Soundstream Rubicon 1.2500 in protect

[bigpun4fubu]

He said it would pulse with rcas hooked up and rumble when unhooked

 

[bigpun4fubu]

Counting from the op-amp end of the driver board, pin 6 should have nearly rail voltage during the mute delay and then drop to near ground when the mute delay ends.

Is this what you see?

How long does it take from the time that remote voltage is applied until the voltage on that pin drops to near ground?

about 3 secoonds it drops to between 10v and 12v then back up to rail voltage fluctuating from 66v to 90 v

 

[Perry Babin]

Between the time that the power supply powers up (producing rail voltage) and the end of the 3-second delay, is there DC present on the speaker terminals?

 

[bigpun4fubu]

yes dc voltage is present

 

[Perry Babin]

Check Q43 on the driver board. It may be leaky. You'll have to remove it to check it.

 

[bigpun4fubu]

Q43 checked good out of circuit . powered up amp with Q43 out of circuit it wasnt in protect

 

[bigpun4fubu]

 

[Perry Babin]

Is Q44 in parallel with Q43? If so, remove it and check it.

 

[Perry Babin]

Does pin 6 go from +rail voltage to ground and remain at ground now (with Q43 out of the circuit)?

 

[bigpun4fubu]

pin 6 reads less than 1 volt with Q43 out of circuit , going to remove Q44 now and check it

 

[bigpun4fubu]

An externally hosted image should be here but it was not working when we last tested it.

 

[Perry Babin]

It appears leaky but it could have been due to you touching the probes. Re-check it. Generally, if there is leakage, there is leakage no matter the orientation of the probes. If there was leakage on test 1, I would have expected it to show up on test 3.

 

[bigpun4fubu]

i didnt touch probes i have clips on my probes to prevent that i checked it 3 times before posting

 

[bigpun4fubu]

it gave same result every time

 

[Perry Babin]

Try reinstalling the one that checked OK to see if the amp will power up normally.

 

[bigpun4fubu]

with Q44 removed amplifier powers up normally

 

[Perry Babin]

Did you reinstall the transistor that was in the Q43 location?

Does it produce audio?

 

[bigpun4fubu]

installed but i will check the audio

 

[bigpun4fubu]

Did you reinstall the transistor that was in the Q43 location?

Does it produce audio?

Q43 installed Q44 removed no audio present

 

[Perry Babin]

Do you have a scope?

If it has a master/slave switch, is the switch set to master?