All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 72 posts ]  Go to page Previous  1, 2, 3, 4  Next
Author Message
 Post subject: Re: Hitachi HDD data recovery
PostPosted: June 9th, 2021, 18:17 
Offline
User avatar

Joined: September 8th, 2009, 18:21
Posts: 15461
Location: Australia
Tomset wrote:
there are boards on the PLA380
PCB:
0A29374
0A29375

I see 0A29582 on both PCBs???

_________________
A backup a day keeps DR away.


Top
 Profile  
 
 Post subject: Re: Hitachi HDD data recovery
PostPosted: June 9th, 2021, 18:40 
Offline

Joined: October 21st, 2007, 8:48
Posts: 1631
@ op
You are from Syria?
Where are you living now?
If you living in Egypt now, I can help you for free.
Good luck


Top
 Profile  
 
 Post subject: Re: Hitachi HDD data recovery
PostPosted: June 9th, 2021, 18:46 
Offline
User avatar

Joined: September 8th, 2009, 18:21
Posts: 15461
Location: Australia
fzabkar wrote:
Tomset wrote:
there are boards on the PLA380
PCB:
0A29374
0A29375

I see 0A29582 on both PCBs???

0A29374/0A29375 appear to be motor controller ICs, not PCB part numbers.

_________________
A backup a day keeps DR away.


Top
 Profile  
 
 Post subject: Re: Hitachi HDD data recovery
PostPosted: June 9th, 2021, 18:51 
Offline

Joined: September 29th, 2005, 4:10
Posts: 402
Location: Moscow
fzabkar,
Yes, sorry, I looked in the wrong column.
F 0A29582 01
F 0A29526 01

I stop doing DR. Losses and age. There is no point in continuing to work. As soon as I check all the donors, I will lay out the tables in the sale of large lots.
You'll need them, but I won't.


Top
 Profile  
 
 Post subject: Re: Hitachi HDD data recovery
PostPosted: June 10th, 2021, 0:58 
Offline

Joined: June 4th, 2021, 3:17
Posts: 34
Location: syria
unknown wrote:
@ op
You are from Syria?
Where are you living now?
If you living in Egypt now, I can help you for free.
Good luck


I live in syria damascus
thank you very much for your offer


Top
 Profile  
 
 Post subject: Re: Hitachi HDD data recovery
PostPosted: June 10th, 2021, 16:41 
Offline

Joined: June 4th, 2021, 3:17
Posts: 34
Location: syria
fzabkar,

on the both patientand donor PCB
v1 = 1.74
v2 = 1.74
v3 = 1.74
V+ = +5
V- = -5

Measurement for resistance for V+ and V- is between ground and the V (V+ or V-)
correct?


Top
 Profile  
 
 Post subject: Re: Hitachi HDD data recovery
PostPosted: June 10th, 2021, 17:04 
Offline
User avatar

Joined: September 8th, 2009, 18:21
Posts: 15461
Location: Australia
hddr wrote:
Measurement for resistance for V+ and V- is between ground and the V (V+ or V-)
correct?

Yes.

As for your voltages, I would have expected to see +3.3V somewhere. :?

_________________
A backup a day keeps DR away.


Top
 Profile  
 
 Post subject: Re: Hitachi HDD data recovery
PostPosted: June 10th, 2021, 17:42 
Offline
User avatar

Joined: September 8th, 2009, 18:21
Posts: 15461
Location: Australia
fzabkar wrote:
As for your voltages, I would have expected to see +3.3V somewhere. :?

I think you may be using the wrong ground reference. When measuring V1, V2 and V3, your black probe should be on ground, eg a screw hole.

_________________
A backup a day keeps DR away.


Top
 Profile  
 
 Post subject: Re: Hitachi HDD data recovery
PostPosted: June 10th, 2021, 17:43 
Offline

Joined: June 4th, 2021, 3:17
Posts: 34
Location: syria
in the two PCBs resistance are:
R5 = 20

off drive
V+= 1900
V- = 110

on drive
V+ = 1500
V- = 20


Top
 Profile  
 
 Post subject: Re: Hitachi HDD data recovery
PostPosted: June 10th, 2021, 17:56 
Offline
User avatar

Joined: September 8th, 2009, 18:21
Posts: 15461
Location: Australia
hddr wrote:
in the two PCBs resistance are:
R5 = 20

off drive
V+= 1900
V- = 110

on drive
V+ = 1500
V- = 20

The resistance of R5 should be 0.47 ohms. :?

