Tektronix DSA8200 Series, Service Manual

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Troubleshooting
DSA8200 Digital Serial Analyzer and Modules Service Manual
4--85
If the mains power is on, a red light (see Figure 4--49 for its location) is visible
through the right side of the instrument.
Mains power-on and over current LEDs are
near the center of the power supply. A red
glow from them is visible while looking
through the side of the instrument.
Figure 4--49: Location of power-on and over current LEDs
If the instrument thinks power is on, a red light (see Figure 4--49) means that
there is an over current condition.
If the on/standby pin (pin C1 of P201 on the rear power distribution board or pin
B162 on the riser board) is low, the instrument thinks power is on.
Remove boards one at a time to locate a fault (the display, floppy, acquisition
board, front [analog supply to acquisition board] and rear power distribution
boards, the ATX board, and the riser board). If you remove the ATX board, you
must jumper the debug power-on pins (see Figure 4--50). The PPC board and the
rear power distribution board are required for power to come up.
If removing the boards did not find the problem, replace the power supply.
Isolating to a Board if
Power Will Not Come Up