Address
304 North Cardinal
St. Dorchester Center, MA 02124
Work Hours
Monday to Friday: 7AM - 7PM
Weekend: 10AM - 5PM
Address
304 North Cardinal
St. Dorchester Center, MA 02124
Work Hours
Monday to Friday: 7AM - 7PM
Weekend: 10AM - 5PM
IQ3X0MS repair without display
IQ3X0MS has no display. After replacing R18, VCC 3.3 is generated and vccio VCC comes out.
Machine model: IQ3X0MS motherboard
Fault phenomenon: no display
Maintenance process: connect an IQ3X0MS motherboard, measure the circuit to ground Diode value is normal, power on, no display, the measurement of 3V, 5V, 12V is normal, vccio measurement does not have VCC.
IQ3X0MS repair without display Figure 1.
IQ3X0MS repair without display Figure 2.
IQ3X0MS repair without display Figure 3.
Looking for the definition of vccio VCC chip pin, it is found that 10 pin en does not have EN, and en EN is pulled up by + VCC 3.3. The measured VCC 3.3 VCC is 0, and the control pole g of n-channel MOSFET generated by VCC 3.3 is not VCC.
IQ3X0MS repair without display Figure 4.
IQ3X0MS repair without display Figure 5.
IQ3X0MS repair without display Figure 6.
The g-pole is controlled by a composite MOS Switch tube, and the Q1 composite MOS Switch tube is normal.However, D2 is VCC on the low side. After measurement, it was found that R18 pull-up resistance Oxygenation was found. After replacement, VCC 3.3 was generated, vccio VCC came out, and the maintenance was completed.
IQ3X0MS repair without display Figure 7.