HP 3562A Service Manual page 136

ADJ U STME NTS
Pressing the beeper key toggles the beeper between on and off.
It does not matter whether the beeper is turned on or off as long
as the keys are pressed in the order spec ified. If beeper comma nds
have been activated, the instrument must be reset before it can
make measurements. Th is is requ ired because the beeper com­
mands configure internal circu its for special tests which do not
allow accurate measurements to be made.
If the circuit is bad ly out of adj ustment the signal may appear as a triangle waveform
Figure 3-4 ADC board component locator (A32)
with either the upper or lower corners extending outward as spikes as shown in figure
The fol lowing adjustments shou ld red uce the spikes to form a regular triangle
waveshape and then flatten the triangle waveform into a "straight" line as shown in figure
3-8. The noise remain ing after adjustment appears in varying amou nts on most boards.
3-5 .
8. Adj ust A32 R408 to remove sharp spikes in the scope waveform as shown in figure
3-6. These spikes may protrude up or down, depending on which way the adj ustment
is off.
9. Adjust A32R422 to fl atten the triangle signal at A32TP401 (shown out of adjustment
in figure 3-7).
3-8
NOTE
A22
Board
Location
Key
TP400
R422 TP401
MO D E L 3562
) 200
R408