PCB Help TVS Chip

Postby LoboX » Fri Sep 06, 2013 1:20 pm
Hi i am trying to fix a WD hdd, if i plug the power, the drive doesn't do jack, so first place to look TVS CHIP.

1) If i have faulty TVs chips, and i try to test the voltage of both chips, and i get a voltage reading that means the chips are working? Do i still need to remove them?
2) If i remove the 2 chips and still the hdd doesn't turn on, what else could be the problem?
3) I know i can use another PCB to test hdd to see if it turns on, what can i do if the hdd that i have the connection of the spindle doesn't match the hdd i am trying to fix anyway around this.

Any tips would be great just learning a couple of things here, Data is not important i am just curious to see how this works.

Thanks

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Data Recovery in the Dominican Republic
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See http://www.users.on.net/~fzabkar/HDD/TVS_diode_FAQ.html

... and http://www.users.on.net/~fzabkar/HDD/bi ... diodes.jpg


Why would you remove something that is working?


You would need to make some additional measurements.


The 88i6745 MCU contains embedded data that would need to be transferred to your donor. Alternatively, you would need to retrieve these data from the System Area in a reserved section on the platters.

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A backup a day keeps DR away.

Thank you for that link and picture i understand better now. One thing tho.

1)You would need to make some additional measurements. If I removed the diodes and i still have the problem, what else can i verify before i purchase a donor PCB.

Thank you for your help really appreciated

_________________
Data Recovery in the Dominican Republic
https://www.recuperamidata.com/

I would measure the voltages of the onboard supplies. That would help me understand the nature of the fault. My next step would depend on the results.

So what have you found so far?

_________________
A backup a day keeps DR away.

Hi, OK i have found another triangle PCB, i have test the bad hdd with the good PCB to see if i get power, and i did the bad hdd turn on, and then turn off i know that is whats going to happen cause of the FW. Now my main goal is trying to fix the Bad PCB, to see why is not giving power to my hdd.

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Data Recovery in the Dominican Republic
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Hi i am testing with the multimeter, and found something odd, i am testing the connector that gives power to the spindle and for some reason in the Good PCB it beeps and on the Bad PCB it doesn't, maybe this is my problem?

The bad PCB Is not receiving power there?

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Data Recovery in the Dominican Republic
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OK now i am confused i took another hdd Samsung and i was checking the same connection i check in the last pic i posted, it didn't beep, but it turned ON the Samsung drive. Hmmm

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Data Recovery in the Dominican Republic
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Did you measure those test points with the PCB mounted on the drive?

What measurements did you get in step #1?

_________________
A backup a day keeps DR away.

Hi again and thank you for trying to help me, OK the test i have been doing are without the PCB mounted on the hdd, i just took the PCB from the hdd and starting testing the points on the PCB. I have been reading the FAQ about diodes and none went to 0.0, so i guess they are OK one thing tho the TVS Chips are diodes right? what about the other small electronic pieces ex:R67 or R64 are those diodes too?

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Data Recovery in the Dominican Republic
https://www.recuperamidata.com/

OK i have posted a pic of the bad PCB with the TVS Chips "Diodes" removed, still same problem no power one thing are those mark electronic little chips are diodes too?.

Thank you.

_________________
Data Recovery in the Dominican Republic
https://www.recuperamidata.com/

Sorry, I don't think I can help you. I don't mean to offend, but your questions suggest that you may be way out of your depth.

_________________
A backup a day keeps DR away.

No problem man, if you cant help that's , too bad yeah sorry about my questions i was just curious to know, not offended bro trust me, I am learning and i know it will take time, I really appreciate the help that u have giving me already

_________________
Data Recovery in the Dominican Republic
https://www.recuperamidata.com/

Here's a primer that might help get you started. Perhaps start at the beginning.

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Sabo Computer Repairs & Data Recovery

Wow nice link, thank you LarrySabo i will start reading

_________________
Data Recovery in the Dominican Republic
https://www.recuperamidata.com/