Barracuda XT, Barracuda, Barracuda Green, DiamondMax and other desktop SATA and IDE drives

[ravi6662]

hello all... im a computer tech since 1983

and also electronics in the late 1970..

having a seagate drive.

wiht a board PCB 100466725

REV A DLAJ-4 

does anyone have a component layout of it

with the parts list..

its for a ST3500320AS drive

PN : 9BX154-303

thanks

ravi

[fzabkar]

I don't believe Seagate releases any circuit diagrams for their hard drives. As for a parts list, many of the ASICs appear to be proprietary and specially made for Seagate.

You can get an idea of the function of each part from this article:

http://hddscan.com/doc/HDD_from_inside.html

If you like, I can help you track down datasheets for any parts that interest you, assuming they are available. I'd need you to upload a close-up photo, or post the part numbers on the chips, or both.

BTW, I've been a computer tech since 1981. :-)

[ravi6662]

yeah. wow. thanks.. actually my first computer was a timex sinclair ZX81.. and i still have it.

thanks for ur suggestion. i do have pictures of it.. ..

i can see the ## on the chip beside it.. not that hard with my macro lens.

but the main power bridge rectifier (i suppose) is burnt..  looks like a  zener diode.

did electronics back in 1979.. had my first multitester and soldering iron when i was 15yrs old.. lol

[Edited: Removed personal information per the community rules and regulations.]

Message Edited by BradC on 10-11-2009 09:55 AM

[ravi6662]

ok.. narrowed it down to the TVS diodes..

now where do i get such a thing.

i can see the part number of the one next to it....

can i salvage ANY other TVS diodes from another drive?

---

quote - Another protection device called Transient Voltage Suppression diode or TVS diode. It protects PCB from power surges from external power supply. When TVS diode detects power surge it fries itself and creates short circuit between power connector and ground. There are two TVS diodes on this PCB for 5V and 12V protection.

---

is this  a standard component. .? i think the 12v diode is blow.

i have   a picture.. how do i put it on here??\\

thanks for that url fzabkar..

and i was thinking www.deadharddrive.com was cool.. lol

cant put image from local drive. ? i can host it on my website..  right?

[fzabkar]

You can upload the photo to your own web space or to an image hosting site. Then link to it in your next message.

The TVS diodes connect across the +12V and +5V rails. It appears that one of them has suffered a sustained overvoltage.

Here is a pinout of the SATA power connector:

http://pinouts.ru/Power/sata-power_pinout.shtml

If you can trust your PSU, then you can desolder or snip out the faulty TVS diode. The hard drive should work quite happily without it, albeit without protection on that supply rail.

You can use a TVS from another HD as a replacement.

Alternatively you can get an SMAJ5.0A (400W) 5V unidirectional TVS or an SMBJ12A (600W) unidirectional TVS:

http://www.datasheetarchive.com/search.php?t=0&q=SMAJ&manystr=&sub.x=24&sub.y=12

http://www.datasheetarchive.com/search.php?t=0&q=SMBJ&manystr=&sub.x=24&sub.y=12

If there is a zero-ohm link near the diode, test it for continuity.