Rockford 1501bd >>> Problems e service manual

[TasoTaso]

..or before changing the TL072 is it better to measure their power supply?

 

[Perry Babin]

#20:
There are VERY few legitimate sellers of semiconductors on ebay. These MAY be OK but I'd suggest buying from a reputable distributor.

#21:
It would have taken less time to measure the voltage than the time it will generally take to get a reply.

 

[TasoTaso]

I have not measured the tension because I'm always afraid of doing damage and I do not know what values I have to find.
if it is useful, proceed to measure it.
what tensions should I have? from datasheet i don't understand if +18v or +15v (between GND and + VCC?)

Thanks again.

 

[Perry Babin]

Black probe It's just like when you measured the offset, it's just different pins. I think the voltage will be about ±10v. Pins 4 and 8.

 

[TasoTaso]

ok I listen to your advice I buy on a serious site with certified material (they assured me over the phone). I buy on RScomponents ...... But I see different models .. what should I take from this list?

Amplificatori operazionali | RS Components

I see that there are many different models!

Thank you

 

[Perry Babin]

TL072CD Texas Instruments

 

[TasoTaso]

Hi, i have measured after 2 minutes switch on amplifier.

On U1 U2 U3 i have V- and V+ ...13.4v and 13.2v.
On U4 i have on V- 9.2v and on V+ 10.5v.

Is all normal?

Proceed to the change of 4 operational?

Thanks for assisting me! 😛

 

[Perry Babin]

The supply voltages are OK.

Start with replacing U2 and see if that solves the problem.