PCB for WD2500JB


Hallo here in forums,

i have a HD here that was in a  external case and where somebody had attached the wrong adapter…it got to much Volts and the PCB burned away.

i hope the internat magnetarm-elektronic is not damadged, because the pins, that lead to the elektronic (not to the rotating motor) are a little bit brouwn.

i think ive a good chance, that i could save the data it was onto if i get a matching PCB. but then searching for that i had to realize, that WD changed the hardwaredesign very often in a short time of a few month.

can someone help me to find out, if some models i found of ebay possible has the exact PCB on it. and perhaps give me a little prognose, how good is the chance i get it to run again ?

these is the data of my drive:

MDL: WD2500JB-00REA0

DATE: 19 NOV 2006


short question: is “DCM” the serial ?

i already had tested a drive from 24 FEB 2007 without sucsess…the drive rotates and sounds normal but it isnt recoognized correctly (the motor is not damaged by overvoltage. thats a good sign. i think the overvoltage made shortcut some diodes or some parts that damaged the PCB but prevented the inside elektronic from being damaged.)

anyway it wasnt the right PCB.

i first thought it is enough to look for the number on the PCB (2060-701292-002 REV A) but then i had to realized, that this only means the board design, not the controllers being used.

the controllers being used in this revision are:



ETRONTECH EM638165TS-66 K413208RLJ7721H


SMOOTH L6283 1.3

my question is if the controller of a drive from “19 DEC 2006” is the same ?

WD so often changed the PCB, that im not sure…their is 1 month between the drives.

perhaps someone have that drive and can sell it ?

the data on it isnt soo important, but i try to safe it for a girlfriend and im sure she would be happy if i manage this.

i also thought about changing all the smd-parts on board and trying my luck by replacing the diodes,resistors,controllers and so on…but im not sure if itz worth.

ps.: sry if ive bad english (from germany)

thx 4 every help


This forum thread explains DCM (Drive Configuration Matrix):

The ETRONTECH part is an SDRAM, not a controller.

Your board probably has a shorted TVS diode near the power connector. If you can upload a detailed photo to a file sharing service, one of us will be able to help you with a possible DIY fix.

If you replace the PCB, you will also need to transfer the ROM contents from patient to donor. If the ROM is internal to the Marvell MCU (88I6540LFH1), then this will require specialist data recovery services.

These articles should help you identify the various components:

HDD from inside Main parts:

WD Pc easy Faultdiagnostic troubleshooting must try it …


Hey :slight_smile:

THX 4 the help…i see it coming i will manage this because of this help here…

i made pictures:





as you suspected it was the diode…because as i tried to determin witch part is getting hot (with my multimeter)…the part detached from itself, because it was so hot, that the solder of the diode melt.

how it shown on the pictures the hole board was so hot on a few points. the color changed at severas points…also at points far away from the TVS diode. on a healthy PCB all points are bright silver. i dont think it is done by just replacing the diode but i can give it a try.

i also already purchased a harddrive from ebay:


it is from 19 DEC 2006. myone is from 19 NOV 2006. after connecting me to the WD-telephon-support we could find out by the serialnumbers of the harddrives, that WD have a different firmware on it. but their is a chance, that it will work, because the hardwaredesign seems to be the same.

if it will be nessasary to transfair the ROM-contend i dont know what would be easier. i think the best way is to just replace the chip itself, if it still works. then i have to improve my smd-equipment.

i already had a case in past there i just replaced the PCB of a HD and it worked without transfairing the roms-contend. whats the deal with that ? is it, the table of the error-sectors ? i dont know how i can say it in english…ill try:

if i just change PCBs without transfairing the data their will be wrong sectors for the errorlist…but their is a good chance, that i anyway could backup very important files on the HD (even if it is a not so professional way). because their are some DOCs on a 250GB drive and the chance is good to rescue many files, because the errorlist of the new PCB dont touches many litte files on the harddrive ?  by that way i could make a prebackup of al files possible to rescue with the PCB i get from ebay, before starting with soldering-actions and trieing to change controllers and stuff like that.

just wanted to say by the way, that i postet all chips because i thought it is better for you to find out wich hardwarerevision it is…im not totally unexperienced in working with chips.

ps.: these are very cool sides u posted THX :slight_smile:


The part marked “BUF” at location D6 is an SMBJ13A Transient Voltage Suppression diode. It has a working voltage of 13V and a breakdown voltage of around 15V.


You can substitute D6 with a unidirectional 12V TVS diode, eg an SMBJ12A from Farnell, Mouser, Digikey. Alternatively, if your PSU is OK, the drive will work without the diode, but it will no longer have overvoltage protection on the 12V rail.

You should also confirm that the “000” resistor at R82 (beside D6) is not open. This zero ohm resistor behaves like a fuse. If open, replace it with a piece of wire, or a 2A picofuse or smt fuse.

Littelfuse Surface Mount Fuses, N = 2A, S = 4A:

The serial EEPROM is the 8-pin chip at U12 (25P0??). You should be able to find its datasheet in my scratchpad style notes:


The EEPROM stores unique, drive specific calibration data. Identical drives manufactured in the same factory on the same day will have different ROM contents. In particular, there are “adaptive” data for each head.

The following article explains why drives have adaptive data.

HDD from inside: Tracks and Zones. How hard it can be?

Essentially the reason is that no two heads are physically identical. HD manufacturers try to fit as much data as possible onto each platter. To do this, they take advantage of any head that performs better than the average.

