Sunking IC3 voltage issue

[Doc Plus]

Hi,

IC1 = TL072              IC2 = TL072                 IC3 = MAX1044CPA
4.6                          4.6                             9.3   
4.6                          4.6                               0 (should be 4.6)
1.2 (should be 3.4)     4.6                               0
0                              0 (should be -8.5V)        0 (should be -4.5V)     
4.5                           4.6                              0 (should be -8.5V)
4.6                           4.6                             4.4
4.6                           4.6                             4.2 (a bit low)   
9.3                           8.2  (should be -16)       9.3       


Moreover IC3 is very very hot. All the electrolytic caps are 25 or 50V. I replaced them all but it changed nothing. I also replaced the zener.
I tried 3 different IC3 but all were MAX1044CPA. I read I should use MAX1044SCPA.
Do you know a place where to buy one with low shipping ?
What's the difference between CPA and SPCA ? Could this explain why my IC3 is so hot ? I can't let my finger on it !

[madbean]

Yes you should use the SCPA, but there is something else going on there with your build. If the IC gets hot, there are only a couple of causes: it's in backwards, or there is a bad solder or solder bridge somewhere. Given that you are reading 0v on pins2 and 5, I would look for a place where those are grounding out.

One last thing: it could be a faulty electrolytic cap...C18, C19 and/or C20.

[Doc Plus]

I received two 7660, so no excuse to try again ...

The problem was that pin 2 & 4 of IC3, C21 + & - and C20 - were grounded.
I desoldered IC3 support, C21 and C22, and the problem was still there ... which means the problem came from the PCB.

So I resoldered an IC support but I removed pin 2 and 4. I soldered C21 directly to MAX1044, and C20 - directly to C21 +.

Now my sunking is working.