i recently purchased a nad 3020 series 20 amp that was not working,mainly to see if i can get it going, a good learning tool for me, the problem is i am way confused.The service manual i have for it lists different components than what is installed, actualy they more match the 3020A, but even this isnt totaly acurate, so i am wondering if someone else messed about with it before me, which is very possible i guess.so i am at a loss which service manaual to use.should i totaly believe the original?.The other real issue is the little LED board that is installed.when you look at the parts list it shows for example that D803 should be a diode, but is in fact a 2w-680 ohm resitor, and C807 should be a capacitor, but looks like a diode
the service manual only goes up to C805.see attached.So as you can see i am a bit confused .com.
I have attached photo of the board and the 2 alternative parts lists
Appreciate any help or comments you may have, thanks, paul.
the service manual only goes up to C805.see attached.So as you can see i am a bit confused .com.
I have attached photo of the board and the 2 alternative parts lists
Appreciate any help or comments you may have, thanks, paul.
Attachments
You should use a DMM like that. Multimetre numerique professionnel, DMM, tension cc, courant, capacite Ohm, hFE, amperemetre, voltmetre, testeur Portable | AliExpress You will see if it is a diode or a capacitor
C807 could be a tantalum capacitor .
The resistor replacing the diode in the diagram I am looking at feeds the string of LED,s attached to the LB1405.
It says 6V AC in with 7.64 out to feed them ---you can get AC operated LED,s but all this is supposition .
If you are looking at a diagram that only goes up to =C805 then either you have the wrong version or somebody has modified it.
The resistor replacing the diode in the diagram I am looking at feeds the string of LED,s attached to the LB1405.
It says 6V AC in with 7.64 out to feed them ---you can get AC operated LED,s but all this is supposition .
If you are looking at a diagram that only goes up to =C805 then either you have the wrong version or somebody has modified it.
hi and thanks.Now i already have a copy of this and one of the attachments has the components list that applies to this manual.Now you would assume, as i did to start with that this list applies, but here is my confusion,if you look at the pcb picture i put up on here the diode (803) clearly isnt (its a resistor),and the capacitor (807) looks more like a diode, and tests out like one as well.
if you check out photos on the web of others like it, they also have a resistor in the same position.so here is my problem, do i rebuild it as per the manual, or as it is in front of me? many thanks
if you check out photos on the web of others like it, they also have a resistor in the same position.so here is my problem, do i rebuild it as per the manual, or as it is in front of me? many thanks
I rebuilt a 3020A last year and my board was configured the same way. I left it as is. It's only for the light show and it was functional as configured.