COLORFUL B150M-K motherboard no booting does not show repair

COLORFUL B150M-K motherboard no booting does not show repair

Main board number: colorful B150M-K V20 (all-solid-state version)

COLORFUL B150M-K motherboard no booting does not show repair figure 1.

Malfunction phenomenon:

High probability fault point and fault phenomenon

1. standby no power on is available.
2.VCC is missing (memory is unreadable or auto power off)
3.VCC is complete, reset, but not displayed.

Maintenance process:

First, there is a standby no power on

1. I/O model: IT8613E

COLORFUL B150M-K motherboard no booting does not show repair figure 2.

switch sequence, the first common failing point: RSMRSt 43 pin without VCC, the measuring line is connected with a resistor.

COLORFUL B150M-K motherboard no booting does not show repair figure 3.

The resistance diode value on the board is 1 ohm, and the 43 pin 0V of the failed board IO can be used normally by replacing the resistance of 0-100 ohms, so short-circuit must not be used.

2、no power on
(1)MOSFET in the red circle of Area 1 in the first picture.

COLORFUL B150M-K motherboard no booting does not show repair figure 4.

If MOSFET is in bad working condition,VCC may be normal, but it doesn’t run code.

(2)no power on, first troubleshoot the BIOS program and check whether the ME module VCC 1V is normal.

Note that if the standby conditions are met and S3 is not sent from the bridge, the IO corresponding to pin bit will be provoked first, and then the judgment will be made.

Second, the lack of VCC
1. lack of memory VCC,

VCC starts normally, which basically means that up1566p is damaged. Most of EN sent by the bridge has not arrived, which basically means that the bridge is broken. Here is the test pin of up1566p.

COLORFUL B150M-K motherboard no booting does not show repair figure 5.

2. The missing VCC is shown below

One is similar to PCH_1.8V, but it is 0.9V on the normal board.

COLORFUL B150M-K motherboard no booting does not show repair figure 6.

Chip screen printing: LA1A is an operational amplifier APL5611.

COLORFUL B150M-K motherboard no booting does not show repair figure 7.

The fault phenomenon is that MOSFET lacks this 0.9v, and the operational amplifier 1 pin EN 0v. When the operational amplifier EN is switched on, it will become high immediately.

3. The front-side bus VCC 0.9V is missing

COLORFUL B150M-K motherboard no booting does not show repair figure 8.

Basically, it’s caused by two MOSFET’ s in area 2 in the first picture. If it’s in the wrong working state, it will be replaced, mostly in the back.TriodeDamaged.

4. The upper CPU has no CPU main VCC, and the bare board can measure the VCC, and the PWM chip is RT3606B.

COLORFUL B150M-K motherboard no booting does not show repair figure 9.
The 43 pin of this board is a chip connected with a 500K resistor, so it is OK to replace it with 480K.

3. The VCC is normal, with no display.

1. CPU VCC unstable

The oscilloscope saw the frequently changing waveform. The oscilloscope probe Stop at, the lower tube of the front-end bus VCC, was found to be G-level control VCC unstable, and the root cause was one of the two VCC’ s defects in the label 2 area.

1. The full version of VCC is normal, and there is no display.

It is also the PWM chip RT3606B that controls the pin of the upper and lower MOSFET of the integrated display. This resistor is connected externally, and it can be changed to a little smaller.