ASC-Lite Chassis Theory and Troubleshooting

1 Diagnostics

There are UPM Diagnostics that can be found on the Common Service Desktop. Details on these diagnostics can be found in Peripheral Diagnostics.

2 Reference Documents / Vendor Manuals

3 LED Descriptions

3.1 Input Panel

Connections to input power and CAN communication. ON/OFF switch for entire ASC-Lite Chassis. Reset Button will reset both UPMs; however, any measured RF power from the scanner is NOT reset. Voltage banana jacks are for checks of the power supply.

3.2 Power Supply

The power supply provides 3.3V, 5.0V, +12V and –12V to the UPM processor UPM detector boardsand RF interface baords.

3.3 Processor Board

The processor board for UPM1 and UPM2 are identical. These boards collect sample data from the detector boards, calculate the RF power and inhibit the scan if the trip limits have been exceeded or if some other UPM error occurs

3.4 RF Detector Boards

ASC-Lite has 2 RF detector boards. Each RF detector boards are identical. These boards convert measured RF power into a digital signal that is sent to the processor boards. Each board has two channels and each channel has 3 RF input ports, see details in the table below.

Table 1. RF Detector Boards
DETECTOR BOARD	NARROW BAND RF DETECTOR BOARD
Channel 1 FWD	Body Forward
Channel 1 REF 1	Body Reflected
Channel 1 REF 2	Body Hybrid Reflected (Not Used)
Channel 2 FWD	Body Forward
Channel 2 REF 1	Body Reflected
Channel 2 REF 2	Body Hybrid Reflected (Not Used)

3.5 RF Interface Boards

This board permits the host to control and monitor the operation of the SRFD3. The board controls the Narrowband RF amp.

3.6 UPM1 / UPM2

Every system contains two (redundant) UPM’s. These UPM’s are identical and boards can be swapped between the two for troubleshooting; see UPM Board Swap Procedure for details.

note:

A 50 Ohm Terminator is required on any RF port on the RF Detector Boards that is not being used.

Table 2. UPM 1 or UPM 2
LED NAME	DESCRIPTION
Sense	If ON, the RF Detector board is detecting RF input signal into one of the 3 ports on that Channel. If the Sense LED is OFF, then no signal is detected on that channel.
1.5V	1.5V as reference voltage made in board.
CAN Power	If ON, the 24V from the CAN power supply is detected. Note that this voltage is provided via the CAN communication cable connected to the UPM Processor board. So, this LED should be ON even if the UPM is powered down.
CAN Status	If the CAN status blinks once, then the processor board is attempting to communicate with the MGD host. If the LED blinks twice, then the processor board is communicating with the MGD system. If LED remains OFF, then the processor board is not attempting communication with the host.
Inhibit	If this LED is ON, then the UPM has detected some sort of fault and has inhibited any scanning. The LED will remain ON until the fault is cleared. Check the error log for details on the fault. For excessive power faults, it will clear once the power level is less than 99% of the trip limit.

4 UPM Calibration Troubleshooting

4.1 Theory

The UPM calibration runs a pcal scan and adjusts digital attenuators internal to the UPM to match the expected RF signal level.

The UPM calibration parameters found in the UPM calibration files are used in the calibration/functional check program. The program code sets the digital attenuators in the UPM based on the results of the 3 calibrations per channel (forward, reflected and hybrid reflected (if applicable)), and a comparison to these UPM calibration parameters. This calibration file is accessible from within the UPM calibration tool from the “File” pull down menu, “Edit Config” option.

The final UPM digital attenuator values are written to the UPM Calibration Configuration files (UpmCal1.cfg, UpmCal2.cfg) located in directory: w/config. There can be substantial variation in these calibration values from port to port, or on the same port following the replacement of any hardware.

Prior to starting the troubleshooting of the UPM, you can save the current calibration files as the Default backup. This can be done by entering the UPM calibration tool, selecting File and BKUP UPM Cal. After troubleshooting, if the UPM is restored in its original configuration (ie, each board is in its original location) you can restore the backup calibration file by opening the UPM calibration tool, selecting File and Restore BKUP UPM Cal. (The following error message may appear: "Warning: single selection listbox control requires that the Value be an integer range. Control will not be rendered until all of its parameter values are valid."….this error can be ignored)

4.2 Troubleshooting

If the UPM calibration fails, first check the system error log. Use the Problem/Solution Table in Section 7 to troubleshoot the errors in the error log. If Problem / Solution Table does not solve the calibration errors, attempt the following steps:

Quit UPM Calibration tool, end any open exams and TPS reset.
Open a new exam, Patient ID: geservice, weight: 111 lbs.
Select Service, Other.
Select apb cal (series 1 if t/s body and series 2 if t/s head).
Select Save Series.
Make sure that the correct hardware setup exists (ie cables connections and dummy load connections match setup in documentation).
Click on Manual Pre-scan.
Change TG to 200 if troubleshooting UPM Forward Power Calibration.
Click on Scan TR.
Check for inhibit light on ASC/UPM Chassis, Driver Module.
Check for Sense LED’s flashing on the correct channel (both RF Detector boards should have one of the channel’s Sense LEDs flashing, matching the Channel you are troubleshooting).
Stop MPS.

The system must be able to scan with the correct UPM Sense LEDs flashing prior to running the calibration. If the Sense LEDs are not flashing, check the error log to determine if the scan was stopped. Also check that the hardware setup is correct.

If setup and system are okay but the Sense lights are not flashing, make sure RF is getting to the UPM by placing a 50 Ohm terminator in the port you are troubleshooting and the UPM RF cable into a 50ohm terminated scope. Make sure you see a RF signal, if no signal exists, attempt reading at various points along the cable path to determine where the signal is lost. If a signal exists, attempt swapping/replacing RF Detector boards.

5 UPM Functional Check Troubleshooting

The UPM Functional check runs a prescribed scan in the RF Chain selected. It compares the measured RF power from the UPM to the expected value in a config file. If the values do not fall within 12%, then the functional check will fail.

In addition, the functional check confirms the UPM will stop scanning if the RF measured exceeds the trip limit

If the functional check fails to run, first check the system error log. Proceed toProblem / Solution Table for troubleshooting UPM system errors.

If the functional check fails due to inaccurate power measurement recalibrate the UPM then attempt the functional check again

