5800 Refrigerated Sampler Service Guide - Isco

5800 Refrigerated Sampler Service Guide
Section 5 Electrical Troubleshooting and Diagnostics
5.1.1 Test ‘RAM’ The TEST ‘RAM’ diagnostic tests the sampler’s memory that is
used dynamically by the sampler’s processor and holds program
settings and sample event data. This test loads 16-bit words into
memory and reads it back to confirm that the memory is working
correctly.
To run the test:
SELECT DIAG: ()
TEST 'RAM'
...TESTING 'RAM'
'RAM' PASSED
1. Select the TEST ‘RAM’ option and press Enter.
2. Wait for the sampler to complete the test.
3. When finished, the sampler displays the test results.
If the sampler reports ‘RAM’ FAILED contact your authorized Isco
service facility or the Teledyne Isco factory.
5.1.2 Test ‘ROM’ The TEST ‘ROM’ diagnostic tests the sampler’s Read-Only
Memory which holds the sampler software. It calculates a
checksum total of the data held in this memory and compares it
with a known value. If the checksum matches, the ROM test
passes.
To run the test:
SELECT DIAG: ()
TEST 'ROM'
...TESTING 'ROM'
'ROM' PASSED
1. Select the TEST ‘ROM’ option and press Enter.
2. Wait for the sampler to complete the test.
3. When finished, the sampler displays the test results.
If the sampler reports ‘ROM’ FAILED contact your authorized Isco
service facility or the Teledyne Isco factory.
English-language only samplers do not include the known value.
For these samplers, the test will report NO CHECKSUM. This
result does not indicate a pass or fail state, only that the ROM
test is not valid for this particular sampler.
5.1.3 Test Display The TEST DISPLAY diagnostic tests the sampler’s LCD display. It
cycles blocks of pixels on and off, then displays characters on the
screen. There is no pass or fail message. The technician must
watch the display to determine if it is faulty.
To run the test:
SELECT DIAG: ()
TEST DISPLAY
ABCDEFGHIJKLMNOPQRST
ABCDEFGHIJKLMNOPQRST
1. Select the TEST DISPLAY option and press Enter.
2. The sampler marches solid boxes across the display, followed
by characters. Observe the display. Evidence of a
faulty display may include:
· pixels that never turn on
· pixels that always stay on
· garbled text
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