Agilent Technologies 856290216 service manual MHz Reference at A15J302 RF Section

b. Check U305 pin 3 for approximately +12 Vdc (Option 103 only).

c. Check for a 10 MHz sine wave greater than or equal to 1 V p-p at J305 (standard HP 85623), or at U302 pin 3 with an oscilloscope (Option 103).

10.If the signal at U304 pin 13 is correct (see Figure 12-7), but there is a problem with the signals at A15J301, A155302, A155303, or A15J304, suspect U303 or U304 in the 10 MHz Distribution circuitry.

hp running

200 mV/div set: 0 000 v

000 : '1 dc

-250,000 ns	o,ooooo s	250.000 ns
	50.0 ns/div

1 f - 4 0 . 0 0 mV

Figure 12-6. 10 MHz Reference at A15J302

RF Section 12-21