report - vibration test

7/27/2019 Report - Vibration Test

1/26

Vibration Test Report:

Copyright Dedicated Computing, 2004

NOTICE TO PERSONS RECEIVING THIS

DOCUMENT AND/OR TECHNICAL INFORMATION

Dedicated Computing claims proprietary rights to the material disclosed hereon. This drawing and/or technical information is issued inconfidence for engineering information only and may not be reproduced or used to manufacture anything shown or referred to hereon withoutdirect written permission from Dedicated Computing to the user. This drawing and/or technical information is the property of Dedicated

Computing and is loaned for mutual assistance, to be returned when its purpose has been served.

THIS DOCUMENT AND/OR TECHNICAL INFORMATION IS THE

PROPERTY OF DEDICATED COMPUTING


2/26

Date Originated: 4/12/04Title Vibration Test Report:CustomerCart With Dual Xeon

4U Rackmount SystemRevision: Draft

Doc #: AH041204-00 Date Revised: 4/12/04

CONFIDENTIAL Page 2of 26 PRODUCT DEVELOPMENT

APPROVED BY/DATE

DATE SIGNATURE

Test Conducted By:3/25 to

3/29/04

Report Written By: ____________ 4/12/04

Reviewed By:

REVISION HISTORY

Revision

Number

Date Changed By Affected Page

and Paragraph

Description

0 4/12/04 N/A N/A Original draft


3/26





1 EXECUTIVE SUMMARY OF RESULTS ..............................................................................................5

2 SCOPE OF THE TEST .............................................................................................................................5

3 TEST CONFIGURATION ........................................................................................................................5

4 TEST EQUIPMENT .................................................................................................................................. 6

5 TEST SETUP AND PROCEDURE .......................................................................................................... 6

6 BASELINE TEST RESULTS ...................................................................................................................9

6.1 NEBSGR-63 OFFICE VIBRATION IN FRONT/BACK ORIENTATION .................................................... 10

6.2 10GSHOCK RESPONSE IN FRONT/BACK ORIENTATION.....................................................................106.3 10GSHOCK RESPONSE IN SIDE/SIDE ORIENTATION .......................................................................... 12

6.4 NEBSGR-63 OFFICE VIBRATION IN SIDE/SIDE ORIENTATION ......................................................... 13

6.5 10GSHOCK RESPONSE IN TOP/BOTTOM ORIENTATION.....................................................................14

6.6 NEBSGR-63 OFFICE VIBRATION IN TOP/BOTTOM ORIENTATION.................................................... 166.7 RANDOM VIBRATION IN TOP/BOTTOM ORIENTATION ....................................................................... 17

6.8 20GSHOCK RESPONSE IN TOP/BOTTOM ORIENTATION.....................................................................17

6.9 RANDOM VIBRATION IN SIDE/SIDE ORIENTATION............................................................................. 19

6.10 20GSHOCK RESPONSE IN SIDE/SIDE ORIENTATION .......................................................................... 206.11 20GSHOCK RESPONSE IN FRONT/BACK ORIENTATION.....................................................................21

6.12 RANDOM VIBRATION IN FRONT/BACK ORIENTATION........................................................................ 23

7 CONCLUSION .........................................................................................................................................25


4/26





Figure 1: Up/Down vibration and shock orientation ........................................................................................ 6

Figure 2: Side/Side vibration and shock orientation......................................................................................... 7

Figure 3: Front/Back vibration and shock orientation..................................................................................... 7

Figure 4: Hard drive accelerometer placement................................................................................................. 8

Figure 5: Test monitoring and support equipment........................................................................................... 9

Figure 6: Front/back NEBS GR-63 office vibration ....................................................................................... 10

Figure 7: Positive 10G shock response in front/back orientation .................................................................. 11

Figure 8: Negative 10G shock response in front/back orientation................................................................ 11

Figure 9: Positive 10G shock response in side/side orientation...................................................................... 12

Figure 10: Negative 10G shock response in side/side orientation .................................................................. 13

Figure 11: Side/side NEBS GR-63 office vibration ......................................................................................... 14

