Re: X550jx black screen but cpu heating up
Provided 3.3v and no change.
Provided 3.3v and no change.
-
-
Re: X550jx black screen but cpu heating up
Put pq3002 and wait for oscilloscopeComment
-
Re: X550jx black screen but cpu heating up
Check xtal crystal oscillator 14mhz or 25mhz
If not ok then replace crystal
Signal sequence ends at pltrst#
It will not tell about BIOS
Check Chip select pin1 of PCH bios , frequency generated or not
If not then bios chip is dead
Pin1,2,5,6 these pins have signals , check via oscilloscope
If all ok then you have problem with gfx supply ,it should be present when CPU core and ram is ok
1.8v generated ?
in previous post you mentioned
VDD=0.9v ???Comment
-
Re: X550jx black screen but cpu heating up
Hmm interesting
3vs power good tied to high logic or 3.3v then it is ok 3.3
What is voltage on all pads of pq3002, check via boardview, list pad value
Voltage is still available at pq3002?
Suswarn# active only when any sus voltage is missing
Suswarn# is active and coming from PCH
Remove battery and check with adapter plugin only as if you see power sequence change with battery plugin DC modeComment
-
Re: X550jx black screen but cpu heating up
- No suswarn found in PCH boardview
- pq3002 3.3v voltage is only found while AC plugin in and 3 led (power+capslock+numlock) are lit but when it turns of and turns on again with 2 led then NO pq3002 3.3v voltage found. pq3002 has only 16mv
- same voltages with AC and same with battery testing sequenceLast edited by questore; 01-02-2021, 08:31 AM.Comment
-
Re: X550jx black screen but cpu heating up
Suswarn# is suspowerdnack# check in schematic power sequence diagram
Pq3002 all pads value name and voltage it is 3pin
Pq3002 3.3 at first but then zero
Sus voltage is missing, without sus voltage laptop will not show display and if you check schematic power sequence diagram 12v is an input to three sus switch ICS
What do you mean turn off then on?Comment
-
Re: X550jx black screen but cpu heating up
- Pq3002:
pin 1 16mV
pin 3 16mV
pin 2 GND 0V
When I plug in the AC connector (no battery connected)
then the laptop starts by itself immediately with 3 led constant lights (power+capslock+numlock) [at this point the Suspwrdnack is 3.3v]
then after 3 second the laptop shuts down and starts again by itself (2 led lights constant power+capslock) [at this point the suspwrdnack is 0v and stays that way]Comment
-
Re: X550jx black screen but cpu heating up
Did you get oscilloscope?
If yes check 1.05 PCH supply , 5v,3v,12vs all supplies
Should not have ripple , should be clear DC line signal
Do not connect battery until laptop rectified
With help of board view check
All 12vs points which are available on board
Experiment
You have PCH_susack# 3.3v and stable?
With jumper wire or tweezers create connection between suspwrdnack and pch_susack# and then
Start laptop , do not remove jumper wire
Check voltage at suspwrdnack with jumper wire still available
If voltage stable you have issue at 1.2vs supply which is required for display out
If voltage drops PCH is dead
ThanksComment
-
Re: X550jx black screen but cpu heating up
- Yes the oscilloscope arrived. I will check for ripples...
- Ok will check for 3.3 with jumper wire.
- 1.2vs can't be missing I think because my board is "type LDP" (link below) and does not have 1.2vs eletronics at all.
https://ae01.alicdn.com/kf/Hb447dceb...cM.jpg_q90.jpg
- Another idea: Can it be that I have flashed a "Type LVDS" BIOS and motherboard does not power on because it lacks 1.2vs?Last edited by questore; 01-04-2021, 08:40 AM.Comment
-
Re: X550jx black screen but cpu heating up
It can be simple bios issue yes
First check DC signals and clock at crystalComment
-
-
Re: X550jx black screen but cpu heating up
Flash good known normal biosComment
-
Re: X550jx black screen but cpu heating up
Done BIOS programming, no change
Comment
-
Re: X550jx black screen but cpu heating up
Bios is corrupted. Some parts are not writeable and always 0.
I order a new bios and hope for the best.
back when reprogrammed new chip.Comment
-
Re: X550jx black screen but cpu heating up
further: ch341a BIOS writer was faulty, BIOS is good. Ordered a new ch341a programmer.
Comment
-
Re: X550jx black screen but cpu heating up
Verified BIOS writen.
Now the status leds after powering on the laptop are:
power + numlock + capslock and they all steady lit (no flashing)
Cannot power off anymore by holding the power button. (written the previous bios and still the same)
with oscillator checked BIOS pin 1
shows 2 waving with multimeter after starting. (assuming CPU loads bios info)
No values are changed on any measured sequence points
Removed both +NVDD colis. No change
Problem persist.
WHAT NOW?? HELP!Comment
-
Hello everybody! Posting this in hopes somebody has some expertise that leads to a clear path of troubleshooting that saves me a lot of time!
My macbook has the flex cable problem, the one that prevents the screen turning on. Ive been dealing with this for the last 3 years. Last year it went dead and I managed to fix it following youtube tutorials. But my fix wasnt the best, the problem returned a month later. This week, it went dead again. I again tried to fix it.
This time the original cable broke too close to the screen, it can't be fixed without tearing the screen... -
Just had a customer bring in a M2 MBA A2681 that had had a screen replacement in April at another repairer. Since then, she has been getting intermittent kernel panics. It's an aftermarket screen, and of course it fails in diagnostics as the calibration hasn't been done. The error in the panic log is "No device added after powering on the rails".
It seems the original repairer has swapped the board and the screen to other MAC's, and said that it isn't a screen issue. From what I understand, by doing a quick search on Google, this is in fact a screen issue. The panic relates...07-31-2025, 08:37 PM -
Hi,
I have a iphone XS that came in for a screen replacement, the screen was badly cracked, and inside missing scues, on the back of the screen still the blue protector, the screen was a LCD. So we replaced the screen and all good, installed the screen and we noticed that pressing the screen with a bit of force but not excessive, the phone dies. After plugging the charger it turns back on, but again if you press it it dies. I open the phone again, and I can't see anything major, with the phone open, if I press on the logic board, battery, charging board, or even putting pressure on... -
Hello everyone, I’ve just been given a Samsung UE55JU6800K smart tv as it had white spots on the screen due to the led lenses falling off. After refitting them & putting the tv back together I thought it was a nice easy fix for a free bedroom tv , then I tried it before screwing the back into place. I realised that the right side of the screen was darker than the other side, I removed the screen again as I thought the backlights had failed but they are fine.
I put the screen back in place & turned it back on . The screen seemed to be ok again but different screens on the same... -
I'm currently trying to diagnose and fix my Vizio TV (Model M50-C1). I've tried a number of different basic solutions, but I'm trying to determine if my issue is currently a failing panel, T-Con board, or main board (or something else entirely) and whether or not it is worth my time to fix it. Details of the issue and what I've tried are below as well as why I think it is either a bad panel, T-Con board, or main board.
The Issue: The TV will be on and working fine but after the TV is on for ~5-10 minutes the screen will freeze (with sound continuing) until the TV reboots itself. While...
Comment