Quote:
1. As long as your board Sticker is 0A53047 and Main Controller Chip is 0A29626 and Board Number is 0A29531 ,our board is same as yours in hardware
Well i guess i can't use second hdd as donor
.tnx for help.
| HDD GURU FORUMS http://forum.hddguru.com/ |
|
| Replacing PCB on Hitachi HDT725025VLA380 http://forum.hddguru.com/viewtopic.php?f=26&t=39973 |
Page 1 of 1 |
| Author: | stefax2001 [ May 30th, 2020, 14:41 ] |
| Post subject: | Replacing PCB on Hitachi HDT725025VLA380 |
Hello,can you help me? I have 2 HDDs: First one is: Hitachi Model:HDT725025VLA380 P/N:0A33423 MLC:BA2367 Main controller IC:0A29626 PCB Label:
And second is: Hitachi Model:HDS721616PLA380 P/N:0A33932 MLC:BA2357 Main controller IC:0A29625 PCB Label:
First hdd pcb is fried and second hdd is full of bad sectors. Is it possible to replace pcb on first hdd with pcb from second hdd (I know i will have to replace 8-pin chip)? P.S. Sorry for my bad english. |
|
| Author: | fzabkar [ May 30th, 2020, 15:07 ] |
| Post subject: | Re: Replacing PCB on Hitachi HDT725025VLA380 |
https://www.hdd-parts.com/17110243.html |
|
| Author: | stefax2001 [ May 30th, 2020, 15:18 ] |
| Post subject: | Re: Replacing PCB on Hitachi HDT725025VLA380 |
Quote: 1. As long as your board Sticker is 0A53047 and Main Controller Chip is 0A29626 and Board Number is 0A29531 ,our board is same as yours in hardware Well i guess i can't use second hdd as donor .tnx for help. |
|
| Author: | fzabkar [ May 30th, 2020, 15:26 ] |
| Post subject: | Re: Replacing PCB on Hitachi HDT725025VLA380 |
What's wrong with the original PCB? |
|
| Author: | stefax2001 [ May 30th, 2020, 15:32 ] | ||
| Post subject: | Re: Replacing PCB on Hitachi HDT725025VLA380 | ||
fzabkar wrote: What's wrong with the original PCB?
|
|||
| Author: | fzabkar [ May 30th, 2020, 15:53 ] |
| Post subject: | Re: Replacing PCB on Hitachi HDT725025VLA380 |
That's the 5V TVS diode. It appears that your drive sustained an overvoltage on the 5V input. Hitachi drives aren't very well protected, so there is a risk that the preamp is damaged. Do you have a multimeter? Can you measure the resistance of the diode, D4, and the adjacent resistor, R5? TVS Diode FAQ: http://www.hddoracle.com/viewtopic.php?f=100&t=86 |
|
| Author: | stefax2001 [ May 30th, 2020, 16:31 ] |
| Post subject: | Re: Replacing PCB on Hitachi HDT725025VLA380 |
fzabkar wrote: That's the 5V TVS diode. It appears that your drive sustained an overvoltage on the 5V input. Hitachi drives aren't very well protected, so there is a risk that the preamp is damaged. Do you have a multimeter? Can you measure the resistance of the diode, D4, and the adjacent resistor, R5? TVS Diode FAQ: http://www.hddoracle.com/viewtopic.php?f=100&t=86 D4:0Ω R5:0Ω |
|
| Author: | fzabkar [ May 31st, 2020, 14:33 ] |
| Post subject: | Re: Replacing PCB on Hitachi HDT725025VLA380 |
Am I right in assuming that the drive now causes your PSU to shut down? If so, then remove D4 and your PCB will probably work again, albeit without protection on the 5V input. |
|
| Author: | stefax2001 [ May 31st, 2020, 19:16 ] |
| Post subject: | Re: Replacing PCB on Hitachi HDT725025VLA380 |
fzabkar wrote: Am I right in assuming that the drive now causes your PSU to shut down? If so, then remove D4 and your PCB will probably work again, albeit without protection on the 5V input. Yes PSU shuts down when i connect contacts of broken diode. I checked resistance of diode D4 and resistor R5 again (with different multimer) and got -1018Ω for D4 and -1658Ω for R5??? A bit dumb question,but did i make some mistake or what? Should i still remove D4? |
|
| Author: | fzabkar [ May 31st, 2020, 20:42 ] |
| Post subject: | Re: Replacing PCB on Hitachi HDT725025VLA380 |
stefax2001 wrote: Yes PSU shuts down when i connect contacts of broken diode. What do you mean by this? I wanted to know whether the PSU shut down when the broken HDD was originally connected to it. You didn't say how the drive came to be damaged. |
|
| Author: | stefax2001 [ June 1st, 2020, 4:31 ] |
| Post subject: | Re: Replacing PCB on Hitachi HDT725025VLA380 |
