Shruthi Ground Connection Not working

Hey everyone, Sorry to bug everyone with such a simple problem but I cant figure out where to start.

I just finished putting together my Shruthi and SMR4-mkII filter board. I can’t seem to get the ground connection to work. I am using a DC 200ma 9v power supply Center pin positive.

To get it to power on Ive soldered a wire to the grnd connection on the digital control board and have alligator clipped it to the ground of my multimeter.

Ive run all of the checks on the filter board and all of the voltages were correct, I dont know where to begin Im guessing it was bad soldering any advice on how I dont have to use this fix to make it work? any help would be great!

here are some photos

I guess your power supply has too little power. Try a power supply with at least 300 mA.
And I would suggest to resolder the connection between the two boards (especially the GND on the control board).

I doubt its the PSU, he doesnt even have the LCD on… Shruthis draw about 150 mA so 200 should be fine.

dylthepill: Do you have a volt meter? If you do, with the two board mated, check continuity between either of the top two pins of the DC socket and the GND pin of the digital board. If those are not connected, then the issue lays with the SIL header or Pins

Thanks for the quick responses cj55 and altitude

Ill have to try maybe a 300mA powersupply (hopefully this is all I need to do)

altitude: I checked the continuity like you said and it seems I do have continuity and their isn’t a problem with the connection? any ideas what to try next?

I’m not getting really clear what your problem is. Does the shruthi power up with the extra wire soldered to ground or not?
You can’t use the ground on your multimeter to ground the digital board. It needs to have ground with it’s own power supply which is on the filter board.
Did you put the 2 boards on top of each other? If you do so be sure that the regulators don’t touch the bottom of the digital board. I usually insert a piece of foam in between.

shiftr: yeap the shruthi does power up when I have a extra wire soldered to the ground connection on the digital control board and I have the two boards together I have been using the spacers in the case to keep the boards from touching.

all of the buttons seems to be functioning fine and the LED’s are also lighting up, the shruthi loses power if I desolder the wire. Im going to test out the audio in a few minutes

Must be the soldering on the headers between the boards then…

hmm strange Ive tried to resolder them but no luck, maybe I should go and buy a new set of headers and pins? The wire fix isnt a big deal though the audio is also working fine!

I cant get the LCD screen to work either, its the same kind of fix if I solder one wire to the bottom pin on the amp and one wire to the middle pin of the amp on the top of the control board the LCD seems to work just fine

Would you think this is because of the headers also?

What do mean by amp?
Did you try measuring if you get continuity to ground on the header?

not sure why I though It was a amp, what I meant was the The trimmer (R21) and Yeah ive tried measuring the continuity and everything seems to check out just fine!