0 Volt PEX Rail on Zotac GTX 1080 8 GB OEM- No short help
Hello to all,
I'm struggling
with this card lol Zotac GTX 1080 OEM 8 GB
After checking there was a short circuit on the 1.8V from a capacitor and I had no voltage and now I have my 1.8V voltage.
Other problem I do not have the voltage PEX Rail 1Volts and measured value 48 Ohm seems correct.
Measured 3.3 V and 12 V and 5 V OK and 1.8 V OK to the coils
Missing Vcore between 0.8 V and 0.9 V and VEM 1.5 V (Rather normal because no 1 V PEX)
1 ) After checking the controller uP1728QBDDA (See photo Missing PEX) there is no signal EN = 0 V + PGOOD = 0 V + FB =0 V logic because EN not activated.
I replaced the chip 2 times always the same 0 V pex rail and well soldered.
2) I follow the EN signal which joins PEX_OVREG_PGOOD (See diagram) no VOLTAGE on PEX_OVREG_PGOOD and R693 + R982 +R709 but well 12V_F +3V3 Incoming
3) I measured then with the buck controller QFN5X5 VCORE U505 signal IN 2.2 Volts (Weird no?)
I also changed this controller always the same.
For the moment I don't know where I should look for an idea... What resistance should I measure according to you?
Many thanks to you in advance
I'm struggling
with this card lol Zotac GTX 1080 OEM 8 GB After checking there was a short circuit on the 1.8V from a capacitor and I had no voltage and now I have my 1.8V voltage.
Other problem I do not have the voltage PEX Rail 1Volts and measured value 48 Ohm seems correct.
Measured 3.3 V and 12 V and 5 V OK and 1.8 V OK to the coils
Missing Vcore between 0.8 V and 0.9 V and VEM 1.5 V (Rather normal because no 1 V PEX)
1 ) After checking the controller uP1728QBDDA (See photo Missing PEX) there is no signal EN = 0 V + PGOOD = 0 V + FB =0 V logic because EN not activated.
I replaced the chip 2 times always the same 0 V pex rail and well soldered.
2) I follow the EN signal which joins PEX_OVREG_PGOOD (See diagram) no VOLTAGE on PEX_OVREG_PGOOD and R693 + R982 +R709 but well 12V_F +3V3 Incoming
3) I measured then with the buck controller QFN5X5 VCORE U505 signal IN 2.2 Volts (Weird no?)
I also changed this controller always the same.
For the moment I don't know where I should look for an idea... What resistance should I measure according to you?
Many thanks to you in advance
Attached Files
