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Техника: iMac Intel 20" EMC 2210 Power Supply Output Voltage Test

Инструкция участника сообщества

Инструкция участника сообщества

Мы благодарны участнику нашего сообщества за составление этой инструкции. Она не редактируется сотрудниками iFixit.

  • Автор: Richdave
  • Времени уйдёт: 30 мин.
  • Сложность: Сложно

* The purpose of this guide is to provide detail on testing of the iMac PSU voltages.

  • Should only be attempted by those with experience working with a multimeter or voltmeter and LIVE equipment.
  • If you don't know how to use a meter to measure voltages then you should not proceed.

Шаг 1 iMac Intel 20" EMC 2210 Power Supply Output Voltage Test  ¶ 

After removing the front bezel,  you need to remove the 8ea 12mm T8 screws around the perimeter of the LCD Rotate the iMac so the TOP EDGE is facing you and GENTLY  lift the LCD up about 75mm (3in) and prop up the LCD with something NON CONDUCTIVE.

Шаг 1 iMac Intel 20" EMC 2210 Power Supply Output Voltage Test  ¶ 

  • After removing the front bezel, you need to remove the 8ea 12mm T8 screws around the perimeter of the LCD

  • Rotate the iMac so the TOP EDGE is facing you and GENTLY lift the LCD up about 75mm (3in) and prop up the LCD with something NON CONDUCTIVE.

  • Lifting the LCD in this way exposes the rear of the PSU to allow access to the PSU connector. When the imac is connected to the mains (even if switched OFF) there is MAINS VOLTAGE on this board

Шаг 2  ¶ 

REMEMBER - there is MAINS voltage on the PSU so use extreme caution Use the chart provided as a reference and test the various voltages with your meter being sure to restrict the probes to the 10 solder joints on the PSU connector shown within the BLUE rectangle.  Shorting any part of the PCB will almost certainly cause damage to the imac All voltage measurements are taken with PIN 1 as reference (Marked with the YELLOW square).  Pin 1 is marked on the board by a dot and is the right hand pin when viewed as shown in photos

Шаг 2  ¶ 

  • REMEMBER - there is MAINS voltage on the PSU so use extreme caution

  • Use the chart provided as a reference and test the various voltages with your meter being sure to restrict the probes to the 10 solder joints on the PSU connector shown within the BLUE rectangle. Shorting any part of the PCB will almost certainly cause damage to the imac

  • All voltage measurements are taken with PIN 1 as reference (Marked with the YELLOW square). Pin 1 is marked on the board by a dot and is the right hand pin when viewed as shown in photos

  • STANDBY means system connected to mains outlet but imac turned off - Diagnostic LED 1 will be illuminated on logic board

  • Pin 5 is the PSU enable line - Logic board pulls this line low (0V) to enable PSU (probably via a resistor)

  • Pin 4 voltage varies according to the PSU temperature and is inversely proportional to PSU temperature. Higher Temp = Lower Voltage. My measurement was taken at around **24 Deg Celsius.

  • Reassemble your iMac in reverse order. When lowering the LCD ensure you don't crimp or crush the LCD back-light cables