For example, some heads will have a better frequency response than others, which means that you can cram more bits on each track. This technique is called Variable Bits Per Inch (VBPI).

Giant magnetorestive (GMR) heads use a separate element for writing and another for reading. The separation between these two components varies from head to head. Once again manufacturers optimise data density by implementing Variable Tracks Per Inch (VTPI).

Each HD therefore needs to be calibrated to account for VBPI and VTPI, otherwise the drive doesn’t know where to find the tracks, or the data within the track. When a drive powers up, it needs to retrieve the bulk of its firmware from a reserved area (System Area) on the platters. If it can’t read these data, then it clicks. This is what usually happens after you swap a board without transferring the calibration information.

To elaborate on the question of firmware, in times past, the firmware was stored wholly within an EPROM chip. Nowadays the bootstrap firmware is masked into the MCU. Additional firmware and adaptive data are stored in the serial EEPROM chip. Sometimes this chip is internal to the MCU. When the MCU powers up, it reads the EEPROM code and data, copies them to SDRAM, and then transfers control to the RAM code. This code then uses the adaptive data to locate the bulk of the firmware on the platters. The firmware includes the ATA command module, SMART code, logical-to-physical sector translator, etc. The SMART data and bad block maps (P-list and G-list) are also stored on the platters, not in EEPROM.

See the following article by “aimtrading”:

About firmware, SA, etc:

As for your concerns regarding “hot spots”, I would use a soft white pencil eraser to gently shine up the 20-pin preamp pads at J1 near the TVS diodes. The hotspots are in fact corrosion. Unfortunately this is a problem that afflicts current HDs. Both WD and Seagate appear to be affected. It is the result of materials changes forced upon manufacturers by RoHS. Lead free solder is BAD news.

See this thread for more corrosion examples:


thx for that real good explanation…after all heard i think ill give a try to fix it by replacing the parts. i will run to my elektronics-trader in town and look for a diode. but i think i have to order a smd-diode…what to you think about the idea, that i replace the diode by an not-smd form of an diode with the same specs ? there is enough room to manage this with  a few cables. this should work just to back the data. i just ask, because if i order that on part by internet i pay 5€ postal-money.

by the way, both 000-resistors are ok


You could use a leaded diode in the P6KE series:


The P6KE15 has a stand-off voltage rating of 12.1V, and a breakdown voltage of 13.5/16.5 min/max.

You could solder it directly across the +12V and Ground pins on the PCB side of the SATA power connector:


ahhh second now i realize !!!  the PCB will work WITHOUT the diode. i will control that their is no overvoltage on the 12V-rail i use and give it a try.  **bleep**, if that works i ordered a harddrive for 100$ from USA that wasnt nessecarry



i like overvoltage diodes…who has invented them ? i love him !

thx for any help…anyway on the way by “solving” this problem i learned much new about harddrives.

the journey is itz own reward


I have the same problem that revnu did - 250GB drive from an external enclosure that simply stopped (no clicking sound).

MDL: WD2500JB-00REA0

DATE: 16 NOV 2006


I tried putting it in as a second drive within my PC case.  BIOS does not see the drive, and it does not spin up, but the board gets very warm to the touch.  I felt like I had little to lose, so I also removed the BUF diode at B6 - same result.  I’ve read conflicting information on whether I could just replace the whole PCB without tranferring the firmware.

Do I have any options at this point?


Normally you would need to transfer the EEPROM contents. You could be lucky, though, and the two drives may have similar “adaptive” data.


I also have a WD2500JB-00READ that is not spinning and the PCB board gets hot when plugged in. I have tried following the instructions here to remove the D6 diode but I am unable to locate it on my PCB board and OP pictures are no longer available.

I am seeing that parts near Q6 are ‘fried’ looking. Could this be the diode I need to take out?


Here is a link to the picture of my board.


“PCB Board”)


Your SMOOTH motor controller chip appears to have failed. Assuming the spindle motor is OK, your most expedient solution is to replace the board and transfer the 8-pin serial flash memory chip at U12 from patient to donor. If you have a multimeter, you should test the motor windings. There are three phases plus a common terminal. The phase-to-common resistance should be of the order of 3 ohms. Phase-to-phase should be 6 ohms or thereabouts.


Do you have any suggestions on where to get a new PCB board? I have been googling for hours.


I think this may be your board:

The supplier offers a board, including firmware transfer service, for US$70.


Every combination of the 4 contacts on the motor come back at 0 OHM. Does this mean my windings are bad?


It appears that you may have set your meter to one of the higher ranges. Use the lowest (200 ohms ?) range.


My meter is a cheap one and only has one setting for OHM and the range goes from 0-1000 with 5 being in the center. If my windings were bad what would I expect to see Ohms wise?


Here is a typical analog multimeter:

It has 4 resistance ranges – X1, X10, X1K, and X10K.

You would select the X1 range and zero the reading with the Ohm Adjust knob while touching the probe tips together.

The dial will then display the reading directly in ohms.

To confirm that you are doing things correctly, you can measure the resistances of your toaster or electric jug, or any other high wattage appliance. Disconnect them from the mains (of course) and turn them on while measuring the resistance between the active and neutral pins in the plug.

My 240VAC, 750W toaster measures 77 ohms, and my 240VAC, 2200W electric jug measures 27 ohms.

The formula is …

resistance = voltage squared / power

So (240^2) / 750 = 76.8 and (240^2) / 2200 = 26.2