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Data recovery and disk repair questions and discussions related to old-fashioned SATA, SAS, SCSI, IDE, MFM hard drives - any type of storage device that has moving parts
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3.5" Toshiba's

July 20th, 2015, 11:27

So I just got in my first real live 3.5" Toshiba drive for data recovery. Model is MD04ACA400 which doesn't appear to be supported in PC-3000 even in the latest version. I'm thinking it's either bad heads or G-list damage from the way it's acting, but hard to really know for sure at this point.

Anyone worked on these much yet? I'm assuming that the part number is the place to look for matching parts like the read/write heads and they seem to be available. Even the PCB is quite foreign. No IC602 to speak of, but four similar looking ones labeled IC9-IC12. Anyone know which one(s) contain the configuration pages?

Any help is appreciated, this job is a rush so any input that can cut down my R&D will be a big help.

Re: 3.5" Toshiba's

July 20th, 2015, 11:35

I'm thinking IC10 is the one to transfer if I want to try another PCB, what do you guys think?

I posted a picture here: https://www.data-medics.com/forum/downl ... &mode=view

Re: 3.5" Toshiba's

July 20th, 2015, 12:08

It would be IC10, I think.

Re: 3.5" Toshiba's

July 20th, 2015, 12:28

Update: Solved the case. It was G-List damage as I suspected. Drive has a fair number of bad sectors, but it's imaging away nicely now.

Re: 3.5" Toshiba's

July 20th, 2015, 13:17

Well done.

Nice job :)

Re: 3.5" Toshiba's

July 20th, 2015, 17:08

For reference ...

W25Q80BL, Winbond, 8M-bit 2.5V Serial Flash Memory with uniform 4KB sectors and Dual/Quad SPI:
https://www.winbond.com/resource-files/ ... 80blf1.pdf

LE25U81AQE, ON Semiconductor (Sanyo?), 8Mbit, 2.5V, serial SPI flash memory, VSON8T package:

The LC138 chip (74LC138) is a 3-to-8 Line Decoder / Demultiplexer which enables the MCU to select 1 of the 4 flash memory chips.

It's interesting that the PCB contains 4MBytes of nonvolatile memory. Seems like a lot. I wonder what functionality has been added over previous models.

Re: 3.5" Toshiba's

July 20th, 2015, 18:15

Unfortunately I was only able to get 70% of the data before a bad sector crashed it out and now I can't even get it to clear the G-list again....Grrrr!!! I may be at the mercy of Ace Labs to come out with an update to support this model so I can build a software translator...

Re: 3.5" Toshiba's

July 21st, 2015, 2:16

The order of the 4 flash memories in the MCU's address space, from low to high, appears to be IC12, IC11, IC9, IC10.

It might sound far fetched, but I wonder if the three LE25U81AQE chips might contain those firmware modules that would normally be written to the SA. If so, then that's where you might find the G-list.

Re: 3.5" Toshiba's

July 21st, 2015, 9:27

I'm pretty sure the G-list is on the platters by the way it's clicking on startup. Was able to clear the G-list at first and get sector access (could hear it grinding away clearing it). But, now it won't do it again.

Re: 3.5" Toshiba's

July 21st, 2015, 13:55

fzabkar wrote:The order of the 4 flash memories in the MCU's address space, from low to high, appears to be IC12, IC11, IC9, IC10.

Oops, I think I reversed the order. I believe the correct order, from low to high, should be IC10, IC9, IC11, IC12.

Re: 3.5" Toshiba's

January 4th, 2017, 11:18

Hi all, my MD04 was damaged accidently by using an incorrect power module cable. A small black square boom...

As show in the picture, anyone could tell me what is this? Mark on it is "63AN 78", hope I can fix it. An Inductor I guess?

Thanks in advance.

Re: 3.5" Toshiba's

January 4th, 2017, 11:29

And one more question...

If I replace IC10 to another hdd with same model, can it work?