Figure 12: Positive 10G shock response in top/bottom orientation ............................................................... 15

Figure 13: Negative 10G shock response in top/bottom orientation.............................................................. 15

Figure 14: Top/bottom NEBS GR-63 office vibration .................................................................................... 16

Figure 15: Top/bottom random vibration........................................................................................................ 17

Figure 16: Positive 20G shock response in top/bottom orientation ............................................................... 18Figure 17: Negative 20G shock response in top/bottom orientation.............................................................. 18

Figure 18: Side/side random vibration.............................................................................................................19

Figure 19: Positive 20G shock response in side/side orientation....................................................................20

Figure 20: Negative 20G shock response in side/side orientation .................................................................. 21

Figure 21: Positive 20G response in front/back orientation........................................................................... 22

Figure 22: Negative 20G response in front/back orientation ......................................................................... 22

Figure 23: Front/back random vibration......................................................................................................... 23

Figure 24: AGP card position before and after vibration/shock testing .......................................................24

Figure 25: NIC card position before and after vibration/shock testing ........................................................ 25

Table 1: Test Configuration................................................................................................................................ 5

Table 2: Test description and sequence .............................................................................................................9


5/26





1 Executive Summary of ResultsThe Customer cart provides for a unique operating environment for the computer

packaged inside. While the cart is being moved, the computer is being exposed to ashock and vibration environment that is different and potentially more severe than the

environment encountered in its shipping container.

The goal of the test was to expose the unpackaged computer to vibration and shock

stresses in order to quantify its immunity to such an environment. The unit did

experience a hard failure during the 12thand final test. The root cause was traced to one

of the hard drives that had become unseated from the backplane.

If the Customercart is capable of producing front-to-back shock pulses on the order of20 Gs and/or a random vibration spectrum similar in amplitude/frequency to the oneused during this test, then further design modification may be indicated.

2 Scopeof the Test

For the vibrationanalysis of the computer, the system shall be configured as close aspossible to the customers end product. The system shall have two accelerometers

placed on one of the hard drives as outlined in this document, Section 5: Test Setup

And Procedure. The system shall be stressed according to the NEBS GR-63 Officevibration, a random vibration profile, and shock events as outlined in Table 2.

3 Test Configuration

Table 1: Test Configuration

Component Description Qty

CCA-4ULHSRACKATX 1

CCZ-4UIDEBP 1

CCZ-CRU927614505 1

CCZ-INTUSBHUB 1

CDD-DWU14ABLK 1

CPU-P4X2400/533BP 2

HDD-ST3120022A 1

HDD-ST336607LW 1

MBA-X5DA8 1

MEM-M64X72F3200 2

MSP-13SNGUATA 1

MSP-18DUALUATA 1

MSP-MF046-042 2

NIC-AT2450FST 1

PSA-APWso34 1

SYK-S3LVDINT21 1

SYK-S68PM68HDF 1


6/26





SYK-USBADPTRCBL 1

VDC-QD980AGP128 1

Customer Unit Cart 1

Power Var Power Conditioner Model: ABC400-11 1

4 Test Equipment

Vibration table capable of creating vibration and shock profiles. This equipment

was furnished by and outside test facility. The equipment is comprised of an

Electro-dynamic shaker and applicable controller that created both the vibrationand shock profiles used in this test.

Equipment to collect acceleration data from the accelerometers on the hard drive.

This equipment was also furnished by the outside test facility.

Separate laptop computer to collect real-time data logs from unit under test.

Data logging software to run on Linux operating system. Software reports statusof unit under test in order to assess potential failure timing. This was written by

Dedicated Computing.

5 Test Setup and Procedure

1. The system was removed from the cart for vibration test purposes as we were onlyinterested in testing the computer and not the entire cart. Mounting hardware was

created to secure the computer to the vibration/shock table. The mounting bracket

and the 3 different test orientations are shown in Figure 1through Figure 3.

Figure 1: Up/Down vibration and shock orientation


7/26





Figure 2: Side/Side vibration and shock orientation

Figure 3: Front/Back vibration and shock orientation

2. Two (2) accelerometers were attached to one of the hard drives in order to monitor

acceleration levels encountered during all the tests. The location of the

accelerometers is shown in Figure 4.


