Problems with Crack

[watonwak]

Hi,

I just built a Crack as my first electronics project.

It was all going pretty well, passed as resistance and voltage checks, i plugged it in and all was well. That was yesterday.

Today i noticed a slight hum in the right channel that went away temporally if i tapped the top metal plate, but the hum would return after a few mins.

After reading through the forums I decided to re-flow some of the joints, mainly around the volume pot. they all look good now (to me anyway) and i checked the resistances again and all good.

Then I tried to check voltages. I got fluctuating low values on 1 and 2, and when i checked 3 there was a spark and now I can see some black marks on the right side 10W 3K resistor and am reading 0V on terminals 1-10

Any advice would be great.

Euan

 

[Paul Birkeland]

You may have just blown a fuse, have you checked that?

I would reflow all of your joints, not just the ones on the volume pot.  I can see a few that look like they could use some more heat. 

 

[watonwak]

I haven't checked the fuse yet. I'll have a look and reflow the joints when I get home and report back!

 

[watonwak]

So I have checked the fuse and that is not the problem. Any idea why I am not getting any voltage readings now?

I forgot to mention, the 2 LED's and the tubes still light up.

I don't have time tonight to reflow all the joints so I will do that tomorrow evening.

 

[Paul Birkeland]

If the LEDs light up, then your DC voltages are not zero.  You may have accidentally set your meter to AC volts for your readings. 

 

[watonwak]

Ah, I was being stupid and my meter was on AC!

All the voltages are now fine!

Are there any joints in the pictures that look okay and what I should be aiming for or any that particularly need reflowing?

Many thanks,

Euan

 

[Paul Birkeland]

I would just reheat them all and add a tiny bit more solder. 

 

[watonwak]

Okay, thanks. I will get on it tomorrow.

Cheers,

Euan