fzabkar wrote: What do you mean by this? I wanted to know whether the PSU shut down when the broken HDD was originally connected to it. You didn't say how the drive came to be damaged. What i meant when i said: stefax2001 wrote: Yes PSU shuts down when i connect contacts of broken diode. Was this: Attachment:
File comment: Top plastic part of D4 is melted. IMG_20200601_095236.jpg [ 1.84 MiB | Viewed 32251 times ] Attachment: IMG_20200601_095243.jpg [ 2.82 MiB | Viewed 32251 times ] Attachment: IMG_20200601_095231.jpg [ 2.95 MiB | Viewed 32251 times ] |
|
| Author: | fzabkar [ June 1st, 2020, 19:53 ] |
| Post subject: | Re: Replacing PCB on Hitachi HDT725025VLA380 |
Your statement implies that you connected a PSU to the diode rather than to the HDD, in which case it makes no sense. Or do you mean that you "reassembled" the broken diode and then reconnected the HDD to the PSU??? Whatever you did, your latest measurements indicate that the diode has gone open circuit, and resistor R5 is now also open. IIUC, this resistor is in series with the 5V supply to the preamp, so there is a real possibility that your preamp is shorted. You can test for this possibility by measuring the resistance between ground and R5, and then comparing the result with the PCB on and off the drive. It goes without saying that you should check the 5V and 12V outputs of your PSU. Obviously there was an overvoltage on the 5V output, so either the PSU is faulty, or you have used the wrong modular cable. |
|
| Author: | stefax2001 [ June 2nd, 2020, 10:43 ] |
| Post subject: | Re: Replacing PCB on Hitachi HDT725025VLA380 |
fzabkar wrote: Your statement implies that you connected a PSU to the diode rather than to the HDD, in which case it makes no sense. Or do you mean that you "reassembled" the broken diode and then reconnected the HDD to the PSU??? I normally connected PSU to HDD with molex and then "reassembled" diode. fzabkar wrote: Whatever you did, your latest measurements indicate that the diode has gone open circuit, and resistor R5 is now also open. IIUC, this resistor is in series with the 5V supply to the preamp, so there is a real possibility that your preamp is shorted. You can test for this possibility by measuring the resistance between ground and R5, and then comparing the result with the PCB on and off the drive. When you said "PCB on and off the drive" you mean literally disassembling PCB from HDD? Anyway i got -1003Ω for both measurements on and off. fzabkar wrote: It goes without saying that you should check the 5V and 12V outputs of your PSU. Obviously there was an overvoltage on the 5V output, so either the PSU is faulty, or you have used the wrong modular cable. I already checked PSU and got: 5.27v and 11.70v |
|
| Author: | fzabkar [ June 2nd, 2020, 15:33 ] | ||
| Post subject: | Re: Replacing PCB on Hitachi HDT725025VLA380 | ||
The resistor should have a value of 0.47 ohms. I would measure the resistance to ground at the preamp end, if you haven't done so already.
|
|||
| Author: | stefax2001 [ June 2nd, 2020, 18:59 ] | ||
| Post subject: | Re: Replacing PCB on Hitachi HDT725025VLA380 | ||
fzabkar wrote: The resistor should have a value of 0.47 ohms. I would measure the resistance to ground at the preamp end, if you haven't done so already. I got this.
|
|||
| Author: | fzabkar [ June 2nd, 2020, 19:44 ] |
| Post subject: | Re: Replacing PCB on Hitachi HDT725025VLA380 |
You can try a donor PCB, but be prepared for a bad preamp, in which case you may be wasting your money. |
|
| Author: | stefax2001 [ June 2nd, 2020, 20:53 ] |
| Post subject: | Re: Replacing PCB on Hitachi HDT725025VLA380 |
So donor PCB should be compatible? stefax2001 wrote: This HDD (with bad PCB):
Hitachi Model:HDT725025VLA380 P/N:0A33423 MLC:BA2367 Main controller IC:0A29626 PCB Label:
Donor HDD: Hitachi Model:HDS721616PLA380 P/N:0A33932 MLC:BA2357 Main controller IC:0A29625 PCB Label:
|
|
| Author: | fzabkar [ June 2nd, 2020, 21:08 ] |
| Post subject: | Re: Replacing PCB on Hitachi HDT725025VLA380 |
They have different MCUs (0A29625 vs 0A29626). I'm not a DR pro, but I would think that the PCBs would be incompatible. |
|
| Author: | stefax2001 [ June 3rd, 2020, 8:23 ] |
| Post subject: | Re: Replacing PCB on Hitachi HDT725025VLA380 |
Ok,thank you. |
|
| Page 1 of 1 | All times are UTC - 5 hours [ DST ] |
| Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/ |
|