powersoft X4 - Dante Networking

INDEX
27
X4 | SERVICE MANUAL
(Fig. 25)
Remove the Varistor assembly.
With a MultiMeter set to OHM, check the resistance
between the two points indicated on (Fig. 25)
R= 0Ω: short circuit, replace PSU
R= 1K: OK, resume testing procedures.
Ω
(Fig. 26)
(Fig. 28)
(Fig. 27)
(Fig. 29)
Focusing the attention on U29 and U27, as portrayed on
(Fig. 26), check the resistance between pins 4-7 and 1-7.
(Fig 27)
IC PIN Resistance
U29 1-7 5K (approx.)
U27 4-7 3K (approx.)
In case of any short, replace the board.
Focusing the attention on U51 and U52, as portrayed on
(Fig. 28), check the resistance between pins 4-7 and 1-7.
(Fig 29)
IC PIN Resistance
U51 1-7 12K (approx.)
U52 4-7 500 (approx.)
In case of any short, replace the board.