Toshiba MK6465GSX HDD2H81 stays busy

[odedshankar]

Hi Guys,

I’ve got a Toshiba MK6465GSX HDD2H81, Please see images attached.
The customer advised that the laptop it was in got some liquid spilled and stopped working.
I connected the drive and it looks like the PCB is not responsive and has some shortage on it.
I have a donor drive here but trying to see what would be my best method as i am not that familiar with Toshiba drives.

I have few questions in regards:
1. Is there a TVS chip in similar to 3.5” drives that i can remove to check if it will resolve the problem?
3. Does the PCB of a donor need a ROM transfer from original drive?
4. Where is the ROM in this drive?

Attachments

[pcimage]

ROM chip is "IC602" which contains data that is totally unique to each drive.

Be warned that these are particularly difficult chips to remove, and if it gets broken then it's pretty much "game over"

[odedshankar]

You are right, I had bad experience with 1 attempt i had with a similar chip with hot air gun, the pads just melted out of it. These chips are harder to solder/desolder than the standard ones.
Do you use some other technique with these ones?

[fzabkar]

Measure the resistance of the fuse marked "S" near the +5V SATA power pins.

Measure the voltages between ground and each of the L2 and L3 coils. These will be the Vcore and Vio supplies.

Try reading IC602 in situ using an SOIC clip and programmer. Before you do this, confirm that there is no short between Vcc and ground (pins 4 and .

[odedshankar]

Thx for the info guys.
The S fuse was shorted but repairing it didn't help so more components were out of the game with the original PCB so i decided to swap the ROM.
All good now, i managed to repair the drive and currently imaging the data.
This one was a real pain - ooohhhhhh sweating a lot today.
I found an old WD PCB with similar chip and practised on it.
Than I transferred the ROM into the donor PCB and the drive got power but now it had buzzing sound, so I opened it in a clean room and found that there is stiction condition.
I released the heads from the platters carefully and closed the drive, connected it to the DDP and it is working, beautiful.
It is currently imaging without any bad sectors so far.

I used 350 degrees on the rework station hot gun, the trick with this type of ROM is to heat it in a circular way around it for quite a while carefully from about 0.75mm distance and heat a lot also the centre of the ROM chip as it is using a plate of solder in the middle to attach it to the surface.

Cheers,
Oded

[fzabkar]

The S fuse was shorted but repairing it didn't help ...

How did you repair it, and why do you think that a shorted fuse needs to be repaired?

[odedshankar]

i just ran a wire between the 2 points.
In many cases that i see, mainly with 3.5 it solves the problem in addition to removing the TVS so i thought i'll give it a try but it didn't work.
So it was faster to replace the ROM instead of starting to debug the PCB which never works for me.
The key here is to give the customer the fastest resolution and replacing the ROM did it.

Cheers

[thatdellguy]

The S fuse was shorted but repairing it didn't help

I hate when fuse's get shorted.

i just ran a wire between the 2 points.

I definately would not risk preamp damage over a simple circuit board problem. A replacement S fuse maybe costs 5cents and new heads $75 to $150 dollars.

These chips are harder to solder/desolder than the standard ones.

Extremelly easy with a preheater and flux.

[odedshankar]

I hate when fuse's get shorted.

True true

I definately would not risk preamp damage over a simple circuit board problem. A replacement S fuse maybe costs 5cents and new heads $75 to $150 dollars.

Where do you but these fuses and do how do you know the required specs? just measure it?

Extremelly easy with a preheater and flux

I agree now, after i practised on it, as usual it is all a matter of training

[fzabkar]

i just ran a wire between the 2 points.

If a quick test with a multimeter told you that the fuse was shorted, then a wire would not have been necessary. A good fuse is meant to be "shorted", as is a wire. OTOH, if the fuse had been open, then that would have warranted further examination.

In your case bridging an open fuse would not have been advisable since there appears to be no TVS diode or any other protection device. A TVS diode usually limits the damage to itself by going short circuit and taking out the fuse, in which case removing the diode will remove the reason for the short. However, an open fuse, in the absence of any other protection device, would point to damage elsewhere on the PCB. That said, some PCBs are known for open fuses which appear to be due to fatigue rather than genuine faults. Some testing with a multimeter, with the PCB removed from the drive, would have provided quick confirmation.

[odedshankar]

thx for the info fzabkar.
I did meant "open" and not shorted, bad wording from my side sorry for the confusion.
I understand now what you meant and will remember that for future cases.

Cheers