Repair Hitachi pcb

[rameez]

I need to repair pcb which is of a hitachi drive and i have attached the picture below can someone tell me what is the problem in most of the cases when there is no power in hdd . Like which of the components are bad .




Thanks .

[Shortscurcuits]

Rameez check your MSN I sent you the schematic.

[maxword5]

salam alekm

i thisnk best thing in this cas is tracing 5 and 12 volt to see where it disappear in the pcb

[rameez]

thanks for reply but tracing the voltage seems to be a very time taking process . Like in maxtor drives there are two points where u can measure the
3.3v and 5v if there is any problem with that u can change the component corresponding to it , is there any point on IBM like this .

[maxword5]

salam alekm

i need to know where these 2 points in maxtor

[Shortscurcuits]

Heres the main voltages on a working IC35L040AVER07-0. Seems to have same PCB. Try cold spray, or fingers to see if 90G2018 gets warm or hot, and check voltages with the pinout I PM'd you. If 90G gets warm for a few seconds, then goes cold it's probably the problem. You should feel Q1, Q2, & Q3 get warm but not hot. If they stay cold check the voltage at pins also.

[maxword5]

salam alekm

i want maxtor pcb main faults please

[rameez]

These are the two points :

[rameez]

if any one has any other useful info please share .

Thanks .

[maxword5]

salam alekm
and how to repair these errors in these points?

[pepe]

Hello,

first: the 5V test point shown on the picture is -5V in reality. Not that much of a difference

3.3V: if not present, probably the L7250E motor combo is damaged, but there is also a fusing resistor near R504 (on calypso III boards), this can be broken too, but mostly it is broken only after a power surge on the 5V line. Can be caused by the transistor (Q501) damage too, but I have never seen such case.
-5V: if not present, the L7250E or the FDFS2P102 (W503 on some boards) can be burnt. But be careful, if it is burnt there should be a cause for that, for example a preamp damage inside the HDA.

BTW I am always telling anybody who wants to touch a PCB should have at least some basic education of electronics, preferably an experienced technician or engineer...
Just to recognize the parts and figure out their function at least.

regards,
pepe

[avila]

Rameez check your MSN I sent you the schematic.

I'm working on the same problem like Rameez. I have a broken HDS722516VLAT80, where the electronic seams to be broken. Here the schematic would be usefull. This shematics will also be usefull, if I it is not the same type, so I can go one with the pionouts.

Thank's a lot for each help and effort.
AVILA

[Shortscurcuits]

Hi Avila I don't have the schematic for the IBM boards. If anyone has the datasheet for 90G2018 chip, I would appreciate it. I checked the Hitatchi site but it is no longer there for the partners program.