Help troubleshooting Ambika Voicecards appreciated

I’ve had 2 “mute” SMR voicecards (with leds working) for a while and would like use some free time to finally fix them and unleash the full power of my Ambika. :slight_smile:
The issue is likely to originate from poor soldering but I’m a bit struggling - to say the least - with reading the schematics in order to identify probing points so I’d be really happy if someone could provide me some guidance about that.

Thx in advance,

I’d first check the connectors. Use a continuity tester to verify that they are okay

I just checked every pins between the Mobo and the Voicecards and all seem ok.

Hi , do you have - (minus) 8 Volt in the IC’s?
The LED’s are working ?? Than you have a mistake into the VCA , or you have made s short somewhere . I picture is helpfull.


Well it looks like i’m getting correct voltages (-8/+8V) on LM13700Ns pins 6 and 11.
Not quite sure how to handle the rest of the ICs though.

Here’s for the nasty pictures :
Voicecard 1

Voicecard 2

Pretty nasty, indeed … not surprising they won’t work …

Take the ICs out of their sockets (to keep them alive) and reflow all those nasty blobs - quite a few pins where there is too much solder, and where there is too little.

I admire your courage to show those pictures :slight_smile:

No worries, we’ve all been there, and this can be fixed. Clean and reflow. Also check for shorts. Should take half an hour at most.

Yes, looks like it is a soldering problem. Look at these pictures, how a good solder joint has to look like. You may have to use desoldering wick and a bit flux to fix your solder joints.
(Thank you heniek and tubeohm who posted these pictures in another thread!)

Yeah well, the other voicecards looks pretty much the same but they work nevertheless…

I know how they should look like in theory but now I guess I need to go back and practice a little more…

Than you have luck . resolder all and pay attention that the solder only is on the pads .
99% of mistakes on the Voicecards are bad solder points .