powered sub wont come out of standby

[moss99]

Re: powered sub wont come out of standby

I have noticed a slight buzzing / frying sound in the area shown in this pic , i cant really pinpoint it though . is that normal ?

[moss99]

Re: powered sub wont come out of standby

I took out the relay and it tested a bit differently across the pins with ohm meter so i swapped it with the new one still the same , the old relay i found clicks when i put 12 volts across pins arrowed in red on this pic.

[moss99]

Re: powered sub wont come out of standby

the lower pin on the relay in the photo is earth , and there is 12 v on one side of Q17 , so should 12 v be going across Q17

[budm]

Re: powered sub wont come out of standby

Right now I believe the relay is in the OFF state and not being allowed to turn on due to DC offset at the output of the amplifier.

[moss99]

Re: powered sub wont come out of standby

Bit of an update , i was looking at the pins of the mosfets i removed for testing and noticed they were not all that clean , (flux residue and gunk) , so i gave them a good clean up and now i have a steady green led . I can hear the relay click on power on .
But no sound from the speaker when i connect it all up ,.

[srhofmann]

Re: powered sub wont come out of standby

Just to clarify things a couple of questions?

1. Does it work when the power switch is in the on position?
2. Does it work if it's in auto using the 12Volt trigger? Not as critical to know as #1
3. You said you cleaned up the MOSFETs. Did you resolder them again or just surface clean them? If you didn't resolder them it's almost like you have a colder solder joint and the physical motion of cleaning and moving the board changed things, not necessarily the MOSFETs.

[moss99]

Re: powered sub wont come out of standby

Hi , yes the power switch to on , led is green , switch to auto , led turns red , i have not tried it with the 12 volt trigger , ( i dont have a suitable lead handy ),
I did touch up a couple of the solder joints aswell as a good clean up .

[srhofmann]

Re: powered sub wont come out of standby

Hi , yes the power switch to on , led is green , switch to auto , led turns red , i have not tried it with the 12 volt trigger , ( i dont have a suitable lead handy ),
I did touch up a couple of the solder joints aswell as a good clean up .

Don't worry about the 12 volt trigger. Couple more questions.

1. With the power switch on does it work with an audio input source?
2. If it doesn't work can you let us know what the voltages are at J5, J6 and J7? They should be measured with respect to the center pin of either J5 or J6.

#2 is a quick check to see if power is being supplied to the preamp and amp.

3. Could you test SW1. It got a temperature rating on the schematic so it's probably the thermal overload protection. It should normally be closed. If it measures open you could try a quick test by jumpering it and seeing what happens.

Part numbers were taken from the 2nd page of the AW-12_power_v2 schematic.

Just as an aside I would probably do my testing with the amp in the on position instead of automatic just to make things a little easier.

[moss99]

Re: powered sub wont come out of standby

1, not working with audio source , i have an svs cylinder sub set up and working on my main system , playing a set up test tone so i know there is definitely output form the source ,, no sound .
2 , voltages (see pic) all voltage tests were with ground probe on J5 center pin J7 volts look a bit strange ?? .



SW1 is closed .

[srhofmann]

Re: powered sub wont come out of standby

All the voltages are in spec according to schematic. My gut feeling is that the power supply is O.K.

Still working on my morning coffee, please be patient with me. Some more clarification.
1. This thing has separate preamp and amp boards? Could you take front and back pics?
2. Have you looked for good voltage levels in the preamp and amp sections? If there's any ICs on them pull a datasheet for the device and look for power. They may be taking the +8 or +15 and turning into 3.3/5/12 on the preamp or amp.

I'm having a hard time with the voltages on the relay that budm said was for speaker protection. If you had 8.8 volts at the speaker+ terminal and the relay is closed I would have thought you should be seeing 8.8 volts on another terminal. The 6.2 volts is on the plus side of coil?

[srhofmann]

Re: powered sub wont come out of standby

All the voltages are in spec according to schematic. My gut feeling is that the power supply is O.K.

Still working on my morning coffee, please be patient with me. Some more clarification.
1. This thing has separate preamp and amp boards? Could you take front and back pics?
2. Have you looked for good voltage levels in the preamp and amp sections? If there's any ICs on them pull a datasheet for the device and look for power. They may be taking the +8 or +15 and turning into 3.3/5/12 on the preamp or amp.

I'm having a hard time with the voltages on the relay that budm said was for speaker protection. If you had 8.8 volts at the speaker+ terminal and the relay is closed I would have thought you should be seeing 8.8 volts on another terminal. The 6.2 volts is on the plus side of coil?

[moss99]

Re: powered sub wont come out of standby

im not sure which the preamp is , if you look at my first post , 1st pic i thought is the power output board , 2nd photo is power input , is preamp the board in the last photo ? thats the board with the input connectors an switches .

I think i have another problem , one of the pads on the relay pins seemed to come off , see photo


I cant see any trace going to the pad though ..??

[budm]

Re: powered sub wont come out of standby

Did you remove the relay?
It looks like the relay pins are not well soldered, some of them has ring around the pin. You may want to look at all the boards to see if they also have that some kind of soldering works or not.
If you look the top side of the board, does it has any copper trace connecting to that pin?
I believe that N.C. pin of that relay is not being used.

[srhofmann]

Re: powered sub wont come out of standby

Yup, board with the input connectors is probably the input board. Just take a look at the voltages going to some of the different ICs just to make sure that they are being powered.

Have you checked to make sure the speaker itself is still good and the voice coil hasn't opened?

If you wanted to try something quick and dirty you could just try jumpering across the relay. From the input pin of the relay, that's to the left of R42/D15, to the speaker + terminal.

I'm still having a hard time wrapping my head around the different voltages between the input and output pins of the relay that were in the picture in post #36. According to the datasheet for the relay it's a straight shot through it. I guess a cold solder joint could be causing the difference or the contacts in the relay aren't making good connection. When the relay is closed it should have around 100 milliohms between the input and output.

Budm - the upper right pin is the normally open pin and when the relay is energized it closes.

[budm]

Re: powered sub wont come out of standby

I made my correction on my post 53, that is N.C. pin.

[moss99]

Re: powered sub wont come out of standby

Hi , yes i replaced the relay with a new one , the top of the board does have a pad for each pin but i dont see how they could have been soldered at the top , under the relay . Or how i could solder the pins topside of the board .
Ive tested the driver with a tone generator i have , it tests ok ,
I now have relay click but no green light ,

but jumping across the relay. From the input pin of the relay,, to the speaker + terminal. gives a green led ,

[moss99]

Re: powered sub wont come out of standby

preamp top bottom pics .

[tibimakai]

Re: powered sub wont come out of standby

Can't be bad capacitor?
My Onkyo sub, runs very hot in an enclosed box.

[srhofmann]

Re: powered sub wont come out of standby

If the relay clicks but you only get the green light when you jumper across the relay it means you don't have good solder joints at the input and output terminals. Let's get back to having a green light when you power on the amp and then we'll take it from there. Try redoing the input and output pins of the relay.

You should end up with a nice shiny joint without cracks/crevices between the pin of the relay and the solder. You should end up with a nice smooth joint, it's ok if you want to add a little more solder. You should be able to add a little more solder by touching it to the pin and pad next to the soldering iron tip, without really touching the tip itself, it should flow. An example of what it should look like is where the + speaker cable is soldered and the pads near c49,r84,r86, smooth and shiny. Sorry if you already know what to do, figured more info is better.

[moss99]

Re: powered sub wont come out of standby

Here is a photo of under the relay ( top side of board) should any of these pads be connected ?