6 Problem / Solution Table

Table 3. Problem - Solution Table
FAULT DESCRIPTION	PROBLEM DESCRIPTION	GE FIELD ACTION
EM_SCP_STOP_ACTION_UPM_ERRORUniversal Power Monitor error occurred.	General fault	This is a general UPM fault; view other errors in error log for more details.
EM_POWER_FAULT_WARNINGPower Monitor Warning: % percent of limit reached for the XX Average.	General high power warning	This is a general warning that the scan approached the Peak RF power limit. No action required.
EM_LARGE_DIFFERENCE_DETECTED. Large difference was detected between the two Power Monitors. Difference is in the (Long/short term) Average. Monitor 1 reads XX W/kg Monitor 2 reads YY W/kg	The power levels detected by the UPMs differ greatly. Error can occur during the calibration process. If this error occurs during UPM Calibrations, ignore Error can also occur during troubleshooting if UPM boards have been swapped. Return boards to original spot or run UPM calibrations.	Calibrate and run the UPM functional check. If error continues, go to Section 8 and swap the RF Detector boards. Recalibrate and run the UPM functional check. If lower value follows board, order new board. Try replacing one board, recalibrate and run the functional check. If error continues, replace other board; recalibrate and run functional check. If lower RF value doesn’t follow RF Detector board, swap the cables running into the RF Detector boards. Recalibrate and run the UPM functional check. If lower value moves to other UPM, then check resistance of both cable runs. If the resistance of the cables are equal, then replace the RF couplers internal to the effected RF Amp (couplers may not be the FRU, actual FRU is dependant on amplifier type). If 1, 2 and 3 do not fix the issue, then replace the one of the UPM Processor boards
EM_UPM_FPGA_SN_FLTThe (UPM1/2) has detected that the FPGA was unable to read serial number information.	The FPGA was unable to read serial number information from (RF Detector/RF Processor)UPM board. This could be caused by an old revision of FPGA code or a hardware problem.	Go to UPM Board Swap Procedure and swap Detector boards If root cause not determined, go to Section 8 and swap Processor boards If root cause not determined, replace the ASC Chassis
EM_UPM_PWR_FLT_DETECTThe (UPM1/2) has detected an Invalid Power Fault on the (Head/Body/MNS/CW) Amplifier.	The UPM detected RF power out of an amplifier port that should not have been producing RF at that time.	Capture the protocol/sequence that produces this error repeatedly, then follow the following steps. If only one of the UPM’s detects this error, then go to UPM Board Swap Procedure and swap the effected RF Detector boards. If only one of the UPM’s detects this error and step 2 was attempted with no success, go to UPM Board Swap Procedure and swap the Processor boards. If both UPM’s indicate this failure, or steps 2 and 3 were attempted with no success, then proceed with troubleshooting the un-blank signal and affected RF Amplifier as this indicates a system fault.
EM_UPM_PWR_LIMIT_EXCEEDThe (UPM1/2) detected a Power Fault on the (Short/Long Term) Average.Calculated Average =XXLimit =XX	This indicates that the UPM detected power that exceeded the trip limit for the area scanned	Customer should check the protocol to determine if it produces excessive SAR. Protocol should be approved by GE Apps specialist if applicable. If the protocol is acceptable, calibrate UPM and run the UPM functional check. If the trip is consistently on one of the UPM’s, proceed to Section 8 and swap the RF Detector boards. Make sure to recalibrate the UPM after the swap. If the faults follow the RF Detector board, replace it. If the fault doesn’t follow the RF Detector board, replace the ASC Chassis.
EM_RF_NB_BOARD_MISSINGNB Detector Board Missing	UPM detects that a NB RF Detector board is missing	Attempt to reseat both RF Detector boards, check for bent/broken pins on backplane and board. Proceed to UPM Board Swap Procedure and swap Detector boards. If error doesn’t follow the Detector board, proceed to Section 8 and swap Processor boards If the cause of error cannot be determined by Steps 1-3, replace ASC Chassis.
EM_BUS_SELFTEST_FAILThe UPM1/2 failed its BUS Self Test on the XXChannel Expected Data : X% Detected Data : Y%	This is a failure of the data bus from the RF detector board, through the ASC backplane to the processor board.	Proceed to UPM Board Swap Procedure and swap RF Detector boards. If the RF Detector board is no the failure, then proceed to Section 8 and swap the Processor boards. If both RF Detector and Processor boards are okay, replace the ASC Chassis
EM_DAC_SELFTEST_FAILThe (Upm1/2) failed its DAC Self Test on the XX Channel. Expected Data : X Detected Data : Y	This is a failure of the digital to analog converter on the RF detector board.	Proceed to UPM Board Swap Procedure and swap RF Detector boards. If the RF Detector board is no the failure, then proceed to UPM Board Swap Procedure and swap the Processor boards. If both RF Detector and Processor boards are okay, replace the ASC Chassis.
EM_LUT_SELFTEST_FAILThe (UPM1/2) failed its LUT Self Test on the XX Channel. Expected Data : 0x%x. Detected Data : 0x%x.	The LUT = Look up Table. This is a failure of the processor board.	Proceed to UPM Board Swap Procedure and swap the Processor boards. If the processor board is not the root cause, replace the ASC Chassis.
EM_NB_LUT_TABLE_LOAD_FAILThe UPM1/2 Look Up Table Failed on the Narrow Band RF Detector board.Number of Write Failures: ##	The LUT = Look up Table. This is a failure of the processor board	Proceed to UPM Board Swap Procedure and swap the Processor boards. If the processor board is not the root cause, replace the ASC Chassis.
