AMB Laboratories DIY Audio Forums

[Balcmeg]

Hi,

Well maybe not in a coma, but close. I have not been using my γ3 for a while due to surgery and 45 days in hospital and after that no real mood to listen to music, more using Tv to distract myself. Anyway, i tried to start it up today and all look good, display light up and the remote work just as it should. Trouble is I dont get any sound out. None at all..

I have the right Supply voltages everywhere, but there are no signal out formt he a24, no signal in to a24 and no signal out from the γ24.
After some testing I am beginning to suspect that while the processor is still working, the control signals are not reaching a24. If I remember right, the USB input is the default input when the amp is switched on and that might be why i cant get a signal out, since I do not use that input.

Its been over a year since i did anything inside the γ3 so before i start digging on my own I wanted to get some advice here, in particular on how to best check if its the control signal that fails. Or more general, what could be the cause of the problem.

-Stefan

[amb]

It sounds like I2C data isn't going through from LCDuino-1 to the backplane and/or the γ24 board. Look for electrical contact problems, including connectors and cold solder joints.

Use the schematic diagram and follow the L_SDA and L_SCL lines from the LCDuino-1, to U11 and U19 on the backplane. Then, from the other (isolated) side of U19, they becomes G_SDA and G_SCL and go to U1, U2 and U3 on the γ24 board.

[Balcmeg]

Thanks, Ti,

Just what I needed. Based on previous experiences I just resoldered all of the pins for the signal on U11, U19 and the 3 chips on the g24. Didnt bother to measure first. It all sounds fine now and work well fromt he remote.

Only issue I have now is that the Potentiometer dont move when I change the volume by te remote, and the volume doesnt change when I turn the volume knob. An issue I can live with but Ill take a quick look in case it just is a faulty connector - I have had a lot of trouble crimping those.

[amb]

Only issue I have now is that the Potentiometer dont move when I change the volume by te remote, and the volume doesnt change when I turn the volume knob. An issue I can live with but Ill take a quick look in case it just is a faulty connector - I have had a lot of trouble crimping those.

First go into Menu setup and make sure "Pot" and "Motor" are both set to On. If that's not the problem then looks like you have a connectivity problem between the pot and the LCDuino-1.

[Balcmeg]

Hi Ti,

I always liked that you reply so fast to questions in the forum, but couldn't you have waited just 2 minutes longer this time? Your reply came in just as I finished turning on the motor and pot in the menu. The old brain still work, but slowly. I obviously forgot that I had turned off the Manual volume for some reason.

Thanks again!

/Stefan

[amb]

[Balcmeg]

Well, still works fine after putting on the lid. Thats usually when electronics fail as I noticed - when the last screw is tightened and its all in place to play / THEN you have to pull everything apart again

Time to start planning for a new PSU for the g3 now, I might have been a bit stingy on the Trafo for the digital section and the Duino section, plus that I would like to replace my Sigma25 with a real sigma 11. Well, no rush I still have sound!

/Stefan

[Balcmeg]

Real nightmare...
Stopped working again a few weeks ago and i been too lazy to fix it. Now I open it, fix something, it works! I put on the lid and squeeze in g3 in the shelf and connect all cables and it wont work. the i take it out, remove the lid, and it works... I suspect the wiring between LCduino and g3 main board but just cant seem to get if fixed. Sigh..

Not asking for help, just venting frustration!

[amb]

Seems like you have an electrical contact problem that's exacerbated by mechanical stress after the case cover is installed.

[Balcmeg]

Before it took 3 weeks until it stopped, this time 2 hours.
If i get it going again, ill run it without lid and see how long it takes...

or maybe just buy a mouse and let him run wild inside the enclosure, might work just as well as long as i feed him.