Shurthi 1 : no sound output [SOLVED]


Now my lcd is ok, I can see that I have a good midi signal, but there is no sound output… What must I check ?
I have already checked the cutoff…

How about concentrating all your faults in one single thread? You are beginning to clutter up the Forum, and please mark solved Problems with a [SOLVED] in the Title which you can edit in the First Post of your Thread.
This way you are helping troubleshooting as we dont have to jump around in your threads.

You are missing the Bridges next to the Audio Jacks, Dude. See Step 13 of the SMR-4 MK11 Instructions.

Ok I thought it wasn’t a good idea for the other users, but for the next troubles i’ll do that !

edit : i have soldered the bridges since this picture, but there is no more sound…

Check the stacking connector if the Pins are long enough.

If so you can trace the Audio Path like shown here

Use the Search function to learn more about how to do it - its been described many times.

Ok when I check the audio path, there is no mor sound on the 3nd point (pole 1)… what should I do ?
I have search, but nothing about this pole…

HAve a look at the attached Schematics and check all Parts in the Pink Circle. Might be bad soldering…

BTW, it looks as if your Sockets arent flat with the PCB, normally the Pin sticks out clearly visible the bottom…

I didn’t found bad solderings, but I am such a noob…

Here are the pics

In this picture it looks like you do not have applied the bridge at the 2-pole/4-pole switch.

I found some bad solderings and marked it with a Yellow Square in the Pic - There are some especially bad lookings, marked in Pink you should cheek - and all similar ones.

It looks like your Soldering Device isnt getting hot enough, more like you smear some highly viskus sludge to the pads rather than letting the solder flow nicely. The solder should be really liquid else you will have tons of bad joints and it should cover the whole pad including the Pin/Wire/Leg. Yours looks like some Solder is gooey sticking on the Pins, barely touching the Pad.

There are no traces of Flux whatsoever on the board which means your Soldering Iron just is not hot enough. You won’t do any proper Solder joint with the technique you are using.

Also you 2/4 Pole Jumper is missing.

It is always falling when I move the Shruthi, how can I do ?

You killed me with the yrellow square >< ok ill check this and I come back

As pointed above, you have tons of bad solder joints that will lead to these dropouts.

Here is a simple to follow step by step guide (and my last contribution to this thread)

  • get a working soldering iron with at least 300° but not more than 350°
  • get leaded solder
  • redo EVERY suspicious looking joint (that means nearly every one)

All else is to be hopeless because the foundation of your work is missing. I wont chase hundreds of bad Joints one by one.

I am curious what type of soldering iron you used. Is that the kind you can buy in home-improvement/building materials/gardening kind of stores? If this is the case you’d better switch to something more suitable to electronics.

And solder with flux in it… not the one used for plumbing.

Also, don’t add the solder to the iron then try to transfer the solder to the pad. All of the flux will burn off and you’ll get solder joints that look a lot like the ones in the picture.

I highly suggest watching some how-to videos on YouTube. I’m on my phone and can’t get the proper links, but do a search for EEVblog #180 and #183. Everything you need to know about soldering is covered in those tutorials.

Here’s the Links: part 1 part 2

pichenettes : yup, i bought it in building materials because mine (from electronic strore) is 30W, but it seems to be better…
I use electronic tin, i think it is good no ? because except the sound (yeah its kind of funny), everything is working…

Thank you a lot, i will redo everything and come back to you !

Just one hint - it is absolutely crucial to own a solder sucker and a good cutter. The sucker is needed for desoldering and sometimes to get rid of annoying solder blobs, which shorten circuits.
And the cutter is needed to cut off pins too long. This combination will bring a better quality to your soldering and make your life a lot easier.

thank you nightworxx, I have both now, and it is preaty much easier to solder ! Now I have sound at all points, except 9 (out point), and it seems to be good soldered… where must I search for cuts now ? I don’t really understand where the problem could be…

edit : i now have sound on point 9 but nothing output…

Are you sure the cable you use is good?

Yes it works perfectly with my MC303 :-/

Edit : Thank you qp, this blog is awesome !

check the soldering of the resistor just above point 8