othello999
New Member
Hi, can anyone help me to identify the values of L400 and L402 inductors on the Logitech Z-2300 motherboard? they are located near TDA amplifiers. Thanks in advance.
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I couldn't find any information in the TDA7296 datasheet about these inductors and that's why I came here to seek helpDoesn't the datasheet for the TDA amplifier ICs recommend the value of inductors?
None of us can find information on your mother board.Hi, can anyone help me to identify the values of
No, it connects to the third (3) pin (NON INVERTING INPUT)of the TDA7296 amplifier. So I presume that it works like a LC filter.ST Micro does not recommend inductors for the TDA9296 amplifier IC. Maybe Logitech uses the inductors in a different part of the circuit.
Well because I needed to replace a bad TDA7296 amplifier, but on the PCB there were lots of glue. While I tried to remove metal plate which pins all 4 of the TDA amplifiers to the radiator (which was also glued to the PCB) , I accidentally removed it with the glue and in it were two inductors.... so now I need to find their nominals so I could replace them...None of us can find information on your mother board.
A good close up picture might help.
BIG QUESTION: why? why do you need information?
Sorry if I have mistaken you, but you get my point now and that's what matters.I can't see any components on your picture that look like inductors. It would have helped if you had said that this was an amplifier rather than describing it as a motherboard. I assume others (As I did.) assumed you were talking about a computer mother board.
Edit. After seeing Nigel's reply It looks like the option of fitting these components was not used. What is the fault an you equipment ?
Les.
Exactly, this is a small toroidol inductor with ferrite core.That looks more like a ferrite bead on a piece of wire rather than an actual inductor.
If the datasheet doesn't show an inductor, then it probably doesn't need one.
I would suggest drawing the circuit of the output stage out fully, and comparing it to the datasheet.
Also you can't see these inductors, because they are ripped off (my mistake for trying to remove glue without inspecting what's underneath it first)I can't see any components on your picture that look like inductors. It would have helped if you had said that this was an amplifier rather than describing it as a motherboard. I assume others (As I did.) assumed you were talking about a computer mother board.
Edit. After seeing Nigel's reply It looks like the option of fitting these components was not used. What is the fault an you equipment ?
Les.
Exactly, this is a small toroidol inductor with ferrite core.
I think that these form a RLC low-pass filter. So the audio signal comes from dual operational amplifier (4565 IC) then passes the RLC low-pass filter and afterwards travels to TDA7296 amplifiers input. So if I would replace these small inductors with a peace of short wire, wouldn't the signal be distorted?
The Logitech Z-2300 speaker system has a subwoofer and two low power satellite speakers. The TDA7296 amplifier ICs drive the satellites with mid-range and high audio frequencies. Maybe the inductors are part of the crossover frequency dividing system (high-pass filters, not low-pass filters). Without a schematic we are just guessing. If the inductors are part of the crossover then removing them will cause low frequencies to destroy the tweeters.