WSM6 Manual
Document Ref: UM-8270-000
Issue: A Rev 0
Section 8
96
8.5.1.1
Pre-amplifier First Stage Output
1.
This waveform is monitored at TP9 on the lower board. Refer to Figure 8-5.
2.
Both input and output signals are shown. The input starting at 0ms and the reply starting at
approximately 30ms.
3.
The signals are on a level 2.5V and >2V in amplitude.
4.
If the input signal is not present, then possibly U15 or one of both of the long tailed pairs (Q7
and Q8) are faulty.
NOTE
It is possible the CPU board or connector SKT2 and 4 (or mating connector) may be
faulty; change the upper board and observe the result. A definitive diagnosis is not possible
at this stage.
Figure 8-5 – Pre-Amp 1
st
Stage Waveform
October 2011