[Taika-Kim]

Hah, editing this like the 5th time today.

Earlier power issue with 12V close to zero on board: fixed.
The PSU for some reason failed to give correct voltage on load, altough at 9V it worked fine. I bought a new one, a regulated switchmode supply, I hope it's ok that it's a switching one? I don't remember now about all the earlier posts about PSUs for the Sammich.

Rotary encoder acting all crazy: partially solved.
I changed the head of the PSU connector to a more tight one, this made the encoder perform much, much better. Originally it was acting mostly randomly, now almost fine, still sometimes jumps a value or few. Strange that before the unit otherwise worked, only sometimes booted when I was moving this around, this prompted me to change the tip of the PSU.

Now it's almost fine otherwise, but I need to troubleshoot my chips. They are dumpstered 6581s, and the filters are weird. First I thought they are broken, but I noticed that the resonance very noticeably changes the sound, only it's that the cutoff value seems to do nothing mostly. There is maybe a VERY slight effect, but I'm not even sure about that...
Here's a pic of the caps I'm using with 6581s:
capsi.jpg:

This post has been edited by Taika-Kim: 10 February 2012 - 19:41

[nILS]

Before you do what you're about to do (which is good) put the following step:

- Carefully remove the ICs (PIC, SIDs and Banksticks) to prevent (further) damage
- Desolder the shunts and use proper jumpers and undo any other mods you might have done to it.

[Taika-Kim]

Yeah, I wanted to use proper jumper caps too, but the ones I got were loose and I was impatient And my solder gun is totally unsuitable for electronics (way too big, I used it for tiffany glasswork...), so it was hard to make a good solder.

So the jumpers are not the same size than what computers use? Because that's what I asked from the shop... Are they some standard size though? I'll go today back to the shop, but I didn't want to lug the device around with me, and I couldn't get an accurate measurement about the width etc of the pins at home...

[nILS]

[x] Patience is a virtue.

Yes, they're a standard size: 2.54 mm / 0.1 inch.

[Gilesjuk]

If jumper caps are loose use a precision screwdriver to tighten the inner metal loops a little or squueze them a bit to tighten their grip.

[Taika-Kim]

I removed the soldered shunts and SIDs... The ground connections are fine, 5V is 4,97, 9V is 9.03 and 12V is 10.81... The output of the transformer is 12.24V.

It says in the manual, 10.5V should be enough for the 6581s.

Anyway, without the shunts the device powers up, and also if J20 is set to 12V the 12V rating stays at 10.81, but as soon as I shut one of JPB jumpers, the 12V drops to about 2.5V, and with both shut 12V is around -0.47V... So something wrong with the power. I am now using normal jumpers.

So, what to check next. The device is before used on 6582s, so I think the previous builder never even probably checked the 12V operation...

This post has been edited by Taika-Kim: 29 January 2012 - 19:02

[nILS]

Got some non-blurry, high-res pics of the top and bottom side of the base-pcb?

[Taika-Kim]

http://imageshack.us.../sammich06.jpg/
http://imageshack.us.../sammich01.jpg/
http://imageshack.us...4/sammich02.jpg
http://imageshack.us.../sammich03.jpg/
http://imageshack.us.../sammich04.jpg/
http://imageshack.us.../sammich05.jpg/

Hmm, I chose "no resize", but I'm not sure if you can download them at the full res from Imageshack? Or maybe it resizes for your screen always?

Well, here's a link to a zip with all the pics.
http://www.filehosti...909/sammich.zip

This post has been edited by Taika-Kim: 29 January 2012 - 21:06

[Taika-Kim]

So anybody have any ideas what to look for next?

[nILS]

nILS, on 26 January 2012 - 19:01, said:

[x] Patience is a virtue.

I'd suggest you just wait a bit and give people some time to look at the pics and see if they find something wrong. Some of us have lives/familes/jobs ;)

[Taika-Kim]

Some issues solved, in the first post I have now updated state of the unit.

This post has been edited by Taika-Kim: 10 February 2012 - 19:41

[ilmenator]

Taika-Kim, on 25 January 2012 - 11:09, said:

Hah, editing this like the 5th time today.

Just a suggestion here: do not edit old posts except for adding a 'solved' to the title, because only then others can find the thread when doing a search and learn from your problem and solution. Open a new thread for a new problem.

[Taika-Kim]

Ah, good point. I tried to include the information about the original problem to the edited versions too, so some information is retained... But I'll keep this in mind.