Resistance should be measured between the ends of the resistor, and it should be done with power switched off.

The resistances at V+ and V- should be measured between ground and each test point.

If you touch the two probes together, do you measure 0.0 ohms resistance?

_________________
A backup a day keeps DR away.


Top
 Profile  
 
 Post subject: Re: Hitachi HDD data recovery
PostPosted: June 10th, 2021, 18:08 
Offline

Joined: June 4th, 2021, 3:17
Posts: 34
Location: syria
the problem is with the millimeter I used, Its not precise
the reading did not changed after connecting the two prop outside the PCB
:(


Top
 Profile  
 
 Post subject: Re: Hitachi HDD data recovery
PostPosted: June 10th, 2021, 18:16 
Offline
User avatar

Joined: September 8th, 2009, 18:21
Posts: 15461
Location: Australia
If your multimeter is showing 20 ohms when the two probes are touching each other, then this would imply that the V- supply, which is also measuring 20 ohms, is shorted inside your preamp. :-(

You can check whether your probes are OK by removing one probe and then measuring the resistance of the remaining probe by inserting the probe tip into the multimeter. Do this for each probe.

You should also rotate the selector knob backwards and forwards to disturb any contact oxidisation.

_________________
A backup a day keeps DR away.


Top
 Profile  
 
 Post subject: Re: Hitachi HDD data recovery
PostPosted: June 10th, 2021, 18:20 
Offline

Joined: June 4th, 2021, 3:17
Posts: 34
Location: syria
fzabkar wrote:
If your multimeter is showing 20 ohms when the two probes are touching each other, then this would imply that the V- supply, which is also measuring 20 ohms, is shorted inside your preamp. :-(


and that mean it is hopeless case?


Top
 Profile  
 
 Post subject: Re: Hitachi HDD data recovery
PostPosted: June 10th, 2021, 18:31 
Offline
User avatar

Joined: September 8th, 2009, 18:21
Posts: 15461
Location: Australia
Yes, it would appear that your drive is not a DIY candidate, but an accurate measurement would give me more confidence in my assessment.

_________________
A backup a day keeps DR away.


Top
 Profile  
 
 Post subject: Re: Hitachi HDD data recovery
PostPosted: June 10th, 2021, 18:35 
Offline

Joined: June 4th, 2021, 3:17
Posts: 34
Location: syria
I will arrange to get these measurement in better multimeter


Top
 Profile  
 
 Post subject: Re: Hitachi HDD data recovery
PostPosted: June 11th, 2021, 8:01 
Offline

Joined: June 4th, 2021, 3:17
Posts: 34
Location: syria
fzabkar,

I do the following test:

Put the donor PCB on the donor drive and measure the V- and it was near 80 ohm
I assume that mean confirming the V- shorted inside the patient preamp as you mention before.


Top
 Profile  
 
 Post subject: Re: Hitachi HDD data recovery
PostPosted: June 11th, 2021, 9:02 
Offline

Joined: September 29th, 2005, 4:10
Posts: 402
Location: Moscow
If there was a bad preamp, it would start the motor while isolating the preamp.
Return the NVRAM to the new board, and check if you have already killed it.


Top
 Profile  
 
 Post subject: Re: Hitachi HDD data recovery
PostPosted: June 11th, 2021, 11:15 
Offline

Joined: June 4th, 2021, 3:17
Posts: 34
Location: syria
Tomset wrote:
If there was a bad preamp, it would start the motor while isolating the preamp.
Return the NVRAM to the new board, and check if you have already killed it.

so it may be more than one problem in this drive


Top
 Profile  
 
 Post subject: Re: Hitachi HDD data recovery
PostPosted: June 12th, 2021, 1:25 
Offline

Joined: June 4th, 2021, 3:17
Posts: 34
Location: syria
fzabkar,

I do the following test:

Put the donor PCB on the donor drive and measure the V- and it was near 80 ohm
I assume that mean confirming the V- shorted inside the patient preamp as you mention before.

Please confirm.


Top
 Profile  
 
 Post subject: Re: Hitachi HDD data recovery
PostPosted: June 12th, 2021, 2:27 
Offline
User avatar

Joined: September 8th, 2009, 18:21
Posts: 15461
Location: Australia
Are you still using the "bad" multimeter?

_________________
A backup a day keeps DR away.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 72 posts ]  Go to page Previous  1, 2, 3, 4  Next

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 54 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group