3v3, 12v Smps: "Design ok!" "Pcb ok!" Why not stable? Please Help
For Lm2676 IC:

I changed my power supply and multimeter,assembly new pcbs today  with used all components again. The pcbs is ok, no voltage going down or no current limits. So i changed my power supply and multimeter back and test again, nothing change there is no problem. I cant say anyhing exactly for problem source. I think the IC pad maybe didnt soldered or pcb quality is not enough for smps.

All smps work perfect. So we have 3v3-3A, 5v-3A and 12v-3A now. I cant test in high ampere mode more than 10 seconds. My resistors is not enough for that watt. When i test for a longer time, i write here the results.

I cant work on LM2696 IC yet.

Thank you for your replies.

for 5V smps:

IC: 1x LM2676-5V, Inductor: 1x P0841, Output Cap: 3x 100uF (10V 1.1A(Irms)), Input Cap: 3x 22uF (50V 0.6A(Irms)), Boost Cap: 1x 10nF, Schottky: 1x 40V (3A), FeedBack Res: none but connect fb pin to VOUT