Tim Escobedo's PWM question

[gigimarga]

Hello,

I've built a PWM using the layout from http://www.aronnelson.com/gallery/main.php/v/Choklitloves-album/album16/pwmlayout.gif.html ant it doesn't work.
I used a LM386N-1 instead of the JRC386D (which i can't find anyway here).
Since the schematic is very simple, this could be the problem?

Thx a lot all!

[slacker]

Any 386 will work fine in that so that isn't the problem. Have you put the CD40106 in the correct way round? It's upside down compared to the 386 so pin 1 is bottom right.

[gigimarga]

Thx a lot slacker!
I verified the PCB and I'd put the 40106 in the right position.
I used an HEF40106BP - could this to be a problem?

[oskar]

No. Audioprobe and voltages!

[tiges_ tendres]

Hello.

I have noticed that you seem to have a lot of problems with all of your builds.  And that's not a slight on you in the least.  But it might be worth checking your supplies.  I think you had problems with a red Llama (right?) and you are also having problems with this build.  Are you making sure to de-static yourself?  If I remember correctly, those CD4xxxxx Chips are very static sensitive. 
Also, one of the problems I had is that I bought resistors, labelled the bag I put them in, then couldnt figure out why none of my builds either sounded right, or straight up didnt work.  Turns out that they were not the resistor value I thought they were, and as such they tripped me up on all of my builds until I went back manually with multi-meter.

Just a few thoughts.

[bluesdevil]

Yeah, I would start checking the resistors with a meter before soldering them in, just in case. Especially if you're getting them from Futurlec. In the past they've sent me 4.7K instead of 47k and 470R instead of 470k...man, the headaches that caused until I realized what happened!!!!!

[Radamus]

If you soldered directly to the board (no sockets) that can also be the problem. I had one of these working beautifully on breadboard, but soldered the same components and completely killed one or the other. Have been too lazy to buy more 386 to actually rebuild, so I can't be more help, but I know some of the chips can be heat sensitive.

[gigimarga]

Thx a lot all for your ideas!
The problem was very hard to detect: pins 1 and 3 of the socket of the 40106 was inner broken!!!
I've replaced the socket and all it's OK now!

I have noticed that you seem to have a lot of problems with all of your builds.  And that's not a slight on you in the least.  But it might be worth checking your supplies. 

You're right...here, in Romania, it's hard to find good components at good prices...

[gigimarga]

Yeah, I would start checking the resistors with a meter before soldering them in, just in case. Especially if you're getting them from Futurlec. In the past they've sent me 4.7K instead of 47k and 470R instead of 470k...man, the headaches that caused until I realized what happened!!!!!

I check the values of the components visual each time and, if i have doubts, i recheck using the DMM!