8/26





Figure 4: Hard drive accelerometer placement

3. The system was subjected to the following vibration and shock stresses in the order

shown in Table 2.

Order Description Level Duration

1front/back

Nebs GR-63 office vibration.5 to 100 Hz at 0.1 dB/octave

0.1 G 1 sweep up from 5 to 100Hz, 1 sweep back down

(1hr26min total)

2front/back

Shock pulse for 6 ms half-sine

waveform

10G input 3 shocks in positive and 3 in

negative direction.

3side/side

Shock pulse for 6 ms half sine

waveform

10 G input 3 shocks in positive and 3 in

negative direction.

4side/side

Nebs GR-63 office vibration.

5 to 100 Hz at 0.1 dB/octave

0.1 G 1 sweep up from 5 to 100

Hz, 1 sweep back down

(1hr26min total)

5

up/down


waveform


negative direction.

6

up/down

Nebs GR-63 office vibration.

5 to 100 Hz at 0.1 dB/octave

0.1 G 1 sweep up from 5 to 100

Hz, 1 sweep back down(1hr26min total)

7

Up/down

Random vibration from 10 to 1000Hz 0.002

g^2/Hz

4 hours

8

Up/down


waveform


negative direction.

9

Side/side


g^2/Hz

4 hours

10 Shock pulse for 6 ms half sine 20 G input 3 shocks in positive and 3 in


9/26





Side/side waveform negative direction.

11

Front/back


waveform


negative direction.

12Front/back


g^2/Hz

4 hours

Table 2: Test description and sequence

4. A simple data logger was setup to run on the Customercomputer in order to track its

status during the test. The logging software was configured to send a status message

to the remote laptop every 3 seconds via a standard network cable. If theEndorcardial computer stopped functioning during test, then the logging software

would capture the failure time to within 3 seconds. After each test (as defined in

Table 2), the logging software would be stopped at which time the laptop would stop

writing the log file. The Customerbox was then re-booted in order to start a newlogging event as well as assure general function of the unit after each test.

The support equipment is shown in figure 5.

Figure 5: Test monitoring and support equipment

6 Baseline Test Results

The results for the vibration test are shown belowin the order defined in Table 2.


10/26





6.1 NEBS GR-63 Office Vibration in Front/Back Orientation

The accelerometer responses during the NEBS GR-63 office vibration in the front/back

configuration are shown in figure 6.

profile(f)

high-alarm(f)

low-alarm(f)

HD Front(f)

HD Top(f)

control(f)

100.005.0000 10.000

1.0000

0.0003

0.0010

0.0100

0.1000

Frequency (Hz)

gn

Figure 6: Front/back NEBS GR-63 office vibration

The profile response (shown in green) is difficult to see because it is completely

covered up by the control response (shown in black). This is a desirable result,indicating that the vibration controller is doing a good job of creating the desired profile.

The two accelerometers mounted on the hard drive are shown as HD Front (shown in

red) and HD Top (shown in light blue).

The HD front accelerometer did capture a slight amplification relative to the input that

peaked at ~90 Hz. The HD top was attenuated below the input for the entire test.

The unit completed this test with no failures.

6.2 10G Shock Response in Front/Back Orientation

The accelerometer responses during the 10 G shock in the front/back orientation areshown in figure 7(positive direction) and figure 8 (negative direction).


11/26





profile(t)

high-abort(t)

low-abort(t)

input2(t)

input3(t)

control(t)

0.0280-0.0015 0 0 .0025 0 .0050 0 .0075 0 .0100 0 .0125 0.0150 0 .0175 0 .0200 0 .0225 0 .0250

15.000

-25.000

-22.500

-20.000

-17.500

-15.000

-12.500

-10.000

-7.5000

-5.0000

-2.5000

0

2.5000

5.0000

7.5000

10.000

12.500

Time (Seconds)

G

Figure 7: Positive 10G shock response in front/back orientation

profile(t)

high-abort(t)

low-abort(t)

input2(t)

input3(t)

control(t)

