Yeah. So I put the Anushri together, and powered it on. All the LEDs were working, and the buttons changed the page causing different LEDs to go on or off, but no sound would come out of it. I noticed that there was a lot of heat coming from where the 7805 and 7905 were, turned the unit off and saw upon checking the instructions that I had them in backwards. Not swapped with each other, but that each one was in backwards compared to how it was in the pictures.
Now to make things worse, I then de-soldered them both intending to flip them around and in the process, I pulled up the pad and the copper core from the board on the 7905 terminal marked “0”.
So now that I’ve gotten myself in this deep I decided to come and ask for help. How much damage have I likely done by having the 7805 and 7905 in backwards? The unit was only on for a short period of time, but the chips were in it.
Would it be acceptable to solder a lead from the output of the 7905 to the back of the board solder point for the negative terminal of C49 in an attempt to bypass the damaged part of the board? I am unsure how to extract the solder pad which is still stuck on the other (ground I guess) terminal of the 7905 and I’m afraid if I try to pull it off I’ll end up breaking the thing. Thanks for any help or advice you can provide. I am pretty amateur at this, just hope I will be able to salvage the project.
Here is a picture of the board: http://imgur.com/ahstecI
it doesnt look that bad, solder the chip in and check continuity between the pins and the next part it connects to. It looks like you pulled the pad on the side where there were no traces anyway so you may be ok. Solder wick as much extra solder as you can so you dont tear up the through holes any more. A little LESS heat + solder wick takes longer but it reduces the chances of delaminating the foil from the fiberglass so this is something you want to be as gentle as possible with
Yeah I was afraid of damaging the chip with heat and instead I damaged the board. The traces are on that side though. The trace is under the white part.
so you can’t get it make contact?
check the schematics for the part(s) it needs to be connected with. put a new one inside, solder the good legs and cut them. then use a wire (maybe insulated) and put that between the leg and the next component leg. wrap it tightly around the legs and solder it there. that should work.
edit: that would be on the top side then i guess
7805 and 7905 are very solid. But if you afraid to put the de-soldered ones into the PCB again, a new one costs 1/3 EUR a piece.
Rosch, that is what I ended up doing. No big deal.
If it makes you feel any better, as I was assembling my Anushri, I managed to reverse my 7805. It took some work to desolder, but I eventually got it, and corrected it before I applied power.
Also, I had been reading too much about the Ambika, and had it stuck in my mind that the Anushri needed an AC power source, and plugged in 9V AC to it. I couldn’t figure out why my power readings were all off.
After realizing my mistake, I Googled how damaging my blunder might have been to the components, and it didn’t sound good. At all.
I know Olivier has designed these synths with extra protection and safeguards knowing that people would make mistakes, and I don’t know if I have that to thank him for, or whether I just got lucky.
Anyways, good luck. You’ll get it. The Anushri has really grown on me. It’s so much more interesting than any average ho-hum analogue monosynth.
Yeah I just soldered a wire to the other side of the board and it seems to be working good so far! thanks for the advice