been studying the posts and learned a ton but I have a few
questions before I go soldering my drives PCB.
I have a seagate 7200.12 model ST7350528as, I like this model
number, it fits seagate for totally screwing their customers and
not even getting it completely fixed in the next series.
The drive has the firmware bug. Yes, I did part of the procedure
for 7200.11 drives and then changed what other 7200.12 users
I had to try a couple of times before it saved everything and
Problem is the drive won't spin up. I read another post where they
mentioned that since the board isn't fully connected to the drive
there is excess electricity flying around. I think with how many
times I tried to do this I shorted something or I pushed it to the
limit. I didn't drop any screws on the board or anything like
Now, after finding tons of stuff on the net, I am trying to test
the tvs diodes.
I am uploading a picture of my board. It has two shock sensors.
Can you test those?
Here are my results from testing the tvs diodes, the ones with the
red arrow under them. I used two digital voltmeters and one analog
volt meter. I looked on the board but could not tell which side
was the anode or cathode. I will list the results as R(red) lead
to the left side and B(black) lead to the right side of the diode.
B R would be when I switch the leads.
Digital Meter (both digital meters had similar results)
TVS 1 (diode setting) TVS 2
R-B 448 R-B 709
B-R pops up to 1400 then B-R 1 (a few times
goes straight to 1. it would pop to
1800 then go to 1)
Annalog Meter (this is where I get confused bec it's backwards and
I don't know the scale. I did zero the meter.
I have pics drawn but can't duplicate them so I will just give the
numbers and describe the position. If I get this right 0 on this
meter is to the right and the numbers get bigger as it moves to the
TVS 1 @ x10 TVS 2
R-B needle moved up a R-B nada, didn't move
little around 500
B-R moved to four B-R moved to 9
TVS 1 @ x1k TVS 2
R-B shoots up to 10 R-B goes to 10 then drops to
then goes to 20 100
B-R moves to 3 stays B-R goes to 6 and stays
Digial Meter @ 200ohms
TVS 1 TVS 2
R-B 462 pops up then 1 R-B 960 pops up then goes to 1
B-R Stays at 1 B-R moves to 6 and stays
Can someone tell me if either of these are bad? If not what else
can I check. Thanks in advance for your assistance.