Fluke 2640A Service Manual page 184

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Service Manual
Error
Code
1 Bad boot software
image in FLASH
ROM.
2 Bad main software
image in FLASH
ROM.
3 RAM test failure.
5-20
Table 5-10. Relating Selftest Errors to Instrument Problems
Suspect
Error Code
Assembly
Description
A1 Main
PCA
A1 Main
PCA
A1 Main
PCA
Error Code
Discussion
Background The A1U21 FLASH memory device is
divided into sections. One of these sections is the
memory for the boot software, which is used for
instrument initialization. After the instrument is initialized,
the main code takes over and runs the instrument.
Failure For this error to occur, the boot software is either
missing or is corrupted and must be reloaded.
Correction Reloading the boot software is a factory
procedure only. The only recourse is to order a new
A1U21 device programmed at the factory if the software
is corrupted. Also see "Troubleshooting the Digital
Kernel."
Background The A1U21 FLASH memory device is
divided into sections. One of these sections is the main
software that runs the instrument.
Failure For this error to occur, the main software is either
missing or is corrupted and must be reloaded. This failure
is detected by a boot monitor condition, which means the
boot software completed but the main software did not
take over instrument operation.
Correction Reloading the main software is discussed in
"Updating Embedded Instrument Firmware" later in this
chapter. Also see "Troubleshooting the Digital Kernel."
Background The A1U20, A1U30, A1U34, and A1U35
static RAM devices are divided into two banks: RAM1
(A1U20 and A1U30) and RAM2 (A1U34 and A1U35). The
boot software uses a portion of RAM1 as a memory
device.
Failure For this error to occur, the RAM1 devices did not
function correctly during the boot process. Either the RAM
devices failed, or the address decoding for the RAM
devices failed. Most of the address decoding is located
internal to the A1U1 microprocessor, while the RAM1*
and RAM2* enable signals are generated by logic devices
A1U14 and A1U15 from A1U1 address bits 18 and 20.
Note that depending on the RAM devices used,
resistor/jumpers A1R125 and A1R126 (near A1U14) may
or may not be used.
Correction Check the enable signals at the RAM
devices, including the enable RAM1* and read/write
signals. If the inputs are correct, the devices themselves
are suspect. If the inputs are incorrect, work backwards
towards the signal source and locate the device that is not
performing. Also see "Troubleshooting the Digital Kernel."
Check the A1U29 I/O and Memory Decoder to make sure
the proper enables and strobes are produced.