A1 Assembly Removal - Agilent Technologies 4284A Service Manual

3-8-2. A1 ASSEMBLY REMOVAL

1 . Loosen the two screws which secure the left hand side top shield plate . Don ' t
completely remove them.
There are two top shield plates. To gain access to the A1 assem bly, remove the
top shield plate which has the WARNING message printed on it.
CAPACITORS ON THE A1 BOARD REMAIN CHARGED WITH HAZARDOUS VOLT­
AGES FOR A PERIOD OF TIME AFTER THE INSTRUM ENT IS TURNED OFF, O R
AFTER THE POWER CABLE I S DISCONN ECTED.
M I N UTE FOR T H E CAPACITORS T O DISCHARGE AFTER T H E I NSTRUMENT I S
TURNED OFF O R THE POWER CABLE I S D ISCONNECTED.
2. Slide the top shield plate towards the front and lift it off.
3. Lift the black and the brown board extractors at the top corners of the A 1
assembly.
4 . Disconnect the cable that connects between the A 1 board assembly and the rear
panel.
3-8-3. REMOVI NG THE A2, A3, A4, A5, A6, A7, A20, A30, A31, A40, OR A50 ASSEMBLIES
1 . Loosen the five screws that secure the right hand side plate. Don't remove the
screws completely.
There are two top shield plates. In order to access the A2 , A3, A4, A5, A6, A7,
A20 , A30, A3 1 , A40, or A50 assemblies, remove the top shield plate o n which the
WARNING message label is NOT printed .
2 . Slide the top shield plate towards the front and lift it off.
3 . Lift the extractors at top corners of the board assembly that you want to remove.
NOTE
ALLOW AT LEAST O N E
NOTE
3-1 7