0.0280-0.0015 0 0.0025 0 .0050 0 .0075 0 .0100 0 .0125 0 .0150 0 .0175 0 .0200 0 .0225 0 .0250

28.000

-25.000-24.000

-21.000

-18.000

-15.000

-12.000

-9.0000

-6.0000

-3.0000

0

3.0000

6.0000

9.0000

12.000

15.000

18.000

21.000

24.000

Time (Seconds)

G

Figure 8: Negative 10G shock response in front/back orientation


12/26





The Input 2 response of figures 7 and 8 (shown in magenta) is the same accelerometer

as HD front from Figure 6. The front of the hard drive saw a max acceleration of ~23

Gs when shocked in the positive direction, and ~21 Gs when shocked in the negativedirectionunder the 10 G input.

The Input 3 response of figures 7 and 8 (shown in light blue) is the sameaccelerometer as HD top from Figure 6. Its response never exceeded the 10G input.

The profile (shown in green) and control (shown in black) both track each other as

desired.

The unit completedthis test with no failures.

6.3 10G Shock Response in Side/Side OrientationThe accelerometer responses during the 10 G shock in the side/side orientation areshown in figure 9 (positive direction) and figure 10 (negative direction)

profile(t)

high-abort(t)

low-abort(t)

input2(t)

input3(t)

control(t)

0.0280-0.0015 0 0.0025 0 .0050 0 .0075 0 .0100 0 .0125 0 .0150 0 .0175 0 .0200 0 .0225 0 .0250

14.000

-16.000

-14.000

-12.000

-10.000

-8.0000

-6.0000

-4.0000

-2.0000

0

2.0000

4.0000

6.0000

8.0000

10.000

12.000

Time (Seconds)

G

Figure 9: Positive 10G shock response in side/side orientation


13/26





profile(t)

high-abort(t)

low-abort(t)

input2(t)

input3(t)

control(t)

0.0280-0.0015 0 0.0025 0 .0050 0 .0075 0 .0100 0 .0125 0 .0150 0 .0175 0 .0200 0 .0225 0 .0250

16.000

-14.000

-12.000

-10.000

-8.0000

-6.0000

-4.0000

-2.0000

0

2.0000

4.0000

6.0000

8.0000

10.000

12.000

14.000

Time (Seconds)

G

Figure 10: Negative 10G shock response in side/side orientation

The Input 2 response of figures 9 and 10 (shown in magenta) is the same

accelerometer as HD front from Figure 6. The Input 3 of figures 9 and 10 (shown

in light blue) is the same accelerometer as HD top from Figure 6. The response ofboth Input 2 and Input 3 never exceeded the 10G input, however neither of these

accelerometers was positioned to measure side/side response. Figure 4 shows that an

accelerometer was not positioned to measure in the side/side direction. Whenconsidering the shock data from the other two orientations, it is fair to assume that the

max acceleration in the side/side orientation was at or slightly above 20 Gs.


6.4 NEBS GR-63 Office Vibration in Side/Side Orientation

The accelerometer responses during the NEBS GR-63 office vibration in the side/side

orientation are shown in figure 11.


14/26





profile(f)

high-alarm(f)

low-alarm(f)

HD Front(f)

HD Top(f)

control(f)

100.005.0000 10.000

1.0000

0.0022

0.0100

0.1000

Frequency (Hz)

gn

Figure 11: Side/side NEBS GR-63 office vibration

Both hard drive responses (HD front and HD top) were below the input of 0.1Gs,

however as noted in the shock results there was no accelerometer on the hard drive to

measure response in this direction.


6.5 10G Shock Response in Top/Bottom Orientation

The accelerometer responses during the 10 G shock in the top/bottom orientation areshown in figure 12 (positive direction) and figure 13 (negative direction).


