Bumply

Two 6582A SIDs are installed I'm using a TRS-TRS cable When I send the sammich output directly to balanced stereo input - the focusrite saffire pro 40, for instance - I experience the problem where the patches listed by the OP are very quiet. When I either use a TS cable or run a TRS into an unbalanced unit (like a guitar amp), the quiet patches are now at normal volume. The poly patches now play only half their voices. So I'm am led to believe that one of my SIDs is damaged. Is this a correct assumption?

Hi all...I haven't had a chance to open up the sammich and try to diagnose the problem. But this might be a clue. This morning, I ran it through a guitar pre-amp and found that all of the quiet patches are now at normal volume. However, the poly patches and drum sequence patches only play half the voices. Any thoughts about this?

I'm going to jump into the thread. I'm experiencing the exact same issue. I failed the filter test, and in the osc test i get sound from all the waveforms but saw, traingle and pulse.

A quick bump to this thread..hungry for sammich.

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.

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

Bit of a noob question, but how do I go about check the connections between the PIC and the LCD header?

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.

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

Apologies, I was a bit rushed. I meant the LED's flicker.

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