COLORFUL gtx760 graphics card irregular screen is black or frozen repair

Graphics card model: COLORFUL gtx760

Fault phenomenon: graphics card timing screen is black or frozen

Maintenance process:

A seven rainbow gtx760 graphics card, graphics card can be booting up into the system, but will be irregular screen is black or frozen.After screen is black or frozen,VCC is measured, but the core VCC, video memory VCC and PEX VCC are not available.During the process from normal to screen is black or frozen, PV pin of power monitoring chip ina3221 changed from 3.3V to 0V.PV pin is usually used as the en signal of the core VCC chip,PV pin becomes low, and VCC causes the en start signal of core VCC chip to be lowered and VCC is turned off.

COLORFUL gtx760 graphics card irregular screen is black or frozen repair Figure 1.
Ina3221 monitors 3-way 12V VCC and checks that VCC is normal.Ina3221 has an over-current Current protection, which may be caused by Short circuit.
There are three channels of 12V VCC in this display card, including one PCIe 12V and two 12V independent VCC. Measuring the 12V of these two independent VCC s, it is found that the diode value is only 150 and the normal value is 400.

Current heating test found that several MOSFET high temperature were removed, and the second pole value was 150. Continue to Current heating test, ina3221,high temperature, remove, and the second pole value is still 150.Current heating test found that the filter of 12V VCC and high temperature of Capacitor were removed, and the two poles of 12V were normal.Replace the new filter Capacitor, install the original ina3221 and MOSFET, and return to normal.Start booting up, no longer screen is black or frozen.