Hi! I finally started to build my Shruthi today, and I just finished assembling the power supply on the SMR-4 board.
I came to the stage where I have to test the board, but voltages turn out to be wrong:
ground is zero everywhere… so far so good
but positive is 6,8 instead of 5 and negative is -6,8 instead of 5
I double (triple) checked all the polarities and if the components where the right ones… so far I can’t find an error…
Now… either my tester is wrong (could be, it’s a bit of a piece of crap) or I have done something wrong during assembly which I don’t know of… the strange thing is that I get pretty strange values also when testing the output of the power supply. shows 12V while I set it to 9…
Any suggestions?
I’ll try to find another tester… just not so easy since it’s sunday… but maybe there is something else I could check.
ok… I’m a noob
the batteries were running out on my tester…
problem solved so far…
hey rumpelfilter, im just as stupid as you 
new batteries in Mr.Voltcraft magically corrects all weird Voltage readings on the Shruthis - must be some kind of morphogenetic field …
Honestly: what about compiling a “The ShruthiVersum™ Guide to SynthDIY for Noobs” FAQ with all those hints and tips and tricks?
fcd, yeah why not? it could also say: dude when everythings working, but no sound at all, why not start with inserting …some of the transistors? that was me yesterday, glad & stupid at the same time
My Physics teacher at School: “It works better with electricity.”
My personal all FilterBoard Favourite is: put that damn white stripe on the ELKOs exactly where it is on the pic. Dont think just compare. Twice!
Maybe wo could also start a “Too dumb to build a Shruthi” Yahoo Group or something…
great idea!
Here’s what my highlights of the day were:
- soldered one transistor the wrong way around, and i was even convinced I hat put it the other way, then, since desoldering would probably burned the transistor out, I cut the legs above the pcb, thus rendering them too short to get back into the pcb and one leg totally broke off. So I had to attach 3 solid core wires to it to make some “new” legs. It works, but I was close to rendering the component unusable…
- added an IC the wrong way… here also I was totally sure of doing it the right way…
- When I was done soldering the machine strips that connect the control board to the filter I thought I had done it wrong thant the long leads were too long… so I removed it… just to notice that in fact it was right…lot of work for nothing.
despite it all the Shruthi works! can’t believe it!
congrats!
yep somehow i know this procedure… wrong… what… was actually right… doh (usually the last part you have)
Must have been a hell of a Party last night…
But yes, i managed to reverse a transistor, too. Ready for some desoldering tips?
- Do not desolder at all. First think, then solder else socket™
- Use a low power soldering Iron (15W or less) to prevent burning the board.
- For 2 or 3 Pin Parts (Resistors, LEDs, Caps or Transistors etc…) you have a chance by heating one Leg and bending the part to the other side. Repeat with the opposite pin to prevent overheating.
- For parts with more pins use a socket
If you didnt: get a new part, cut the pins and desolder the wires one at a time. Use a socket next time. - If there is Solder left in the hole (it shurely will) you can use fancy things like vaccum sucking tralala etc. Or go the LowTech way, get a needle from a Syringe
, heat the hole and push the neddle thru. The solder wont stick on the stainless steel needle.
- By all Means be gentle to your board, as gentle as you are to your grilfriend. This is not an Aircraft Carrier!
Trust me, i know what i’m talking about:
