Toshiba MK1234GSX PCB Issue

[Dizidago357]

Hi,

I have a Toshiba model MK1234GSX with a code of HDD2D31 D ZK01 T. With the patient PCB attached the drive does not spin up, but with a donor PCB the drive spins up (but never goes ready). Was wondering if anyone could give some insight as to possible TVS components on the attached photo. I'm thinking D1 may be one, but don't want to remove anything until someone else can chime in and confirm that. No visibly blown components from what I can see under a magnifying glass.

Thanks,

Dizi

Attachments

[CK]

Check "F1"

[CK]

btw....PCB's are not interchangeable on Toshiba drives. They contain "adaptive" data.

Drive will spin but never come ready.

[fzabkar]

There is a 4A fuse, F1, near the SATA power connector.

Littelfuse Surface Mount Fuses, N = 2A, S = 4A:
http://www.farnell.com/datasheets/48294.pdf

There is also a 5V TVS diode at D1.

[BlackST]

8 out of 10 if fuse is blown there is additional damage. DON'T SHORT IT , YOU'LL PROBABLY REGRET IT.

[Dizidago357]

@CK,

I know the adaptives are in the MCU, I used the board swap as a test to see if it was stiction, dead motor, or dead board.

@Fzabkar,

What should those two fuses be measuring at when drive is powered off?

Regards,

Dizi

[fzabkar]

Dizidago357, let me know if you are prepared to take some simple measurements. This will verify whether there are any shorted loads on any of the onboard DC-DC converters.

BTW, these SMT fuses are known for nuisance tripping. If F1 is open, but D1 is intact, then I would suspect that the rest of the board should be OK.

As usual, good luck.

FYI, I've been reverse engineering quite a few boards lately. I'm finding that a flatbed scanner set to 1200 dpi gives excellent results. I'd be happy to do yours in my free time. You could upload your scans to a file sharing service if space doesn't permit uploading them here. In my case, each scan, front and back, occupied about 2MB. If you butt the boards against a corner, with the interface connector against the top edge, this makes it easier to flip between the front and back sides of the PCB, particularly when you are following the traces on either side of a plated thru-hole.

[Dizidago357]

@Fzabkar,

I believe we have a multimeter in the office, I'll just have to dig around for it in the morning when I'm in (it's probably still in boxes from the recent move). When I find it, what settings should I employ and what measurements am I looking for?

Dizi

[fzabkar]

I'd set your DMM on the 200 ohms range. Measure the resistances of F1 and D1. If D1 is shorted, remove it with flush cutters.

Now measure the resistance between ground and each side of F1. This will tell us if there is an excessive load on the +5V supply.

Measure the resistance between ground and the 4R7 coil (L106). This will test for a short on the DC-DC converter consisting of L106, Q10, and D9. I suspect it provides the Vcore voltage for the Marvell MCU.

Also test the resistances between ground and each of the pins of Q9. I suspect that Q9 is the pass transistor in a linear supply, probably supplying the Vio for the MCU and SDRAM.

If all is OK, then the next step will be to measure the voltages at F1, Q9, L106, and the preamp connector, PJ2.

[ROb]

Rarely D1 goes !!
Replace F1 and you can get going.
Else do follow what fzakbar has to say

[Dizidago357]

Was finally able to locate the multimeter not too long ago, and after some time reading up and refreshing myself on something I haven't done in years, I've got a few results.

On both donor and patient F1 I get 00.3
On donor and patient D1 (Red to Yellow) I get OL.
On donor D1 (Green to Yellow) I get around 196.
On patient D1 (Green to Yellow) I get around 198.

Does this difference on D1 give any indicator?

For D1 measurements (specifically Green to Yellow), would the polarity matter? With ground on Yellow and positive on Green, I got the above results. But with them switched (ground on Yellow, positive on Green) I received OL on both boards.

Can you please advise which are the grounds for the other chips? I haven't done any multimeter work since electronics class in high school

Dizi

Attachments

[fzabkar]

F1 and D1 both test OK. The difference between your two boards is insignificant. The different result for reverse polarity is to be expected for a diode because it conducts in the forward direction but not in the reverse direction.

For your other measurements, you can use the ground pins in the SATA power connector:
http://pinouts.ru/Power/sata-power_pinout.shtml

[Dizidago357]

Hi,

Results on the tests from the ground pins in the SATA connection to the various components:

Patient Board
F1 Left: OL
F1 Right: OL
L106 Top: OL
L106 Bottom: OL
Q9 Top Left: OL
Q9 Middle Left: Starts at about 6 or 7 then increases until it rests on OL
Q9 Bottom Left: Starts at about 6 or 7 then increases until it rests on OL
Q9 Top Right: OL
Q9 Middle Right: Starts at about 6 or 7 then increases until it rests on OL
Q9 Bottom Right: Starts at about 6 or 7 then increases until it rests on OL

Donor Board
F1 Left: OL
F1 Right: OL
L106 Top: Hovers around 85-86
L106 Bottom: OL
Q9 Top Left: OL
Q9 Middle Left: OL
Q9 Bottom Left: OL
Q9 Top Right: OL
Q9 Middle Right: OL
Q9 Bottom Right: OL

All relative locations are looking at the component side of the board with the SATA connector at the top.

Is the L106 possibly bad on the patient, and as a result excess electricity is getting through to Q9 (causing those readings to be different)? If so, should I attempt to replace the L106 component, or is there more testing necessary?

Dizi

[fzabkar]

If anything, the coil is bad on the donor, assuming you've performed your measurements correctly. The DC resistance of your coil should be close to zero.

I don't understand why Q9 tests differently on the patient board. In any case nothing appears shorted on the patient, so it should be OK to measure the voltages at Q9 and L106. I'd use the neighbouring plated through-holes as the test points, rather than the pins on Q9.

BTW, I'm assuming that you are looking at the PCB with interface pins facing upwards, not to the left as in your photo.

[Dizidago357]

Fzabkar,

I am taking measurements with the PCB component side up and the SATA connectors are rotated to the top (and not to the left, as in the picture). Just to clarify, I take measurements from the component side, not on the reverse side through the holes, correct?

Dizi

[fzabkar]

Just to clarify, I take measurements from the component side, not on the reverse side through the holes, correct?

Yes.

[Dizidago357]

Thanks. I'll swap L106 coils and provide a response at some point tomorrow.

Dizi

[BlackST]

Don't forget to CHECK and protect what's after and around the ... 'coils'... or when you power up again you'll hear the famous hit 'SMOKE GETS IN YOUR EYES' - - in a few words you make more damage and something else blows. And still don't know if MCU works...
P.s. If you fry the mcu what was a relatively simple task will become an expensive recovery.

[Dizidago357]

Well, the swap went fine. However both boards still have relatively the same measurement results. Just for kicks, I tried both drives and the donor drive with the patient L106 spins up and IDs, while the patient drive with the donor L106 still does not spin. There must be something else wrong with the patient board - my guess is something else either before or after the coil is blown. I'm going to try a hotswap (although typically in my experience, that procedure doesn't work often for Toshibas), but any other suggestions?

Dizi

[Dizidago357]

No go on the hotswap. Was pretty sure it wouldn't work, but no harm done trying.

Dizi