HDT722525DLAT80 NV-RAM ERROR.

[DRUG]

Can anyone provide me with the NV-RAM file for this disk ?

USAG module also fails to read.

Attachments

[drHDD]

How we should find out which version of firmware you have in this drive?

[pcimage]

NV-RAM is unlikely failure

[DRUG]

I'm only going to be at office on monday, however I know its not arm type, the disk can't be ID'ed. When i try to scan I cant access any sector at all. However after this post i noticed C13 was missing from PCB at all. I'll get to you as soon as possible. All the modules I can read are 00. What kind of issue might this be?

[DRUG]

I'm only going to be at office on monday, however I know its not arm type, the disk can't be ID'ed. When i try to scan I cant access any sector at all. However after this post i noticed C13 was missing from PCB at all. I'll get to you as soon as possible. All the modules I can read are 00. What kind of issue might this be?

What do you mean that all modules that you can read are 00 ? They are empty (no content at all) even if the MRT Tool states that it read sucessfuly ? Can you read NVRam and ROM ?

So i got back today, only to find out that:

All modules fail to read, ATA1 fails to initialize the device.

Can't load Teachkey, can't load NV-RAM, nothing.

[DRUG]

Were you able to read NVRAM to start with ?
Does your pcb have external ROM as well ?

No, I couldn't.

Yes it does.

Please pay attention to C33, it looks damaged.

Attachments

[data-medics]

Doesn't look damaged, it looks missing.

[jermy]

so do it the old fashioned way... transfer the ROM chip or read the ROM with an external programmer
and like pcimage said

NV-RAM is unlikely failure

Last edited by jermy on December 7th, 2015, 14:53, edited 1 time in total.

[dick]

I have the same model drive here and the missing C33 capacitor is the same physical size as C11 but on my drive it is a darker brown colour. C11 is lighter brown colour. That may or may not be important.

[fzabkar]

Measure the voltage between the pins of C33. If it is 18V or so, then it is the boost capacitor for the VCM servo.

FWIW, the L7250 SMOOTH datasheet specifies a 330nF VBOOST capacitor. I don't know whether the smaller capacitor to the left of C33 can cope on its own. If not, then I would expect instability in the servo.

[fzabkar]

The headstack would probably still move, but it may not lock onto the track reliably. The boost voltage is required for controlling the drive to the high-side MOSFETs. The drive to the low-side MOSFETs would still be OK. I'm not completely certain, though.

In any case, I could be wrong about the function of C33. It may in fact be bypassing the +5V or +12V supply to the motor controller, in which case its absence would not be super critical. Perhaps dick could confirm the voltage on his PCB.

[dick]

Happy to oblige.
So it measures 11.89v across the capacitor.
12v rail direct from the psu reads 11.94v

[fzabkar]

It looks like C33 may be the bypass capacitor for the low frequency noise on the +12V supply. The smaller capacitor would then be filtering the high frequency noise. A continuity test between the +12V terminal of the capacitor and the +12V input to the PCB would confirm this beyond doubt.

[dick]

It looks like C33 may be the bypass capacitor for the low frequency noise on the +12V supply. The smaller capacitor would then be filtering the high frequency noise. A continuity test between the +12V terminal of the capacitor and the +12V input to the PCB would confirm this beyond doubt.

As expected NO noticeable resistance was measured.

[DRUG]

Well, I'll get a donor for some rom swap and hope that servo is stable.