15/26





profile(t)

high-abort(t)

low-abort(t)

input2(t)

input3(t)

control(t)

0.0120-0.0015 0 0.0015 0.0030 0.0045 0.0060 0.0075 0.0090 0.0105

32.000

-24.000

-21.000

-18.000

-15.000

-12.000

-9.0000

-6.0000

-3.0000

0

3.0000

6.0000

9.0000

12.000

15.000

18.000

21.000

24.000

27.000

30.000

Time (Seconds)

G

Figure 12: Positive 10G shock response in top/bottom orientation

profile(t)

high-abort(t)

low-abort(t)

input2(t)

input3(t)

control(t)

0.0120-0.0015 0 0.0015 0.0030 0.0045 0.0060 0.0075 0.0090 0.0105

29.000

-24.000

-21.000

-18.000

-15.000

-12.000

-9.0000

-6.0000

-3.0000

0

3.0000

6.0000

9.0000

12.000

15.000

18.000

21.000

24.000

27.000

Time (Seconds)

G

Figure 13: Negative 10G shock response in top/bottom orientation


16/26





The Input 3 response of figures 12 and 13 (shown in light blue) is the same

accelerometer as HD top from Figure 6. The top of the hard drive saw a max

acceleration of ~29 Gs when shocked in the positive direction, and ~22 Gs whenshocked in the negative direction under the10 G input.

The Input 2 response of figures 12 and 13 (shown in magenta) is the sameaccelerometer as HD front from Figure 6. Its response never exceeded the 10G input.


6.6 NEBS GR-63 Office Vibration in Top/Bottom Orientation

The accelerometer responses during the NEBS GR-63 office vibration in the top/bottom

orientation are shown in figure 14.

profile(f)

high-alarm(f)

low-alarm(f)

HD Front(f)

HD Top(f)

control(f)

100.005.0000 10.000

1.0000

0.0022

0.0100

0.1000

Frequency (Hz)

gn

Figure 14: Top/bottom NEBS GR-63 office vibration

The two accelerometers mounted on the hard drive are shown as HD Front (shown in

red) and HD Top (shown in light blue). The HD Top accelerometer did capture a

slight amplification relative to the input that peaked at ~95 Hz. The HD front wasattenuated below the input for the entire test.

The unit completed this test with no failures


17/26





6.7 Random Vibration in Top/Bottom OrientationThe accelerometer responses during the Random vibration in the top/bottom orientation

are shown in figure 15.

profile(f)

high-alarm(f)

low-alarm(f)

input2(f)

input3(f)

control(f)

2000.05.0000 100.00 1000.0

0.2700

9.6E-061.0E-05

0.0001

0.0010

0.0100

0.1000

Frequency (Hz)

(G)2/Hz

Figure 15: Top/bottom random vibration

The Input 3 response of figures 15 (shown in light blue) is the same accelerometer as

HD top from Figure 6. The Input 2 response of Figure 15 (shown in red) is the

same accelerometer as HD Front from Figure 6. Unlike the NEBS vibration thatswept through a range of frequencies, this test subjects the unit to all of these

frequencies simultaneously for 4 hours per axis.

The unit passed this test without failure.

6.8 20G Shock Response in Top/Bottom Orientation

The accelerometer responses during the 20 G shock in the top/bottom orientation areshown in figure 16 (positive direction) and figure 17 (negative direction)


18/26





profile(t)

high-abort(t)

low-abort(t)

input2(t)

input3(t)

control(t)

0.0120-0.0015 0 0.0015 0.0030 0.0045 0.0060 0.0075 0.0090 0.0105

51.000

-35.000

-30.000

-25.000

-20.000

-15.000

-10.000

-5.0000

0

5.0000

10.000

15.000

20.000

25.000

30.000

35.000

40.000

45.000

Time (Seconds)

G

Figure 16: Positive 20G shock response in top/bottom orientation

profile(t)

high-abort(t)

low-abort(t)

input2(t)

input3(t)

control(t)

0.0120-0.0015 0 0.0015 0.0030 0.0045 0.0060 0.0075 0.0090 0.0105

35.000

-51.000-50.000

-45.000

-40.000

-35.000

-30.000

-25.000

-20.000

-15.000

-10.000

-5.0000

0

5.0000

10.000

15.000

20.000

25.000

30.000

Time (Seconds)

G

Figure 17: Negative 20G shock response in top/bottom orientation


19/26







acceleration of ~50 Gs when shocked in the positive direction, and ~38 Gs whenshocked in the negative direction under the 20 G input.

