Hi,

I have a defective drive Samsung HD642JJ rev A, 16M with controller board Trinity R006M rev05, BF41-00184B. See included photo. When powered up, the drive does absolutely nothing, no clicks and remains ice cold -> seemingly draws no power. There was no incident, it just failed at power-up.

I measured voltages at several points on the board. Both 5V and 12V are OK 'downstream' of the diodes. However, voltages at the DC/DC converter coils are way too low (only a fraction of a volt) -> motor control chip (TI SH6125B, left hand side) defective?

Replacing the TI chip seems almost impossible because of the extremely tightly spaced pins. And it may be another component that fails. A board swap is much simpler and surer.

Before ordering a replacement board I'd like to know if a board swap is sufficient. I read on this forum that some drives have a ROM that contains configuration data, others have these data on the drive itself -> some need a ROM change, others not. There is a small 8-pin IC on the board but I don't know if it's a ROM.

Anyone who knows more about the Trinity boards?
Thanks in advance.

Seems that the 8pin ic is not the rom.
The BGA chip may have the rom integrated into it.
The TI chip , with the proper tools, wont be much of a problem to replace.
(but not by an user without proper chip soldering experience).
But before replacing any components, proper diagnosis and isolation of the fault will be
necessary by checking the inputs to the TI .(using multimeter /osilloscope)
Not a job for an inexperienced user, though you dont seem like one

8 pin chip is a chopper, part of DC-DC converter.

My suspicion comes that PCB drawns no power. How did you meassure voltage? There is a fuse marked 000 just below pair of TVS's. This fuse is serial with ground. If it is blown, you can still meassure proper voltage, depends where you put negative lead.
I suggest disconnect from power and do proper continuity check for fuse, and both TVS's. Use the lowest possible range (200 Ohms). It might be other fuses which look like resistors.

Thanks for the info. Didn't know the fuse was serial with ground, assumed it was Vcc. I always measured voltages with minus side of multimeter attached to drive chassis.

I now repeated measurements as you indicated (power disconnected, 200 ohm range). Results:
- both TVS (top right on photo): infinite
- zero ohm fuse (just under TVS): zero
Same result with plus/minus wires interchanged.

Is this the expected result?

PS: I'm really in the dark since I have no board schematics nor pinout diagrams of the ICs.

Thanks for yr help
Paul

the readings you got are ok
more info on TVS DIODES are here..

http://www.users.on.net/~fzabkar/HDD/TVS_diode_FAQ.html


Also there are no visible signs of burnt/failed components on the logic board to give you further hints to solve your problem.

I dont think this is a DIY without proper tools and knowledge.
An identical logic board may spin up the drive, but may not detect the drive,
and there are chances that the working board may get damaged.
Is it worth the trouble,you have to decide.
if data is important, take DR help .



.

Yes, your readings are correct. As expected from a good board. Unfortunately as you say there is no schematics. Next step would be checking +/-5V voltage for preamp, and there is couple regulators for MPU core and RAM. It needs tracing connections to known points and having working PCB of the same type, helps a lot.