Troubleshooting - Bosch TCA640 Series Repair Instruction

7.5

Troubleshooting

Danger!
If tests have to be conducted while the
appliance is live, ALWAYS use a residual-
current-operated circuit-breaker!
7.5.1 Tools:
►
Torx-screwdriver T10
►
Electric multimeter
►
Circuit diagram
7.5.2 Appliance does not switch on
Fault description:
The display (display or symbol) on the appliance does not come on.
Possible faults:
1. No power supply
2. No voltage at the mains input of the appliance
3. No voltage at the mains switch
4. No voltage at the power module input
5. No voltage at the power module output to transformer
6. No voltage at the power module input from transformer
7. No voltage at the power module output to logic module
8. No voltage at the logic module input
58300000120060_ARA_en_c.doc – 18.09.09
Troubleshooting:
1. Check power supply (220–240 VAC)
If there is no electrical meter available, temporarily insert and operate
another electrical device on the same socket.
→
►
No power supply Have electrical installation checked.
►
Power supply available
2. Check voltage at mains input (220–240 VAC)
To do this, open the appliance. Using the Torx T10 screwdriver, un-
screw all rear panel screws and remove the rear panel.
Check voltage at the mains input (terminal on noise filter).
→
►
No power supply defective power cord
►
Power supply available
3. Check voltage at mains switch input (220–240 VAC)
Measure voltage on the neutral conductor of the feed-in (terminal on
noise filter) and on the main switch input.
→
►
No power supply defective mains filter
►
Power supply available
4. Check voltage at mains switch output (220–240 VAC)
Set mains switch to "On".
Check voltage between plugs F1 and F2 on the power mudule.
→
►
No voltage defective main switch
►
Power supply available
→
see Point 2
→
see Point 3
→
see Point 4
→
see Point 5
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