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[solved] Sammich Bank Sticks problem [bad PSU & solder work]


Shiftone
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Ok after finally getting my midi loopback to work and upload the sammich hex I've installed my banksticks (still no sids in and still using a switching 12v psu at the moment)

Now when I switch on the Sammich it seems to be endlessly formatting.

I've checked continuity between the bank sockets and the PIC and I've also checked all the voltages in the sockets. Nothing seems to be wrong there. I've reflowed the PIC socket and generally had a good look at the board for any obvious problems. I can't for the life of me work out where the problem is coming from and how to fix it..

Oh my CS tested fine before installing the bank sticks.

Edited by Shiftone
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It will go from Bank A to B to C back to A to D sometimes to ensemble - occasionally it gets back to the initial CS screen and then in a matter of seconds starts again...

In other news... I just reflashed the sammich hex and now its stopped endless formatting... but doesn't see any bank sticks at all... no other changes were made, just re-flashing.

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It seems that previously the bankstick read wasn't reliable, and now it doesn't work at all.

This could be related to a power problem, because while the PIC and maybe also your LCD works fine even in (unwanted) lower voltage ranges, the EEPROMs are more sensitive against this.

In order to check, if this is the case, it would be interesting to know if the SID chip outputs a sound, and if the filter is working (because on too low voltages the filter just mutes the sound, or has no effect - depending on the filter mode)

Best Regards, Thorsten.

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Update - got frustrated with it after reflowing the entire base board and still having the same issue and creating an entirely new issue - screen corruption!

Decided the best course of action was to box it and let both myself and my Metcal cool off for a few days. In the interim my proper 12v regulated 500ma power supply has arrived.

So I put my Sammich back together and added the banksticks - plugged in the new PSU and everything just worked - banks all formatted no issues at all.

Moral of the story - stop using naff switching psus to test after initial voltage checks.

I'll pop in some SIDs now and see if we truly have liftoff.

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Nope - no lift off.

So after the SIDs went in (8580R5x2) the Sammich would power up and report the MIOS version - flash the lights then the screen clears and nothing - Launching CS does not appear.

So I removed the SIDs and back up a step - but I am back to encountering strange corruption on the LCD (not as bad as before). The odd thing is, if I lift the PIC and go make a cup of tea - come back drop it back in I can generally get the CS to launch. It invariably gets worse with each successive power cycle and I have not yet managed to get it to work with SIDs in.

Is it possible I have a flaky PIC?

I've been back over the boards with a meter and voltages are spot on - not visible problems with shorts or bad joints.

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Incoming massive pictures

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I know that solder in the middle of the PIC looks aweful (I'm embarrassed of it) but it is making good contact and not shorting the pin next to it. I really should have used some leaded solder for this build - hate lead free

I just managed to get it to start up all the way to the default patch and the CS was responding as expected (with SIDs installed).

I hooked up the audio and power cycled - again started fine and I got the test tones out of the left SID but nothing out of the right (these SIDs are verified in a working C64)

After a little more testing (left right swapping) I still didn't get anything out of the right hand SID and the test tones have now turned into some puffs of white noise...

In an effort to see how much more I could break it - I powered off and inserted the MIDI cables (but did not connect the other ends to anything). Next start up things are getting decidedly worse - we're back to hanging at the bootloader or blank screen after the dancing LEDs.

Edited by Shiftone
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This has really go me baffled... so I pick up the sammich after leaving it alone for the night - plug it in with audio out connected to my amp but no MIDI cables connected.

The box boots fine and plays the start up sound (still only one channel though

So I power cycle a few times - and each time boots fine and sound out of one channel.

Things start to go down hill when I plug the MIDI cables in - first problem, the start up sound turns back into puffs of white noise... I connect to mios studio and re-upload the software. The upload appears to complete successfully.

Over then next handful of power cycles I experience the following problems;

puffs of white noise

oddness in the CS LCD menus - Like page changes without me pressing any buttons...

mios spontaneously rebooting

and then finally problems getting the midi interface to behave and be recognised in mios studio...

I'm fairly sure if I leave it alone for a couple of hours I'll be able to rinse repeat this whole affair... I wonder if my MIDI interface is the flaky thing and the software is not being uploaded properly? Or if I have a flaky octocoupler?

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  • 2 years later...

Epic thread resurrection....

 

Anyone care to have a look back over this thread and try to help again?

 

This Sammich got thrown into its box and chucked in a dusty corner for the last 3 years. Never managed to progress.

 

Well today I dug it out after feeling like the Gods of semiconductiors were smiling on me after restoring my Quad 303 amplifiers. I have to say this thing has got me totally baffled.

 

For the first 20 minutes or so of playing around with it - the constantly formatting bank sticks were nowhere to be seen.  The Sammich even responded to MIDI IN signals coming from my PC via a cheapo generic eBay special USB-MIDI cable and played notes using the default patch.

 

So I'm fiddling around trying to get the default patches uploaded but I can't seem to get MBSIDV2_Editor_v0_5 to transmit anything successfully.

 

The unit has an old version of the software installed (midibox_sid_v2_041 & MIOS 1.9g) so I thought I'd try and get midibox_sid_v2_044 to install.  Try as I might, I couldn't get MIOS Studio to catch an upload request.

 

Round about now (20 minutes or so in to my fiddling) the bank sticks started formatting.  And now we are back to turn on, bank sticks format - sometimes one bank after another, sometimes one repeatedly, sometimes returning back to the default Pinit Lead patch screen for a few seconds before starting all over again. Sometime it says formatting 64k sometime 32k.

 

https://www.youtube.com/embed/ou_HhTcUBUI

 

Things I've tried;

 

Pulling the CS altogether - I can still hear the bank sticks formatting and the LEDs flashing.

 

Pulling the opto - same

 

Pulling the 8 bit registers and the sides - same

 

Leave just one bank stick - same

 

Pulling all the banks - obviously no more formatting the bank sticks now

 

Other things I've noticed;

 

If I play a few notes quickly one after another I end up with no more sound. Power cycle brings it back.

 

Sometime while formatting the bank sticks I get the odd higher tone that the standard beeps.

 

Sometimes the LEDs freakout while format looping - usually they flash in a cross pattern but sometimes I'll end up with a line of four just on.

 

 

 

So what to do now?

 

Replace the Optocoupler?


Replace the bank sticks?

 

Replace the PIC?

 

Has the PIC been bad flashed at some point - I remember having a bit of a nightmare getting it to flash 3 years ago and only succeeded in Linux in the end.

 

I've double and triple checked the components are in their right places - all the solder joints have been reflowed with a good solder station (Metcal sp-200)

 

Is something overheating as their are odd intermittent occurrences.

 

 

Can you help?

 

I'm UK based in Cornwall - if you think you could send me a programmed PIC to swap test please let me know

 

or if you are not a million miles away and have a known good MIDI interface we can try let me know

 

or if you have any other good ideas as to how I can get this Sammich singing nicely - let me know

Edited by Shiftone
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Hi

I think there the power supply may be not efficient. 0,5A is a border/edge, you should maybe try 1A. I have 2 SIDO's which are very similar to sammich's and one with 2 SID's work perfectly on 0,5A 12V power supply but another with only 1 SID just starts to boot and restarts. Even lcd baclight is doing the same. It may be everything: memory's needs some current, capacitors has their ESR, PIC needs some current, leds needs current. You dont know how many need each element and you cant calculate it precissely. Even that you need something to loss on diode rectifiers and 7805 + 7809 regulators. This everething may produce your problems so try little stronger power supply. Another thing is that SID not properly started can be damaged. Prey to God because you have symptoms that both of your Sids are broken. They may be just symptoms but definitely you have to check them.

Cheers

Edited by C_04
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I've got various other 12v PSU to hand - I've tried a 2 amp switchmode and big 12.5a switching that I bought for a 6 channel Tripath amp project.

