Discovery MR750 3.0T System Service Methods
5690009-2EN Revision 4
Object ID: 00000018WIA30481E20GYZ
Topic ID: id_13106474 Version: 5.1
Date: Jul 13, 2021 7:09:35 PM

KASC assembly replacement

Prerequisites

Table 1. Personnel requirements
Required persons	Preliminary requirements	Procedure	Finalization
1	Not Applicable	30 minutes	For DV: 30 mins. For Voyager and Pioneer: 60 mins.

Table 2. Tools and test equipment
Item	Quantity	Effectivity	Part number	Manufacturer
Standard Tool	1	-	-	-
RF power measurement kit (use one of the following kits):	1	-	EITHER 5307511-2 or 5307511-3 (Bird wattmeter)	-

Table 3. Replacement parts
Item	Quantity	Effectivity	Part number	Manufacturer
KASC Assembly	1	-	Refer to FRU Manual	-

Table 4. Safety

Warning

ELECTROCUTION HAZARD!

DANGEROUS AND/OR FATAL VOLTAGES ARE PRESENT IN THE ENERGIZED CABINET.

Follow loto steps as given in first section of this document to disable and verify safe voltage levels.

Note:

The unit can be withdrawn with the slide rail.

Procedure

Notice

NEVER use the power button on the front to turn an ICN ON/OFF. The ICNs have software running on disk drives that can be corrupted if not shut down properly. Follow the procedure referenced below for removing power to the ICN chassis. Failure to properly power down an ICN can result in premature ICN failure.

From the Common Service Desktop, turn off the ICN(s) (see ICN On/Off Procedure).

Complete LOTO for reconstruction equipment. See the latest revision of the MR Service Safety Manual, PN 5452735, available from the online documentation library.
In the PEN cabinet, turn off the circuit breaker to the driver module.

Figure 1. Driver module circuit breaker (in PEN cabinet)
Open the PGR cabinet.
Disconnect all connectors and cables from KASC.

Figure 2. KASC assembly and cables
Remove the KASC assembly as follows:
1. Remove four screws.
2. Slide the KASC out.
Figure 3. KASC assembly
Install the new module by reverse order of removal.

Finalization

Restore the power.
In the PEN cabinet, turn on the circuit breaker to the driver module.
Remove LOTO from the reconstruction equipment. See the MR Service Safety Manual, PN 5452735.
Turn on the ICNs per the ICN On/Off Procedure.
Note: For the first 3 or 4 minutes, LEDs come on only at the rear of the ICN, next to the power cables. After 3 to 4 minutes, you will hear the ICN fans come on, and then the LED at the front of the ICN starts to flash.
Do Calibrating RF Amplifier and UPM.
Do a TPS Reset, and then do a check scan to make sure the system operates correctly.