Question: EMI Shielding for IDE cables

• Previous message: blue: "Re: Help reading capacitor code values"
• Next in thread: tempus fugit: "Re: Question: EMI Shielding for IDE cables"
• Reply: tempus fugit: "Re: Question: EMI Shielding for IDE cables"
• Reply: Kevin Kilzer: "Re: Question: EMI Shielding for IDE cables"
• Messages sorted by: [ date ] [ thread ]

Date: Thu, 19 Aug 2004 02:41:40 GMT

(Long story)
I am having problems with hard drive data corruption.
I have recently rebuilt some of my computers in rackmount casings. After
running them for a few weeks, I noticed that all of my files were becoming
corrupted. I have 4 x 160GB + 4 x 120GB hard drives where this is becoming a
problem. 2 of the drives lost their partition tables and became completely
useless.
I made valiant efforts to recover and preserve my data, but I have basically
given up.

After much investigation, I suspect the cause for these problems to be
related to my IDE cables.
1. With the chassis layout, the power supply is located at the front of the
case, leaving an AC power cable running directly under the hard drive bays
and the ide cables.
2. The rack itself houses 6 computers, 2 UPS, 2 power bars, and about 10-15
other devices (modems, switches, etc), so I expect that there is quite a bit
of interference here.
3. I am using flat ribbon 24" and 36" IDE cables, because shorter cables
will not reach from the drive bays to the ide controller connectors.
4. All drives are running ATA100

When doing data recovery, I removed the drives from the cages and ran short,
<18" ribbon cables. This seemed to greatly reduce the incidence of new data
corruption.

I have recovered whatever I could from the drives. They are now all freshly
formatted and repartitioned. Because of the problems I have had, I am afraid
to use them for anything.

I truly do believe that the IDE cables are my problem. I ordered a bunch of
rounded 36" ide cables, but when I got them, I realized they have no
shielding at all (I thought the point of rounding a cable was to put a
shielding around it!).

I expect that shielding these cables may help fix my problems. I am looking
for any advice on doing this. I initially thought I'd just get some aluminum
muffler tape from the auto parts store, and wrap the cables, but I'm not too
sure.
- Do I need to put a ground wire onto the shield? I think it would make
sense to have a drain on one end of the shield and attach it to the chassis
- Should I put one of those ferrite clamp shields on the ide cables?
- Should I put one of those ferrite clamp shields on the internal AC power
cable?

I also think it would be smart to wrap any shielding in an insulating
material, like electrical tape or something. But when electrical tape heats
up, the adhesive makes everything gooey. I don't know if I can fit heat
shrink tubing over the connectors. Any other ideas?

Thanks for making it to the end of this long email!
Keith
creekchubbAThotmailDOTcom (replace AT with @, and DOT with .)

• Previous message: blue: "Re: Help reading capacitor code values"
• Next in thread: tempus fugit: "Re: Question: EMI Shielding for IDE cables"
• Reply: tempus fugit: "Re: Question: EMI Shielding for IDE cables"
• Reply: Kevin Kilzer: "Re: Question: EMI Shielding for IDE cables"
• Messages sorted by: [ date ] [ thread ]