The Input 2 response of figures 16and 17(shown in magenta) is the sameaccelerometer as HD front from Figure 6. Its response never exceeded the 20G input.

The unit completed this test with nofailures.

6.9 Random Vibration in Side/Side Orientation

The accelerometer responses during the Random vibration in the side/side orientation


profile(f)

high-alarm(f)

low-alarm(f)

input2(f)

input3(f)

control(f)

2000.05.0000 100.00 1000.0

0.2700

9.6E-061.0E-05

0.0001

0.0010

0.0100

0.1000

Frequency (Hz)

(G)2/Hz

Figure 18: Side/side random vibration

The Input 3 response of figures 18 (shown in light blue) is the same accelerometer as

HD top from Figure 6. The Input 2 response of Figure 18 (shown in red) is the

same accelerometer as HD Front from Figure 6.

The unit completed this test without failures.


20/26





6.10 20G Shock Response in Side/Side Orientation

The first indication of any problem occurred during the re-boot after side/side random

vibration was complete but before 20G side/side shock had started. During boot of theCustomersystem, the following message appeared on the screen:

EXT 3-fs error (device sd(8,2)) in start_transaction: Journal has aborted

A reset solved the problem and the system booted fine during the next attempt.

The accelerometer responses during the 20 G shock in the side/side orientation are

shown in figure 19 (positive direction) and figure 20 (negative direction).

profile(t)

high-abort(t)

low-abort(t)

input2(t)

input3(t)

control(t)

0.0120-0.0015 0 0.0015 0.0030 0.0045 0.0060 0.0075 0.0090 0.0105

35.000

-51.000-50.000

-45.000

-40.000

-35.000

-30.000

-25.000

-20.000

-15.000

-10.000

-5.0000

0

5.0000

10.000

15.000

20.000

25.000

30.000

Time (Seconds)

G

Figure 19: Positive 20G shock response in side/side orientation


21/26





profile(t)

high-abort(t)

low-abort(t)

input2(t)

input3(t)

control(t)

0.0120-0.0015 0 0.0015 0.0030 0.0045 0.0060 0.0075 0.0090 0.0105

51.000

-35.000

-30.000

-25.000

-20.000

-15.000

-10.000

-5.0000

0

5.0000

10.000

15.000

20.000

25.000

30.000

35.000

40.000

45.000

Time (Seconds)

G

Figure 20: Negative 20G shock response in side/side orientation

The Input 2 response of figures 19 and 20 (shown in magenta) is the same

accelerometer as HD front from Figure 6. The Input 3 of figures 19 and 20 (shown

in light blue) is the same accelerometer as HD top from Figure 6. The response ofInput 2 never exceeded the 20G input and Input 3 just barely exceeded the 20G

input in the positive direction(23 Gs). Neither of these accelerometers was positioned

to measure side/side response. Figure 4 shows that an accelerometer was not positionedto measure in the side/side direction. When considering the shock data from the other

two orientations, it is fair to assume that the max acceleration in the side/side

orientation was at or above 45 Gs.


6.11 20G Shock Response in Front/Back Orientation

The accelerometer responses during the 20 G shock in the front/back orientation areshown in figure 21 (positive direction) and figure 22 (negative direction).


22/26





profile(t)

high-abort(t)

low-abort(t)

input2(t)

input3(t)

control(t)

0.0120-0.0015 0 0.0015 0.0030 0.0045 0.0060 0.0075 0.0090 0.0105

60.000

-35.000

-30.000

-25.000

-20.000

-15.000

-10.000

-5.0000

0

5.0000

10.000

15.000

20.000

25.000

30.000

35.000

40.000

45.000

50.000

55.000

Time (Seconds)

G

Figure 21: Positive 20G response in front/back orientation

profile(t)

high-abort(t)

low-abort(t)

input2(t)

input3(t)

control(t)

0.0120-0.0015 0 0.0015 0.0030 0.0045 0.0060 0.0075 0.0090 0.0105

35.000

-60.000

-55.000

-50.000

-45.000

-40.000

-35.000

-30.000

-25.000

-20.000

-15.000

-10.000

-5.0000

0

5.0000

10.000

15.000

20.00025.000

30.000

Time (Seconds)

G

Figure 22: Negative 20G response in front/back orientation


23/26







acceleration of ~50 Gs when shocked in the positive direction. The response on the topof the drive never exceeded the input in the negative direction.

