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Old 12-27-2019, 10:08 AM   #20
jasko_jacker
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Join Date: Oct 2014
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Default Re: Dell INSPIRION 15 7567 BSOD

Quote:
Originally Posted by jasko_jacker View Post
I have traced the component under check and after cleaning the card the previous values are wrong.
(LA-D991P schematic is unvailable)
The burnerd inductor receives the 19V and sends it to a double mosfet (siz980dt). This mosfet is driven by an ampec (APW8828).
I expected a short on S1 / D2 but the Ohm value is high (G1 and G2 -> 0V with motherboard ON).
What I would like to understand is if the circuit of this board page 73 LA-D751P schematic is similar. (it seems that on the alienware LA-D751P both the ram and the GPU are powered by the same 1.35VS_VGAP-> 1.35VS_VGA line but I could be wrong)
However it seems that PL901 is the voltage for VRAM.
Following the track that goes under one of the ram and which has an Ohm value of 0.50 compared to PL901 (therefore they are connected) I do not detect any short compared to GND. I don't know if it is appropriate to inject the 1.35V on PL901.
I soldered a new dual mosfet , changed the burnt coil and replace the inductor. Now at the end of PL901 there is 1.4V . all that remains is to replace the capacitor (19V to GND) with an appropriate value, which value do you recommend?
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File Type: jpg LA_D993P_GPU_VRAM_SOLVED.jpg (696.3 KB, 94 views)
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