Author Topic: Network cable tester fault seeking help  (Read 224 times)

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Offline daisizhouTopic starter

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Network cable tester fault seeking help
« on: January 02, 2025, 04:21:31 am »
Network cable tester "Smart Mouse" NF-168,Fault in wiring function.
Upon inspection of the motherboard, it was discovered that one U4 chip was damaged.
Unfortunately, the model has been erased. Does anyone know what type of chip this is?
daisizhou#sina.com #=@
 

Offline BreakingOhmsLaw

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Re: Network cable tester fault seeking help
« Reply #1 on: January 03, 2025, 07:23:53 pm »
Probably this is just a button, connected to a binary counter, connected to a BCD-to-n decoder. 74LS145 or equivalent.
 

Online wraper

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Re: Network cable tester fault seeking help
« Reply #2 on: January 03, 2025, 07:29:15 pm »
To me it looks like a drop of rosin flux, not damage. You didn't say what's an exact issue but 455kHz ceramic resonator present on PCB is quite fragile and often fails when device is dropped.
 


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