acer la-e921p dramrst missing but vcccore present!?

myth77

Badcaps Veteran

Join Date: Feb 2017

Posts: 380

Country: Croatia
#1

acer la-e921p dramrst missing but vcccore present!?

01-23-2023, 01:08 PM

This laptop came with problem turning on, no picture. PU1401 was getting hot and shorted on NVVDDS_BST1 line. After replacing all was ok on first...i have every voltage, even vcccore, but no picture...then i noticed that dramrst was only 0.07 Vol. First, i dont understand how it is possible to have vcccore without dramrst!? tried with two different bios but the same, signal DDR_DRAMRST# only rises to 0,07V. plt_rst is ok. I tried three different ram sticks. Any ideas?

boardview and schmetic attached
Attached Files

la-921p.rar (4.71 MB, 30 views)

Last edited by myth77; 01-23-2023, 01:11 PM.
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mcplslg123

Badcaps Legend

Join Date: Jun 2015

Posts: 7262

Country: india
#2

01-23-2023, 11:10 PM

Re: acer la-e921p dramrst missing but vcccore present!?

It is certainly possible to have vcccore with dramrst# pulled low-rather thats the norm. You wont get GFXcore when dramrst# is pulled low for sure. Since you have tried bios(assuming me cleaned),it may be cpu itself. DramRST# is pulled high or low by cpu.You can try checking the cpu's requirements are all fulfilled or not.
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acer la-e921p dramrst missing but vcccore present!?

acer la-e921p dramrst missing but vcccore present!?

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