More weirdness - the bank sticks have stopped looping round. But the CS goes straight to the ENV Dep Del At1 ALv screen and the LEDs aren't flashing like they used to...?

 

My MIDI interface in MIOS Studio is spitting out f0 00 00 7e 40 01 f7 in the MIDI IN windows when I power cycle.

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Has the PIC been bad flashed at some point - I remember having a bit of a nightmare getting it to flash 3 years ago and only succeeded in Linux in the end.

 

Yes, this could explain the behaviour (and based on that what I see on the video, I can say that this isn't normal)

 

 

Please try it with a proper MIOS and MBSID installation:

 

- power-off the sammichSID

- load the mios_v1_9h/pic18f4685/midi/mios8_v1_9h_pic18f4685.hex file

- press the Start button

- now power-on the core

-> upload should be finished within ca. 10 seconds

 

After MIOS has been installed successfully, the MIDIbox SID application can be uploaded without this special trick.

 

Btw.: is your MIDI interface on the blacklist? -> http://www.midibox.org/dokuwiki/doku.php?id=midi_interface_blacklist

 

Best Regards, Thorsten.

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I could do flash the PIC for you but unfortunately im in Poland. Then we could try to say whats wrong more. Anyway in case your CS is shorted or any other problems may be there my advice is to disconnect entire CS. Keep only LCD connected. Use stronger power supply than this 0,5A and then try upload MIOS to your PIC if you wanna try it by yourself.

Cheers

ntire

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Ok, some progress.

 

I have managed to update to MIOS 1.9h and  midibox_sid_v2_044 using my old Alesis Photon X25 on my Macbook Pro.  I have also successfully uploaded the default patches using the SysEx tool in MIOS Studio. So the bank chips are working and the PIC is doing what it should.  Haven't seen the formatting bank sticks error for a few hours now.

 

I do however have some weird intermittent issues with the CS. LEDs sometime just plain don't work - sometimes the innermost 3 LEDs on each side are on from power on, sometimes they work fine.

 

The LCD usually flicks over to a page that says -  ENV Dep Del At1 ALv

 

If i tap the MENU button repeatedly I can make it go back to the patch selection screen momentarily (usually long enough to scroll through a couple of patches)

 

Patches load and the Sammich is making the right noises - just the CS issue to resolve I think.

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As i said previously - disconnect entire CS. Use only LCD and check whats happening. If no problems with stucking into ENV page then definitely you have something wrong with CS. Another thing is to check CS connector there may be weak connection. Next shorts!! Check every switch. Im not sayin that any of them is broken but it helps you localise which is which. ENV page if i remember - second is responsible or somehow.  Next you may disassemble ICs from CS and mount only shift registers responsible for buttons, try different order. Blinking leds are last thing what you need now;)

Cheers

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LCD is fine if removed from the CS - so yeah - CS issue.

 

If I pull both CS ICs - problem disappears - but obviously CS is now not working.

 

If I put the left hand IC back in the error returns - so where ever the issue is - it is connected to that first logic chip.

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I'm going to say Sammich lives!

 

 

Turns out to have been a few issues compounding into one wonky Sammich.

 

Bank sticks issue - I'm fairly sure this was PSU related.  I've moved to a 2A 12v switching supply that I used for a Tripath amp previously.  I'll look for a better quality linear (or build my own).

 

CS and LED issues - putting this down to poor solder work. When I built this box 3 years ago, it was about my 3rd ever proper project and I was using lead free process with a 300 degree C tip and cheapo Chinese fake flux. I ended up using a heat gun to pull the resistor network below the first CS register, cleaned up the pads and resoldered. After this work the bottom left switch was acting up causing all kinds of CS weirdness (gently tapping it made the issue occur).

 

Heat gun removed and resoldered the switch.

 

Reflowed most of the board with the heat gun and my soldering iron (mine is now a toasted Sammich ;) )

 

After that - Sammich played nice for the rest of the evening - both in Sidplayer mode and synthesis.

 

Thanks for all your help and moral support. I can now haz Sammich.

Edited by Shiftone
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