 Report Share Posted March 13, 2011 They should work. For reference, I use Mouser part 511-M74HC595. Quote Link to comment Share on other sites More sharing options...
Bumply Posted March 19, 2011 Author Report Share Posted March 19, 2011 An update from my last post in this thread. I purchase a 12 volt, 1000ma regulated ac adaptor. Replaced the 595 sockets. Ran all the voltage tests without an IC's, and everything checks out. Installed the PIC18F4685, 74HC595's, 74HC165's I have a shunt in at 12v, and on JR4 When I power up, I get the rectangles on the LCD. Occasionally, a pattern of LED's will light up - but never all the LED's. At one point, more of the LED's lit when I tightened one of the screws holding the LCD in place, but more adjusting had no effect. The only thing that may be an issue is that i purchased a shunt from Radioshack which is placed on the SID 6581 area, which has an 'open top'. Because this doesn't seem to be an issue with the power supply, I'm wondering if some of the solder joints are poor, but not sure which joints might be a problem. Any help would be greatly appreciated. Quote Link to comment Share on other sites More sharing options...
Wilba Posted March 20, 2011 Report Share Posted March 20, 2011 If you are not getting text on the LCD (i.e. only "black bars") then that's the first problem you need to fix. The PIC has MIOS installed so you should get the MIOS boot screen. Check the connections between the PIC and the LCD header, solder joints on both ends of the LCD header, etc. It might help to remove the LCD from the CS PCB so you can resolder the joints without the CS PCB getting in the way. Perform continuity tests on all the pins of the LCD header, both ends, check there are no adjacent pins which are shorted, etc. Also, check that you are getting some MIDI output, i.e. the single "upload request" sysex message... or just use MIOS Studio 2 and query the sammichSID (you need both MIDI In and Out connected and MIOS Studio ports configured correctly)... it should report that MIOS is installed on the PIC. This will help validate that your PIC is running and should be sending data to the LCD. Quote Link to comment Share on other sites More sharing options...
Bumply Posted March 20, 2011 Author Report Share Posted March 20, 2011 Bit of a noob question, but how do I go about check the connections between the PIC and the LCD header? Quote Link to comment Share on other sites More sharing options...
Wilba Posted March 20, 2011 Report Share Posted March 20, 2011 I've been very slack and never got around to uploading the PCB layout PDFs to assist with troubleshooting. I guess 95% of the time, I diagnose what's wrong and people just fix their solder joints or replace parts put in the wrong way :wink: The troubleshooting section of the wiki now has PDFs: http://www.midibox.org/dokuwiki/doku.php?id=sammichsid#sammichsid_troubleshooting So now you can see which tracks lead between the PIC and the LCD header. There are 4 data lines and 3 control lines, all on the top layer (red). Quote Link to comment Share on other sites More sharing options...
Bumply Posted March 20, 2011 Author Report Share Posted March 20, 2011 Ah, those PDF's are great. Here is my update. Still no luck... 1. Ran continuity tests to check connections between PIC and LCD header. All of the seven bands at the top row check out fine. I removed the MIOS IC, placed one end of the multimeter in the socket, and the other on the flip side of the board, on the soldered joint. All the red lines connect. 2. Resoldered both sides of the LCD header. Resoldered MIOS IC socket for good measure. 3. Ran continuity tests on LCD header...no shorts. 4. Checked MIOS studio. With correct ports, etc, I get the error message...no response. Get the rectangles, to LED's. Given that there was a point when the boot screen came up, and all the LED's powered, I'm wondering if the MIOS IC got fried...something seemed to just go wrong. I could swear I was using a regulated 12v, and all the voltage checks were consistent prior to installing the IC. The only error I made along the way was placing one of the 595 IC sockets backwards, something I removed and fixed. Everything worked fine after that error. Hmmm. So what next? Purchase a new MIOS IC? Thanks again for your help Quote Link to comment Share on other sites More sharing options...
Bumply Posted March 20, 2011 Author Report Share Posted March 20, 2011 Another interesting symptom... When powered, laying flat, the LED's do not light up. If I pick up the sammich and rotate slowly until it faces downwards, some LED's will light up and go off intermittedly - there is nothing consistent about this, sometimes they light up, and sometimes they do not. Strangely, I remember all of the LED's lighting up prior to the MIOS failing to boot. Quote Link to comment Share on other sites More sharing options...
Bumply Posted March 24, 2011 Author Report Share Posted March 24, 2011 A quick bump to this thread..hungry for sammich. Quote Link to comment Share on other sites More sharing options...
Wilba Posted March 24, 2011 Report Share Posted March 24, 2011 It sounds like there are multiple things wrong, which is hard to diagnose and fix remotely :wink: The easiest and quickest way to get this going again would be to send it back to me so I can swap out things like LCD, PIC, other ICs, etc. (and test your parts in a working sammichSID). Then anything not working I can replace straight away. Quote Link to comment Share on other sites More sharing options...
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