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hi
i am a student and i have a video sender that its frequency as the producer said, is 1.2ghz and its not working any more, i want to repair it but the ic part number is removed by producer, can you suggest me any part number for this sender?
That looks quite complicated compared to most senders on the market.
First, don't assume the unmarked IC is faulty. It could be, but they are very reliable.
Does it have power to all parts?
Is it producing any output at all?
If it produces an unmodulated carrier, the problem is the modulator not the PLL.
If you are sure the IC is at fault, trace the circuitry around and sketch a schematic, it doesn't look very complicated. Then compare the pin-out with known similar devices to find a match. Finally, see if the matched pins are on a device that suits the frequency and supply voltage. My first guess would be it is an LMX2332U or one of that family.
Thank you so much brian, i am almost sure one of this two ic are not working because the current seems to be normal, but i cant see any signal, i dont know any similar one if you know please introduce some, the supply voltage i measured was 2.8 v it have a 7805 and after it there is a component that the smd code is dm61x may be it is a regulator. there some components pictures that i dont know them too and the 8 pin ic is it modulator?
The white square "FJZ" device is a Fujitsu microwave power transistor but the tracks around it suggest this is for much higher frequency than 1.2GHz. Are you sure it isn't for 12GHz?
>> ..the supply voltage i measured was 2.8 v it have a 7805...
If this is the input voltage to the 7805 then it is not enough, you need about 8V min.
If it is the output of teh 7805 then again it is not enough, it should be 5V.
I'd start by looking at the DC power before worrying about the rest.
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