Rockford T1500-1bd BD_MUTE

[Tom7227]

Working on a RF T1500.1bd amp,

I am finding that I have the proper waveforms coming out of the BD output card (pin9+10), they reach the LM5110 inputs, but there are no outputs on either IC.

I find the BD_Mute line low, but I can not see how it's generated, any ideas?

 

[Tom7227]

Replaced both LM5110 and fixed the problem

This amp had a lot of small wires that scattered all over the PCB, came from the speaker terminals. Wish that had a better design.

 

[Hexhclass]

What is the full part number on the original LM5110 IC?
What kind of wave form should be on Pin 9 and 10?
I have an amp with almost the same problem.

 

[Tom7227]

The lm5110 is an 8 pin IC, pin 9 and 10 of which ic ?

 

[DArends]

ian33 is referring to the sound cards wave form on pins 9 and 10. Would they be the square and triangle wave forms?

 

[Tom7227]

Ok, the output of the BD card Pin 8+9 (not 9+10) are square waves, both present, They are named Toggle A and Toggle B.

They drive thru a 1K resistor, into Pins 2 and 4 into the Lm5110 (IC 2000 + IC2002). I had the proper waveform coming out of both 8+9 of the BD drive, and arriving at the IC's, but no output from Pin 5 or 7. I thought it was the BD_mute line causing the IC not to be enabled BUT, I replaced both IC's and the amp worked. SO it was a bad IC that was causing the issue.

There are also 2 SMT diodes D2000 and D2017, that enable the wave form to allow the pulse to reach the IC.

I never found where BD_mute came from, I have moved on .

The IC's used are LM5110-1m

 

[Hexhclass]

I will order the IC,what i have in stock is Lm5110-3


thanks for the info

 

[seankane]

I also stock the LM5110-1m

I used this as a replacement in a p1000-1bd and its been in service for over a year now with 0 issues.

I have never tried the 3 version.

What is the difference? Have you compared data sheets?

 

[DArends]

Is there any way one of you guys could help me out with a service manual for it?

 

[Hexhclass]

I think base on the configuration of the circuit -3 will be inverting and -1 will be
non-inverting if used.