Tektronix TG8000 Service Manual

HD3G7 module troubleshooting
Check the multiple frame
rates
The mainframe p
rovides three frame pulses which are used to set the module
timing relative to the rest of the instrument. Different frame pulses are us ed,
depending on the signal format the instrument is set for. Use this p rocedure to
investigate problems in that circuitry.
1. Connect the HD3G7 module outputs to a w aveform monitor.
2. Apply power to the TG8000 mainframe.
3. Recall the F
actory Default preset as follows:
a. Press the MODULE button until TG8000 appears.
b. Press Enter button to select Preset.
c. Press the up (▲)ordown(▼) arrow button to select RECALL.
d. Press the left (◄)orright(►) arrow button to select Factory Default.
e. Press the ENTER button to reset the instrument to the factory default
settings.
f. Press the BACK button to r eturn the TG8000 main menu.
4. Ver i f
y that both HD3G7 module outputs provide a 59.94, 1080p format, 75%
color bar signal.
5. Check
the DDS1:Phase lock status, as described in the Module Diagnostics.
(See page 11-15, Check the module diagnostics.).
6. Chan
ge the HD3G7 format to 60 Hz:
a. Press the MODULE button t o se l ect t he HD3G7 module.
b. Press the FORMAT button to enter the HD3G7 format menu.
c. Press the left (◄)orright(►) arrow button to select 1080 60p.
7. Check the DDS1:Phase lock status, as described in the Module Diagnostics.
(See page 11-15, Check the module diagnostics.).
8. Change the HD3G7 format to 50 Hz:
a. Press the MODULE button t o se l ect t he HD3G7 module.
b. Press the FORMAT button to enter the HD3G7 format menu.
c. Press the left (◄)orright(
►) arrow button to select 1080 50p.
9. Check the DDS1:Phase lock status, as described in the Module Diagnostics.
(See page 11-15, Check the module diagnostics.).
If one of the formats (59.94 Hz, 50 Hz, or 60 Hz) works correctly, but the other
one does not, the mainframe sync pulse may be missing. Perform the Swap
modules procedure, below, to determine the source of the problem.
TG8000 Multiformat Test Signal Generator Service Manual 11–19

Tektronix TG8000 Specifications

General

Brand	Tektronix
Model	TG8000
Category	Portable Generator
Language	English