Son of Kong Clone on the DL again

[Peacheater81]

Hi,

This is the second one I've built.  Everything works, but the 20db boost 4PDT switch.  I haven't tried the xlr either.  I reflowed solder over the 4pdt contacts.

The V1 channel sounds good, but when I switch to V2 with the switch up in the 20db boost position, its really quiet.  The volume still works and all the other controls, just really really quiet.  When I flip the 4pdt switch down, it gets loud like it should.  But it should be quite a bit louder on the 20db boost position (up). 

UPDATE:

I thought I fixed it and then it just stopped working on that switch position and the green side of the LED flickered and is not coming back on.  The Green color of the dual (channel) led is for V1, V2 is red and that is the channel where the switch cuts in and out on the 20db boost position.....I celebrated too early!  I thought maybe a loose bit of metal etc so I blew it out with compressed air, but no good.

Any thoughts are much appreciated. 

[Peacheater81]

I fixed it!!!!

I just used a toothbrush and 70% Isopropyl.  Ahhh...too early for a beer?

[antonis]

Ahhh...too early for a beer?

Are you kidding..??
(it's never too early for a beer..!!)

[Govmnt_Lacky]

I fixed it!!!!

I just used a toothbrush and 70% Isopropyl.  Ahhh...too early for a beer?

THAT feeling.... Right at THIS moment in time...

THAT is what keeps people building. That moment when you fire up a build and it works flawlessly. THAT is what will keep bringing you back. Good Luck and Welcome to the obsession 

[ThermionicScott]

Ahhh...too early for a beer?

Are you kidding..??
(it's never too early for a beer..!!)

You can't drink all day if you don't start in the morning!   

[Peacheater81]

I celebrated too early!

Now the green side of the dual color LED flickered and died and I'm still having the same problem with the 20db boost in V2 cutting in and out.  I thought it was a loose piece of metal grounding out, but I haven't found it yet. 

Any thoughts??

[Peacheater81]

I replaced the bi-color LED and its working.  The 4PDT toggle also seems to be working because it works on V1 (boosts volume), which is the first channel.  However, on V2 (second channel), the 4pdt, is extremely quiet in the 20db boost setting.

[digi2t]

Perhaps too much heat on the switch lugs? Damage to the internal contacts? I bring this up because of the intermittent nature.

[Peacheater81]

Perhaps too much heat on the switch lugs? Damage to the internal contacts? I bring this up because of the intermittent nature.

Yeah, it's possible. I try to be as fast as possible, but I'm not perfect for sure.

Is there am easy way to tell the switch is bad (dmm etc)?

[digi2t]

Is there am easy way to tell the switch is bad (dmm etc)?

Continuity test between poles.

[Peacheater81]

Ah, great tip.

I just checked all the switches and they all work. 

[digi2t]

If it worked after washing with alcohol, then perhaps the alcohol was providing temporary continuity? In that case, I would consider reflowing the solder joints. Maybe all of them. Looking at the big picture, some of the joints look shifty.

[Peacheater81]

I just rechecked the continuity on the 4pdt switch and I have contact between the bottom and middle rows with the switch down, which may mean that I have a connection when I shouldn't.  I'm going to try and suck the solder out and see.


UPdate: 

From the bottom, I don't see gobs of solder sticking out.  When the switch is toggled down, there is more than the contacts listed above.  I'm taking a break for this one.  I don't think I will be able to remove the 4pdt switch as I'm not able to suck all the solder out.

[Govmnt_Lacky]

I just rechecked the continuity on the 4pdt switch and I have contact between the bottom and middle rows with the switch down, which may mean that I have a connection when I shouldn't.  I'm going to try and suck the solder out and see.

Maybe this will help....

1   4   7   10
--  --  --  --
2   5   8   11
--  --  --  --
3   6   9   12
--  --  --  --

Looking at the switch like this, when you have it in 1 of the positions, you should read continuity between 1&2, 4&5, 7&8, 10&11

Push the footswitch and then you should have continuity between 2&3, 5&6, 8&9, 11&12

[Peacheater81]

I just rechecked the continuity on the 4pdt switch and I have contact between the bottom and middle rows with the switch down, which may mean that I have a connection when I shouldn't.  I'm going to try and suck the solder out and see.

Maybe this will help....

1   4   7   10
--  --  --  --
2   5   8   11
--  --  --  --
3   6   9   12
--  --  --  --

Looking at the switch like this, when you have it in 1 of the positions, you should read continuity between 1&2, 4&5, 7&8, 10&11

Push the footswitch and then you should have continuity between 2&3, 5&6, 8&9, 11&12

Thank you, yes this helps:

Switch toggle up:  continuity between 2&3,7; 5&6,8,9; 11&12

Switch toggle down:  continuity between 1&2; 5&4,3,6,7,8,9; 10&11

[digi2t]

With the toggle up, check for shorts between the upper (opposite) lugs, and vice versa. Just to make sure you don't have a solder bridge underneath, between the switch body and the PCB.

On a related note, one should be careful when soldering in these switches. There's generally quite a bit of space to fill around the lug, so it's easy to get overzealous with the solder and flood the space. So much so that excess solder can actually overflow onto a neighbouring pin(s). I speak from experience to this regard, so take it for what it's worth. Since then, I've learned to only use enough solder to not have any gap around the lug. This generally leads to a depression around the lug, rather than the nice volcano shape that we like to see, but at least I know that I haven't shorted anything out.

The reason why I bring this up is because looking at the close up pic from the original post, I see some lugs that are completely covered in solder, and some that the top of the lug peeks through. The ones that are completely covered (bubbled over) worry me. Looks like way too much solder was used.

Also, because of all that space that needs filling, leaving the soldering iron in there too long is another hazard. This tends to soften the plastic around the lug to the point that the lug moves, throwing the internal contact out of alignment. Then it cools, and guess what... dead contact.

[Govmnt_Lacky]

Switch toggle down:  continuity between 1&2; 5&4,3,6,7,8,9; 10&11

So are you saying that with the switch toggle down, you get continuity between lug 5 and lugs 3, 7, 8, and 9? 

Problem there.

[Peacheater81]

Yeah, I'm f'ed I think.  Any tips for removing a 4pdt toggle switch?  Dremel?!