General Troubleshooting Items; Nothing Works; Main Board - Thermo Scientific GENESYS 20 Service Manual

4.2
General
Troubleshooting
Items
1.

Nothing Works

Check:
a. Instrument is plugged in and there is power to the outlet.
b. Line cord is good.
c. Open fuse. This unit has two fuses. Both fuses must be good.
d. Check for a defective power switch.
e. Check primary power connection from switch to power
supply.
f. Disconnect power supply from main board and check voltages
(Ground is P3-4,5): +5V at P3-2,3; +12V at P3-1; -12V at P3-
6. Turn off power and reconnect to main board. Determine if
main board is loading the power supply.
g. Check fuse on power supply PC board. There is a single fuse
on the PC board. Test the fuse for continuity. This fuse is an
F2A, 250v. In case of failure the power supply must be
returned to a Power-One Authorized Service Center.
2.

Main board.

Check:
a. All cables assemblies connected.
b. +5v at J9-2, or C21+ (Ground is J9-5, 6 or C21-)
c. +12v at J9-1, or C22+
d. -12v at J9-7, or C24-
e. +8v at U30-1, or C27+
f. -8v at U29-2, or C26-
g. +5vA (Analog) at U28-1, or C23+
4 - 3
(No lights, no fan)
Troubleshooting