# Alpine MRV-1507 help



## jeffp (Jan 18, 2015)

Hi everyone, I have been working on this amplifier and have gotten it working. 
One thing that I am not sure about though. The protection light blinks red. The manual says RCA floating.
When I first got this unit working I was using a 7909 and the light was green. Then I used a 7990 head unit and the light would blink red. Going back to the 7909 it was green again.
So I just assumed the 7990 had floating rca input audio.

I just got a 30th anniversary 7909 (unit 230 of 300) and powered the amp with it and the light is blinking red again.

So I am not sure the unit is working correctly or not. The manual is not clear to say there is a problem, the amp works perfectly except for the blinking protection light. I have looked at the schematic and have not been able to determine if there really is a problem or not. 
So any help would be appreciated on this one. 
I do have a second amp I have to repair to make a comparison with, but I would like to know for sure from someone familiar with this amp.

REGARDS:

Jeff Priddy


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## jeffp (Jan 18, 2015)

Ok, sorry guys, I figured it out. 
Apparently, the jumper wire I have been using to power my head unit has excessive resistance, no enough to make the head unit not work correctly, but enough resistance to fool the amplifier into thinking the RCA line cables were not hooked up to the amp.
I chased my tail around for a number of hours on this. 
I have had problems with similar jumper cables, store bought clip jumpers, so once again it is still best to build your own jumper cables for testing electronics.
Glad I figured it out, wasted a good amount of time in the process though.


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