Acer v5-471 no display

[String2016]

I need help on this acer v5-471 48.4TU05.04M laptop, at first laptop came here dead shorted PU4401 so replaced it and laptop turns on now, but the problem no display, already tried replacing ram with good one still same and external still no display,upon check voltages there in 3.3v and 5v and 1.5v on and vcore 1v, but there is no PLTRST# and DRAMRST#. Ive notice also PU4201 ISL95836 chip is very hot, upon checking pins pin 9 VR ON have 3.3v pin19 PGOOD 3.3V and PIN36 PGOODG 3.3V, anyone can help on this please

[String2016]

Re: Acer v5-471 no display

anyone can help on this please

[stingerchamp]

Re: Acer v5-471 no display

Share schematic

If your ic is ram ic check Suson,mainon signal at ic and ton voltage which is connected to PCH in some motherboard

pltrst# is a signal coming from PCH,it is also indicate that your PCH is active if you get this signal then we can get slp-s5,S4 and S3# from PCH at coils and will generate state voltage.

Check pltrst# signal going at which locations

Or share schematic I guide

[String2016]

Re: Acer v5-471 no display

thank you for the response, here is the schematic

[stingerchamp]

Re: Acer v5-471 no display

Ok now we have pltrst# signal after we get

So_power_good which comes after we get slp_s3#

First check these then check imvp_,, power good

Use full signal name and where did you check it
And share where did you check plt_rst# signal

[String2016]

Re: Acer v5-471 no display

i check the pltrst# on wifi slot pin22 there is no voltage there, also check dramrst# on pin30 on ram slot there is no voltage there, noticed PU4201 ic is getting hot

[stingerchamp]

Re: Acer v5-471 no display

At page 36 you have small circuit for plt_rst#
Q3601


Check r3616 getting signal there

At pin 37 of LAN RT you have plt_rst#

Check voltage at r1908 resistor

S0_PWR_GOOD as mentioned in previous post check it first then check imvp_pwgood because both are connected to and gate logic to generate sys_powerok to pch


For dramrst signal you have at page 37 q3703 , check c3703 for short
Check dramrst_cntrl_pch available at gate

[mcplslg123]

Re: Acer v5-471 no display

if you dont have dramrst#, then why focus on pltrst#?? You are far from it. Pltrst# is one of the last signals. Concentrate on your RAM IC and do check Q3703 as suggested. You can even remove Q3703 and power up the mb and see if dramrst# rises.

[String2016]

Re: Acer v5-471 no display

Thanks for the response, i cannot find he Q3703 located on board

[String2016]

Re: Acer v5-471 no display

I found q3703 s=3.3v both drain and gate 1.5v c3703= other side have 3.3v but other side have 0v

[mcplslg123]

Re: Acer v5-471 no display

Q3703 measurements proves its working and dramrst# is present. Are you sure you measured on pin30 of dimm slot and there is no voltage?? It seems very unlikely. Re-measure it if possible.

[String2016]

Re: Acer v5-471 no display

still no dramrst# on pin 30 of the ramslot

[mcplslg123]

Re: Acer v5-471 no display

Check continuity between Q3703 drain pin to pin30 of ram slot. Are you counting the pin correctly??

[String2016]

Re: Acer v5-471 no display

I double check it from dran of q3703 to pin 30 0f ramslot there is no beeping

[emestee]

Re: Acer v5-471 no display

I double check it from dran of q3703 to pin 30 0f ramslot there is no beeping

Take a looking glass and a good light source and look at the back of the DRAM slot. May be a cold joint or mechanical damage hiding over there.

[String2016]

Re: Acer v5-471 no display

already tried that, also tried resolder each pin still no DRAMRst# on pin 30

[stingerchamp]

Re: Acer v5-471 no display

If at drain you are getting 1.5Vol then q3703 is working

and it is connected to pin 30 of reset signal at ram slot

What is voltage exact value at

Pins ,1 ,199,126 ,200,202, 203,204 , 75 ,30

Remember we need 1.5voltage at pin 30 not 3.3v