I purchased the Shruthi-1 kit, and i assembled the digital board without incidents. When I was testing the voltages of the filter board, I realized that the 7905 and the 7805 were swapped. I putted them correctly, and all worked until I have the brilliant idea of putting straight the VR. After that, only worked the negative voltage (I get -4’97v), while the positive voltage isn’t working (around 0’02v). I measured the voltage at the VR and it was correct. I tried to change C20 and C30 (I thoght they maybe were burned or something), but the problem reamins.
Thanks for the support of this forum. You’re all great.
Use the tester on continuity checking mode to check that the voltage regulator’s leads are actually making a good connection with the circuit board.
If this doesn’t appear to be the problem, then it’s probable that the 7805 has been damaged.
Thanks I’ll try that.
Yes, is that, I ripped off the pcb pad while i was desoldering.
Can you cobble something using wire, or even the remains of a cut resistor leg?
I hard-wired the +5v leg of the 7805 to the +5v port of the J4. It works! By the way, I get no sound (MIDI is working). I broke two legs of the LM13700 and I made a shoddy job soldering cuts of reistors legs for replacing them. Can be that the cause of no sound? Any idea where I can get the LM13700?
> Can be that the cause of no sound
Oh yes, certainly. The best is to trace the signal path to get an idea of which building block (mixer, filter, vca…) is not working. Check the end of the SMR4 build instructions.
> Any idea where I can get the LM13700?
Check the published BOM, there are references for Mouser, Digikey, Farnell, Reichelt…
I’ll try that.Thanks for all your help.
Will one of these work?:
Yes, but there are probably local distributors that will ship faster and for as much as money as asian chip sellers (and you have the guarantee that the parts are new and genuine).