Toshiba MK1234GSX PCB Issue

[fzabkar]

I don't mean to offend, but are you measuring the resistances with power applied? You should perform these measurements in the absence of power.

In any case, can you now measure the voltages at the requested points?

[Dizidago357]

No offense taken. But yes, I am measuring without power.

What level should I measure the voltages at? And also, would I measure with simply ground on one end of the component and hot on the other side, or does ground need to be elsewhere than on the component I'm measuring?

Dizi

[BlackST]

@Dizidago357

In my opinion, all these measurements on the "dead" pcb will lead you to nowhere, neither random replacements of SMD components without schematics and knowing who makes what on the circuit (less than less if you need replacement parts different from passive SMDs) . If you have a decent multichannel oscilloscope, it's time to put it at work. When it's not "fuse and minor stuff" problem, some more effort and gear is absolutely needed.

Your problems are either a broken / malfunctioning MCU or a broken / malfunctioning section (maybe 2) of the PCB preventing the drive from starting.

0) Check motor and VCM and check for absence of mechanical trouble (just in case and for later safety)
1) Check MCU for functionality.
2) If MCU is still working, check internal ROM for correct content.
3) Make another PCB work with patient HDA (see point 2) .
4) If still no joy there is additional damage to preamplifier / headstack.

To perform 1) you need a lot more than a multimeter and probably if one specific part of your PCB is broken you need to make some modifications.
To perform 2) you need the usual specialistic equipment , eventually having the BGA chip moved to a "test" PCB. Probably it would be sufficient
To perform 3) you need 2) and the necessary equipment (and if works, you have data)
Point 4) should be the less problematic part.

After this (or if it cannot be done), I see no alternative to outsourcing (as the thread started on April, 12 maybe it was not urgent)
Only if you are very luck and the problem turns to be minor (but you still haven't found it !!) you can make it work.

Just my 20 EURO....

[fzabkar]

No offense taken. But yes, I am measuring without power.

What level should I measure the voltages at? And also, would I measure with simply ground on one end of the component and hot on the other side, or does ground need to be elsewhere than on the component I'm measuring?

I find your results very confusing. The DC resistance of a coil is less than 1 ohm, so if you are measuring 85 ohms to ground on one side, then you should be getting a similar reading on the other side. The fact that your readings differed suggested to me that the coil on your donor board was open circuit. This begs the question, why did you transfer a suspect coil to your patient PCB? In short, there is something very wrong with your measurement procedure.

Anyway, when measuring voltages, connect your black (COM) probe to a SATA power ground pin, and the red probe (Volt/Ohm) to the point being tested. I suspect you should be looking for +3.3V and ~+1.2V, so select the appropriate range on your DMM (20VDC and 2VDC). Practice with a 1.5V alkaline battery and a 3V lithium coin cell battery if you feel uncomfortable with this. Be careful not to slip with your probes, as serious damage may result.

[fzabkar]

@Dizidago357

In my opinion, all these measurements on the "dead" pcb will lead you to nowhere, neither random replacements of SMD components without schematics and knowing who makes what on the circuit (less than less if you need replacement parts different from passive SMDs) .

Any decent tech can check the functionality of the power supplies without a schematic. Such a task is no more difficult than locating the pedals and gear stick in an unfamiliar car.

If you have a decent multichannel oscilloscope, it's time to put it at work.

Let's wait until the OP provides the requested measurements before breaking out the CRO.

[BlackST]

Sure have to wait !! MCU is still unknown if it works or not.

[VoodooPL]

Guys, what if the MCU doesn't work due to damage, is there any other way to copy CP's from patient PCB ?
I've got MK6034GSX with very similar problem - drive remains BSY. I'm sure it's related to PCB because heads and bearing work good.

[BlackST]

If it is unresponsive thru the interface the options are few, but you still can do something. It depends from case to case - note : these case do not like urgency.

[VoodooPL]

The drive no.1 is: IT DOESN'T WORK - remains in BSY
HDA: donor
PCB: patient
Heads: donor
Platter: patient

The drive no.2 is: - IT WORKS
HDA: patient
PCB: donor
Heads: patient
Platter: donor

After leaving the drive no.1 powered-on for about 10 minutes in BSY state, after mentioned 10 minutes it becomes DRD DSC and of course it was recognized. First thing which I made was copying the CP's.
I've copied all CP's except DD to donor PCB. After connecting donor PCB to drive no.1 it still spins up but remains BSY, have You got any suggestions, how to make it work?

[nande]

maybe glist problem.

[VoodooPL]

In fact You are right nande, after clearing G-List, the drive starts normally.
SMART looks fine.
But when trying to read data problem occurs it works very slowly:
- during "make data copy" it copied about 60 000 LBA in 5 minutes, also some red blocks appeared.
- while entering in Data Extractor, it took some time to reach partition tree with its contents, and after that a few errors appear.



What do You think it could be? bad sectors?
SMART looks really good, I've performed logical test - surface verification and its approximate speed is beetween 65-70.

[nande]

How about reverse clone? Have u tried?

[VoodooPL]

Thank You nande for hint, it helped me.
I've made successfully "make data copy" backwards, and the data are save now
However, what do You think about this Toshiba drives? I've noticed that after the copying process was finished, I've powered it off and on again, the drive became DRD DSC immediately (the PCB and spindle was warm) but when is cold it stays BSY for about 10 minutes.
Does it mean that bearing could be damaged? what do You think guys?