My Anushri is not making sound. Help!

I recently assembled an Anushri kit. The kit is completely put together but I cant get it to work properly. I get some noise out of it (not the good kind), but there seems to be little or no response when pushing the buttons/knobs/switches etc. When I check the power distribution with a volt meter, I get hardly any readings from IC21 7905 (the second square-shaped part in the power section). Do I simply need to replace this piece before I continue my trouble shooting? The lights turn on when the power is switched on and there is noise coming out of the machine. Do I need a new set of ICUs?

Any advice you all could offer would be most appreciated! This is certainly the most ambitious electronics project I have ever tried, and though it is frustrating right now, Im learning a lot. Help! This thing looks so cool, I just want to get mine to work.

Thanks,

K

Hi,
some data of your power supply unit would be helpful. In some cases 7,5 V don’t work properly.

Ah. Im using an “enercell” 9v 300mA AC adapter from radio shack with a center positive tip attachment.

Is it really AC? For Anushri you need DC. AC (in)/DC(out) to be clear. Not AC/AC.

To me, that looks like an AC adapter. That is, it takes AC and turns it into 9V DC. Should be fine. I’d go over the solder points in the power supply area. Also check out the headers that connect the two boards together. Good luck - I still haven’t gotten my anushri working 100%. Need to get a multimeter!

hmm. does this look right or wrong…?

It seems to be right.
Can you measure the input voltage and output voltage of the 7905?
Is the 7905 getting hot?

Don’t trust the current output. They often don’t deliver what they say they do. So if it wants 300mA then get a 500mA supply or larger.

The 7805 is getting really hot, the 7905 not so much. The output voltage from the 7905 does not look correct to me. It’s reading 0.26 or thereabouts, which makes me think the piece is not working properly.

The question is, is the 7905 getting the right input voltage. If not, then the problem might be the LT1054.

Is there any way to test the LT1054 without an oscilloscope? Also, how would I know if the 7905 is getting the correct input voltage?

You can measure the voltage between GND and pin 5 of the LT1054. This is the input voltage of the 7905.

One of the pins of the 7905 should be above -7V, the other very close to -5V, and the other grounded. If this is not the case, then there’s either a problem with the 7905 or with the LT1054 which generates the negative voltage for the 7905.

When measuring the voltage between GND and the LT1054, the first point (number 2 on the “power distribution” picture in the troubshooting section of the diy page) I get the proper reading, but when i measure the second point (number 3) I get barely anything. Should I order a new LT 1054 chip? or a whole new set of ICUs?

Check first that none of the capacitors around the LT1054 are correctly soldered (and no reverse polarity!).

All capacitors are properly installed.

Alright, all of my capacitors are installed correctly, I replaced the LT1054 and also the 7905. Same deal. Wrong voltage readings, not making sound, etc. Any more advice…? I want to get this thing to work but Im losing steam.

What are the voltages on each of the 7905 pins?