Sapphire RX 480 - 8GB no power - 0 volts to +VDC
Hello to all =D
I would like to start this card again for my little brother.
Symptoms :
No power on , no rgb led , black screen , no rotating fan.
What I found before disassembly a 22uF capacitor on the +VDDCI line was loose. Before powering up and checking if the component was missing, the capacitor was replaced.
Then powering up
+12V ok
+5 Volts ok
+1.5 V ok
+ 0.90 ok
What I found abnormal :
-No 0 Volt on the +VDDC line of the CPU, value found 0 Ohm, diode mode 0mv and finally 0 Volts on the whole phase row (Which can be seen in grey metal capsules and I circled in yellow.
The +VDDC seems to be controlled by the power regulator if I am not mistaken.
What I did:
1) Removed the synchronous buck gate (IR3553 chip) driver phase 6 and phase 1 and still 0ohm and diode mode 0.01 mV on the phases
2) Removed then one by one the 4C10N mosfets but before removing everything I found 12 Volts drain on each but still 0 Ohm on the phases.
Can you look at the diagram I am attaching on page 15 of 26 all the phase lines and the +vddc line and I am attaching the other photos for your convenience.
and the Buck controller datasheet
To tell the truth, I may be going the wrong way, no?
Thank you very much in advance team =D =D
Hello to all =D
I would like to start this card again for my little brother.
Symptoms :
No power on , no rgb led , black screen , no rotating fan.
What I found before disassembly a 22uF capacitor on the +VDDCI line was loose. Before powering up and checking if the component was missing, the capacitor was replaced.
Then powering up
+12V ok
+5 Volts ok
+1.5 V ok
+ 0.90 ok
What I found abnormal :
-No 0 Volt on the +VDDC line of the CPU, value found 0 Ohm, diode mode 0mv and finally 0 Volts on the whole phase row (Which can be seen in grey metal capsules and I circled in yellow.
The +VDDC seems to be controlled by the power regulator if I am not mistaken.
What I did:
1) Removed the synchronous buck gate (IR3553 chip) driver phase 6 and phase 1 and still 0ohm and diode mode 0.01 mV on the phases
2) Removed then one by one the 4C10N mosfets but before removing everything I found 12 Volts drain on each but still 0 Ohm on the phases.
Can you look at the diagram I am attaching on page 15 of 26 all the phase lines and the +vddc line and I am attaching the other photos for your convenience.
and the Buck controller datasheet
To tell the truth, I may be going the wrong way, no?
Thank you very much in advance team =D =D
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