How pathetic is that? My jelly bean Samsung Convoy uploads pictures, and came with the USB cable for doing it.

I cannt upload directly from my iphone. I can still plug it in and upload from the computer, though it is still annoying that you cant do stuff like that with iphone

 

Okay so what am i supposed to do with the 22 ohm resistors.

 

So you are ready to power up ?

 

So you are ready to power up ?

Yepp i think so. I soldered in all the replacement parts. The only thing i dont have yet are the output transistors. They should be in next monday (hopefully)

 

OK...then, I'll tell u abt the 22R.

It's a trick used to trouble shoot amps. What you have to do is isolate or break all the connections that goes OUT of the filter caps.

Remember the filter cap is used to supply to take out the ripple. The bridge supplies to the filter and the filter supplies the whole amp. Get what I am saying?

You have to completely disconnect the positive and negative voltage rails except the ground. The only thing connected to the filter then will be the bridge.

Now solder the 22R resistors, One to the positive and one to the negative. Next connect the severed connection to the other end of the 22R resistor.

So now u have a 22R resistor in series with the amp supply circuitry. Any current drawn by the amp will flow thru the (22R) positive and negative (22R) resistors.

This way when u power up and if due to a fault the amp draws too much current, either from positive or negative rails the resistor will limit tht current to a safe value, so nothing blows up in ur face.

Did u get a clear picture on what to do now ?
Post back if u have a doubt. After tht I will tell u how to deal with any fault should they arise.

It would be better if you take a picture so I can see how u have done it.

 

OK...then, I'll tell u abt the 22R.

It's a trick used to trouble shoot amps. What you have to do is isolate or break all the connections that goes OUT of the filter caps.

Remember the filter cap is used to supply to take out the ripple. The bridge supplies to the filter and the filter supplies the whole amp. Get what I am saying?

You have to completely disconnect the positive and negative voltage rails except the ground. The only thing connected to the filter then will be the bridge.

Now solder the 22R resistors, One to the positive and one to the negative. Next connect the severed connection to the other end of the 22R resistor.

So now u have a 22R resistor in series with the amp supply circuitry. Any current drawn by the amp will flow thru the (22R) positive and negative (22R) resistors.

This way when u power up and if due to a fault the amp draws too much current, either from positive or negative rails the resistor will limit tht current to a safe value, so nothing blows up in ur face.

Did u get a clear picture on what to do now ?
Post back if u have a doubt. After tht I will tell u how to deal with any fault should they arise.

It would be better if you take a picture so I can see how u have done it.

So basically ur saying to disconnect positive and negative rails, then solder 22 ohm resistor between each rail

 

Yep.....!!

 

Very high voltage came from where ?

The emitter of Q901 should normally be near 0.025 V. The collector of Q706 normally has -33 V on it. Since Q706 was obviously shorted, some of its collector voltage was surely passed to its emitter. Between the emitter of Q706 and the emitter of Q901 is only about 6 ohms, and one of those resistors, R717 obviously conducted a lot of current since it was charred. I would think it would be prudent to replace Q901, even if it doesn't show outward signs of damage. One of the interesting things about DC coupled amplifiers is that the DC bias can get upset by only a single malfunction.

 

Okay all done. I unplugged all the other wires tho. Do i need to plug them back in

 

I unplugged all the other wires tho.

Which wires are you referring to?

 

Which wires are you referring to?

All of the ones connected to the amplifier board. Only the postive and negative and ground supply rails remain connected. All other wires go to the output transistors and speaker terminals

 

huh !..

Why did u do tht ?

 

huh !..

Why did u do tht ?

So it would be easier to take the board out. The wires have plugs on them anyway, so its not like i have to resolder them

 

Nvmd, i just plugged all the wires back in. So what do I needa do now?

 

Get me a clear picture on the main filter cap terminals.
A focused one Mate.

 

Get me a clear picture on the main filter cap terminals.
A focused one Mate.

is this good enough

 

is this good enough

Im sorry, maybe you cant see a clear picture of what ive done. Ive connected the red wire (the positive supply wire which is connected to one of the filter caps) to the resistor on the left (the bright blue things are the resistors, in case you cant see them that well) which is connected to the postive supply input. Then ive connected the purple wire (the negative supply wire which is connected to the other filter cap) to the resistor on the right which is connected to the negative supply input

 

I will be here for a few hours so let's do this.

Now u have given me a picture, I'll show u a step by step.

But first tell me the status of the amps. Are all the components in place ?

Next undo what u just did in post #117 .

Post back!

I am going to have dinner, be back in 15 min.

 

I will be here for a few hours so let's do this.

Now u have given me a picture, I'll show u a step by step.

But first tell me the status of the amps. Are all the components in place ?

Next undo what u just did in post #117 .

Post back!

I am going to have dinner, be back in 15 min.

Yes ive got all the components in place (except for output transistors).

So you want me to unsolder the resistors?

Or u just want me to disconnect the wires from the resistors

 

Connect the wires and remove the 22R's.

Wires need to be as it is before.

But to do this u need to solder the output stage mate.
So solder in the out put transistors properly.

Don't worry, if u follow me, u will be fine.

Just put everything back together...and post back. Do not power up.