Re: 3.5" Toshiba's

January 23rd, 2017, 17:26

Did you check the TVS diodes? One or both will probably be shorted. This will tell us whether the damage was done via the +5V or +12V input or both.

As for the mystery component, it appears to have 4 pins, one of which is switched by the adjacent transistor (?). I'm guessing that the component is a power switch. It would help if you could identify the 3 pins with the heavier traces - Ground, +5V or +12V, Vout?

Re: 3.5" Toshiba's

January 25th, 2018, 4:21


The part which I thought was a 5V TVS diode (marking "72") appears to be an ordinary 20V, 1A Schottky barrier diode. Therefore, it provides no overvoltage protection. The "XB" part appears to be a 15V, 1W zener diode, not a TVS diode.

RB160M-20, ROHM, 20V, 1A, Schottky barrier diode, marking 72, SOD-123/1206:

http://docs-asia.electrocomponents.com/webdocs/13e4/0900766b813e45a3.pdf (RB160M-30, marking 73)

http://rohmfs.rohm.com/en/products/databook/datasheet-nrnd/discrete/diode/schottky_barrier/rb160m-40.pdf (RB160M-40, marking 74)

https://www.buerklin.com/medias/sys_master/download/download/h72/h2d/8891259879454/technical-data-sheet-rohm-semiconductor-rb160m-60tr-en-20160314.pdf (RB160M-60, marking 76)

KDZTF-15B, Rohm, 15V, 1W Zener diode, marking XB:

Re: 3.5" Toshiba's

January 25th, 2018, 4:38

The "small black square" looks like a power switch or maybe an LDO regulator. Its "control" pin is most likely an Enable input. This pin is driven by the digital transistor, which in turn would be switched by digital logic, possibly the MCU.

DTC123J, Rohm, NPN digital transistor, 50V, 100mA, marking E42:
isthiswhatthisis.JPG (107.44 KiB) Viewed 10575 times

Re: 3.5" Toshiba's

January 25th, 2018, 15:09

Thanks for the update !

Re: 3.5" Toshiba's

January 26th, 2018, 4:32

The mystery IC is a TPS22912C.

TPS22912C, Texas Instruments, Ultra-small, Low On Resistance Load Switch With Controlled Turn-on, Vin = 1.4V - 5.5V, 2A, 60mohm ON-resistance, marking 78:

More info in the following thread:

Re: 3.5" Toshiba's

January 27th, 2018, 4:23

data-medics wrote:I posted a picture here: https://www.data-medics.com/forum/downl ... &mode=view

Your picture is now corrupt. I could upload it here, if that's OK?

Re: 3.5" Toshiba's

August 15th, 2018, 20:23

Full sized photo:

Other ICs:

TPS27081ADDCR, Texas Instruments, PFET High Side Load Switch w/ Level Shift & Adj Slew Rate Control, 1.2V - 8V, 3A, marking AUA, DFN6:

BD91364BMUU, Rohm, 2.9V - 5.5V, 5A, Integrated MOSFET Buck Converter, QFN-20:

Re: 3.5" Toshiba's

November 23rd, 2019, 14:16

Hello everybody :D ,
I wanted to warm up this old thread, because I have a similiar problem with the same Toshiba model (MD04ACA400).

I mistakenly used a 19V laptop charger to power up my external hard drive. Now it doesn't power up, nor makes any noise or spins. Unfortunately I have only this HDD and not a working duplicate, where I could compare the measurements.

I measured the diodes D703 and D704 with the following results:

  • D703:
    Multimeter shows continuity by beeping (tested both directions). R = 0 ohm. Maybe it's shorted?
  • D704:
    Diode test shows 091 in one direction and 1255 in the other. Measurement with resistor mode (with setting 20k) shows R= 6.02 and 0.530

A picture of the PCB is attached for for completeness. I would really appreciate, if you have any hints/tips/solutions, what I can try to fix this.
If you need more information, just let me know!

Best regards,
MD04ACA400 .jpg
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