TDGAUDIO NFC-83A ceiling speaker crossover repair(no output)

[r2digital]

Hey guys, im trying to figure out why my ceiling speaker has no output from the woofer or tweeter. I cannot seem to get a resistance at the main input speaker terminals but i did measure resistance at the woofer and at the tweeter wires individually and everything seems to be OK. Ive done a little bit of troubleshooting on my own and when i was probing the negative terminal in combination with any component (PTC fuse, the capacitor, and any of the resistors) on the crossover i get no continuity what so ever. However, when i take the same model speaker but a fully working one and i probe the negative terminal in combination with any of the components listed above i get continuity. What section of the crossover would cause a no output condition? I've been toying with the fact that its the PTC resettable fuse but i am unsure if its used to only protect the tweeter or if its used to protect the entire design.



Join Date: Aug 2010
I checked all the resistors and the values are as follows

25w2ΩJ=1.5
25w2ΩJ=1.5
10w2.2ΩJ=1.4
10w2.2ΩJ=1.4
10w2.7ΩJ=2.8

[stj]

Re: TDGAUDIO NFC-83A ceiling speaker crossover repair(no output)

thats a stupid design, the vibration will fuck the soldering.
check the joints on the back of the board.

[r2digital]

Re: TDGAUDIO NFC-83A ceiling speaker crossover repair(no output)

I will touch up and reflow all the joints on the back of the PCB. Do the resistance values seem correct? When i check the resistance values of the same model of a working speaker the results are much closer to their rating.
For example the
25W2ohmJ=2.2ohms
10W2.2ohmJ=2.3

Should i be concerned the the different values on the non working speakers?

[r2digital]

Re: TDGAUDIO NFC-83A ceiling speaker crossover repair(no output)

looks like some one already got to the PCB before me. Lots of deep scratches on the pcb. I think maybe one of them is deep enough to cut a trace to the negative post?


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[petehall347]

Re: TDGAUDIO NFC-83A ceiling speaker crossover repair(no output)

the thermistor is there to protect the tweeter .

[r2digital]

Re: TDGAUDIO NFC-83A ceiling speaker crossover repair(no output)

Does anyone what i should check if i have no output from the tweeter/midbass? Verified the tweeter and midbass work fine individually

[stj]

Re: TDGAUDIO NFC-83A ceiling speaker crossover repair(no output)

draw the circuit.
it doesnt look like a crossover though - only one cap.