The Input 2 response of figures 21 and 22 (shown in magenta) is the sameaccelerometer as HD front from Figure 6. The front of the hard drive experienced a

max acceleration of 55Gs in the positive direction and ~37Gs in the negative

direction. Something about the mechanical constraints on the hard drive dampens theresponse in the negative direction.


6.12 Random Vibration in Front/Back Orientation

The accelerometer responses during the Random vibration in the front/back orientation


profile(f)

high-alarm(f)

low-alarm(f)

input2(f)

input3(f)

control(f)

2000.05.0000 100.00 1000.0

0.2700

9.6E-061.0E-05

0.0001

0.0010

0.0100

0.1000

Frequency (Hz)

(G)2/Hz

Figure 23: Front/back random vibration

The logging software stopped logging 1min 34sec into the test. The mouse did not

respond, however the video feed from the Customerbox to the monitor was still alive.

The vibration equipment was paused and the system was re-booted.


24/26





The system booted without issue and the logging software was started again. This time,

the logging software stopped functioning 6min 48sec into the test. The mouse,

keyboard, and monitor were alive however the Customersystem was no longer sendingstatus to the laptop. The vibration continued to complete the 4 hour test even though

the unit was not logging.

After the vibration stopped, a reset was attempted but was not successful in booting the

system. A hard power reset was tried next and was also unsuccessful.

The cover was removed from the Customersystem. It was noted that the AGP and NIC

cards had both unseated slightly from their slots. See Figure 24 (AGP) and Figure 25

(NIC).

Slightly Unseated (after shockand vibration testing)

Fully seated (before shock andvibration testing)

Note difference

Figure 24: AGP card position before and after vibration/shock testing


25/26





Slightly Unseated (after shockand vibration testing)

Fully seated (before shock andvibration testing)

Note difference in

contact finger visibility

Figure 25: NIC card position before and after vibration/shock testing

Both cards were re-seated into their slots;however this did not remedy to boot problem.

As noted in section 6.12, the video feed to the Customer monitor never failed indicating

that the slight movement of the ACP card did not cause any failures. Additionally,communication was re-established between laptop and the Customersystem after re-

boot during the early troubles identified in section 6.12; indicating that the NIC cardwas not part of the problem either.

The Customer unit was removed from the vibration equipment and brought back to

dedicated computing for further root cause analysis.

The SCSI drive was first suspected to be the problem. It was removed and replaced

with a known good drive. The system still did not re-boot. The root cause was finallyidentified to be the hard drive that had the accelerometers attached to it. After re-seating the drive against the back plane the system booted and no other problems were

identified.

7 Conclusion

The unpackaged Customer system passed the NEBS GR-63 office vibration and 10Gshock testing in all 3 axis.

Problems didnt arise until the unit was subjected to the higher stresses during therandom vibration and 20G shock input. The first indication of a problem didnt occur


26/26




until after side/side random vibration (test 9 of 12), and this error did not repeat itself

through the subsequent 20 G side/side shock(test 10 of 12).

The hard failure didnt occur until front/back random vibration (the last test), which

was performed after completing 20G front/back shock (test 11 of 12). The shock and

vibration stresses in the front/back direction were in the direction that the hard drivewould need to move in order to unseatfrom the backplane.

If the Customer cart is capable of introducing shock pulses near 20Gs or a vibrationspectrumsimilar in frequency content and amplitude to the random profile used during

test, then the computer system could encounter failures in operation. Given the

orientation that the system is mounted inside the cart, it is likely that the most severeshock and vibration inputs from the cart would be in the top/bottom direction. The

system did function through all the stresses in this orientation. Stresses in the top/bottomorientation were likely responsible for the small movement of both the NIC and AGPgraphics card, however neither card was moved far enough to cause any problems.

report - vibration test

Documents