Instruction manual

Chapter 3 Replacing Assemblies
To Remove A1 Motherboard Assembly
Assembly-Level Service Guide 3-9
3
To Remove A1 Motherboard Assembly
1 Remove the cover.
See the section titled “To Remove the Cover” in this chapter.
2 Remove the Power Supply Assembly.
See the section titled “To Remove A4 AC Power Supply Assembly” in this chapter.
3 Remove the front bezel.
See the section titled “To Remove the Front Bezel” in this chapter.
4 If the Counter contains Option 015/030/050/124 1.5/3.0/5.0/12.4 GHz Channel,
disconnect the optional channel’s flat-ribbon cable from J7 on A1 Motherboard
Assembly as shown in Figure 3-6.
5 If the Counter contains one of the optional high stability timebase assemblies
(Option 001, 010, 012), disconnect the flat-ribbon cable from J6 of A1
Motherboard as shown in Figure 2-8A (See Chapter 2, “Service.”).
6 If the Counter contains the Option 002 DC Power Input Assembly, remove it.
See the section titled “To Remove A5 DC Power Input Assembly (Option 002)” in
this chapter.
7 Remove the two hex screws (H4), shown in Figure 3-6, on the rear-panel GPIB
connector using the 7-mm spin tight.