PCB electrical check best practice
August 5th, 2013, 2:43
Hello,
can someone point me to a guide with the best practice to test a pcb for Electrical Failure of the board components ?
In particular I'm looking for information on Samsung drives.
Thank You
can someone point me to a guide with the best practice to test a pcb for Electrical Failure of the board components ?
In particular I'm looking for information on Samsung drives.
Thank You
Re: PCB electrical check best practice
August 5th, 2013, 3:16
(1) Inspect the board for visual damage.
(2) Does the drive spin up? If yes, PCB is probably OK. If not, PCB is probably bad.
(3) Check the TVS diodes and protection devices (fuse, polyswitch, zero-ohm resistor).
(4) Check onboard regulators for correct output voltages. Test for shorts on the outputs. If there is a short on the negative preamp supply, disconnect PCB from HDA and retest. If short goes away, then preamp is dead.
(5) Connect to the board's serial console. Is there any output? If yes, then MCU is working, at least partially. Are there any diagnostic messages? Error messages?
(2) Does the drive spin up? If yes, PCB is probably OK. If not, PCB is probably bad.
(3) Check the TVS diodes and protection devices (fuse, polyswitch, zero-ohm resistor).
(4) Check onboard regulators for correct output voltages. Test for shorts on the outputs. If there is a short on the negative preamp supply, disconnect PCB from HDA and retest. If short goes away, then preamp is dead.
(5) Connect to the board's serial console. Is there any output? If yes, then MCU is working, at least partially. Are there any diagnostic messages? Error messages?
Re: PCB electrical check best practice
August 6th, 2013, 10:21
fzabkar wrote:(4) Check onboard regulators for correct output voltages. Test for shorts on the outputs. If there is a short on the negative preamp supply, disconnect PCB from HDA and retest. If short goes away, then preamp is dead.
Where I can find a scheme for the correct location of those elements ?
Re: PCB electrical check best practice
August 6th, 2013, 10:35
You could do your research backwards, meaning search the web for ANY HDD schematics, then look on HDD donor sites or ebay for that hard disk.
other way round likely to turn your hair as grey as my beard.
other way round likely to turn your hair as grey as my beard.
Re: PCB electrical check best practice
August 6th, 2013, 10:36
Since schematics are not available, I generally use a Huntron to compare the signatures of a good with a suspect PCB.
Re: PCB electrical check best practice
August 6th, 2013, 12:49
I go all warm and fuzzy when folks mention engineering solutions and test gear 
<ahem> anyways .....
OP:
You could also try looking up other contributions and tutorials from fzabkar
Pure quality.
Kern
edit: HaQue, greybeard ..... oooh there's a nickname a brewin =)
<ahem> anyways .....
OP:
You could also try looking up other contributions and tutorials from fzabkar
Pure quality.
Kern
edit: HaQue, greybeard ..... oooh there's a nickname a brewin =)
Re: PCB electrical check best practice
August 6th, 2013, 17:56
hdguy wrote:fzabkar wrote:(4) Check onboard regulators for correct output voltages. Test for shorts on the outputs. If there is a short on the negative preamp supply, disconnect PCB from HDA and retest. If short goes away, then preamp is dead.
Where I can find a scheme for the correct location of those elements ?
Tutorial - Linear and Switchmode Regulators used in HDDs:
http://malthus.zapto.org/viewtopic.php?f=59&t=231
Tutorial - how to locate the basic test points of an unfamiliar HDD PCB:
http://www.users.on.net/~fzabkar/HDD/Tu ... 0411N.html
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