EM_SCP_UPM_SHORT_TERM_REG_FAIL (Head/Body/Extremity/Other) Short Term Limit Write Fail. Head Present Limit: XX Body Present Limit: XX Extremity Present Limit: XX Other Present Limit: XX	A value written to the register was read back as a different value.	Don’t change any hardware, as this could normally appear during resets or when s/w out of sink with the UPM. If the failure continues, replace the processor board.
EM_SCP_UPM_LONG_TERM_REG_FAIL (Head/Body/Extremity/Other) Short Term Limit Write Fail. Head Present Limit: XX Body Present Limit: XX Extremity Present Limit: XX Other Present Limit: XX	A value written to the register was read back as a different value.	Don’t change any hardware, as this could normally appear during resets or when s/w out of sink with the UPM. If the failure continues, replace the processor board.
EM_UPM_CALIBRATION_FAILThe (UPM1/2) detected a Calibration failure on the ADC.Calibration Pass BitMap = XX	The Analog to Digital converter on the RF Detector board failed to autocal properly.	Reseat RF Detector board, checking for bent bins on both the boards and backplane. If failure occurs only on 1 board, use Section 8 to swap RF detector boards. If steps 1&2 don’t determine the root cause, then use Section 8 and swap the processor boards If steps 1, 2 and 3 don’t determine root cause, replace the ASC Chassis.
EM_UPM_CAN_SELFTESTThe (UPM1/2) failed its CAN selftest.The CAN module on the DSP failed its self test procedure…	The fault indicates a failure in the CAN DSP, which is located on the UPM Processor board.	Pull out and reseat both processor boards and the power supply. Run the UPM I/O Diagnostics to see if the error has cleared. If error continues, replace the effected UPM Processor Board.
EM_UPM_FPGAThe (UPM1/2) Has Detected a FPGA error.Source of Fault is (one of the following):FPGA Read/Write failureFPGA INIT not ready	The fault indicates a failure in the FPGA which is located on the UPM Processor board.	Pull out and reseat both processor boards and the power supply. Run the UPM I/O Diagnostics to see if the error has cleared. If error continues, replace the effected UPM Processor Board.
EM_UPM_NOT_CALIBRATEDThe UPM1/2 has not been Calibrated.No Scanning will be Allowed until Calibrated.	This fault occurs when the UPM has not been calibrated.	Calibrate the UPM and perform the UPM functional check.
EM_UPM_PS_FAULTThe (UPM1/2) Has Detected a Power Supply Fault. Source of Fault is (one of the following): UPB +12 Volts UPB -12 Volts UPB +5 Volts UPB +3.3 Volts UPB +1.5 Volts UPB +1.65 Volts Actual Voltage = ## Limit Voltage = ## The UPM detected a problem with one of its power supplies. note: the fault indicates RF, then proceed to next row in this table.	This fault occurs when the UPM processor board detects incorrect power from the power supply. This is due to a failed power supply, backplane, processor board or a processor board or power supply that is not seated correctly in its slot.	Pull out and reseat both processor boards and the power supply. Run the UPM Analog Diagnostics to see if the error has cleared. Check the voltages using a DMM at the Input Panel of the UPM. If these voltage levels confirm the fault description, then replace the UPM Power Supply. If the error is only coming from 1 UPM consistently, proceed to Section 8 and swap the UPM Processor boards. Check that the incoming power is 110 to 130VAC 50/60Hz. If the error continues after attempting the above, replace the UPM Chassis as it this indicates a failure
EM_UPM_PS_FAULTThe (UPM1/2) Has Detected a Power Supply Fault.Source of Fault is (one of the following): RF NB +12 Volts RF MNS +12 Volts RF NB +5 Volts RF MNS +5 Volts RF NB +3.3 Volts RF MNS +3.3 Volts RF NB Ref Voltage RF MNS Ref Voltage Actual Voltage = ## Limit Voltage = ## The UPM detected a problem with power on a RF Detector board.	The issue is either with a supply voltage on one of the detector boards or with the monitoring of that supply voltage on the associated UPM Processor board	Pull out and reseat effected processor board and RF detector board If the error is only coming from 1 UPM consistently, proceed to UPM Board Swap Procedure and swap the UPM RF Detector boards. If error doesn’t follow RF Detector boards, then proceed to UPM Board Swap Procedure and swap the UPM Processor boards. If error is still on the same UPM, then replace ASC Chassis.
EM_UPM_FILE_OPEN_FAILUnable to open the YY file. Please fix and TPS Reset.	Caused due to software config file missing	Error should state the file name and location. Attempt restore info; otherwise a s/w load may be required.
EM_UPM_CAL_FAIL_EMULATEDUnable to Calibrate the UPM because it is emulated out. Please remove emulationand TPS Reset.	UPM is emulated out	Remove UPM emulation from mgd_stage file. TPS reset and recalibrate.
EM_UPM_CAL_FAIL_FILE_OPENUPM Calibration failed due to failure to open XX file.	Caused due to software config file missing.	Error should state the file name and location. Attempt restore info; otherwise a s/w load may be required.
EM_UPM_CAL_FAIL_POWER"UPM Calibration failed due to failure to converge on a calibration point. Verify that power is applied on the proper channel on the UPM."	UPM calibration failure, the UPM attempted to calibrate to applied power; however, could not match value required	Go to UPM Calibration Troubleshooting, UPM calibration troubleshooting
EM_UPM_CAL_TIMEOUT"UPM Calibration failed due to a timeout on the Calibration process.Verify that the UPM is powered up and all cables are connected properly."	UPM calibration failure, the UPM attempted to calibrate to applied power; however, could not match value required	Go to UPM Calibration Troubleshooting, UPM calibration troubleshooting

7 UPM Board Swap Procedure

UPM Board Swap Test

note:

If either the Processor Board or RF Detector boards are swapped, the UPM calibration and functional check must be run prior to patient scanning.