I give up when bend pcb or press power button all voltages present and goes away after 2 sec
tnx for trying help
ziko07
Senior Member
Last Activity: 04-13-2025, 12:10 PM
Joined: 06-05-2021
Location: Somewhere
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Your bin file is 128kB, ori on board is 64kB, its 25X05CL
In attachment my ori dump, the big one bios 16Mb servicer already tried 2-3 dumps...Leave a comment:
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I couldn't see on microscope, also tried ram in other slot
will double check...Leave a comment:
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Will check voltages tommorow, also will put your bios even servicer before me tried ,but strange when I bent, press board on ram connectors missing voltage comes again and after 2 sec goes away again. Like some bad solder or pcbLeave a comment:
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Resistance ACP/ACN is 0.004R, on probe direct 0.001R and drops to 0.000R
Here is image with coil resistance with GND
BQ chip write on it BQ25A......Leave a comment:
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I'm sure you get point that I meant 3v/5v
Too much syntax errors on my gsm tastature, sorryLeave a comment:
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Not seen suspicious resistance, I use to see current consumption bemch lab power but same probl with ori power adapter
when 35v present than board without battery tajes 450mA and there us oresent cou voltage 1.1v 2 ohases,1.0v, 1 2 to ran, fan spinning but after 3 sec all stops, i noticed if I bend pcb (i connected wire to 5v alw coil) than voltsge comes, like some bad soldering or maybe vias on pcbLeave a comment:
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LA-G07JP led power shortly and goes off
Hi, sch is from LA-G07DP but looks similiar. Problem is that 3/5 v ALW comes when bring power short (1-2 sec)
From image all marked GREEN is same, 1-2 sec has power
SPOK colmes 3v3 for short time
en2= 9v4, its normal and is stady voltage
en1= 3v3/5v short same as SPOK
LDO 3v/5V only present short as SPOK
Pin 11 of IC has stady 9.4v but LDO output also goes iff after 1-2 sec
EC_ON on pin112 comes also short time and goes low
Small ic drivers for 3 and 5v alw are SY8286A
Any help please?... -
VR_ON pin7 on ic is present...
Tnx but think will give up, first problem was no vc core and this ic was hot and make hole in it
power rail (VRM) mean when there will output 0.8v to cpu? Sorry I ask this butvmy primary job is car electronics, this is hobby moreLeave a comment:
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Only one from 5 was like this, other looks ok but when insert on pcb I lost 3v3 on VRM,_PWRGD at pin 8 on IC. It comes on 10k resistor, one side has 3v3, other side that goes to pin 8 on IC is zero voltage...Leave a comment:
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I got aliexpress ics, tried 2 no joy, even power ok pin thru series 10k resistor has 3v3 on one side only when install IC
probably fake chips, I also desoldered coils to mcu...
see age "new" ic from package opened...Leave a comment:
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hp elitebook 2530p strange problem
Hi, I have this laptop , battery charge ok, also when powered ON and insert charger battery charge ok, but problem is IF charger is inserted and no matter if removed after that when switch off laptop or going hibernate when lid closed, in that case cannot start again when pressing power button, unless I reinsert battery.
When operate on battery only no problem at all.
Also, if remove battery and use charger only no way to start laptop ( I have second same model and it works on charger only fine).
There is sensor touch button (see image) when pressed on good laptop ,laptop... -
That 2x 0.9v and 1.8v was probably accidently and then fan spining and mcu geting hot, after a while no mpore +1.8valw and nbo 1.2v no 0.9v, only present 3.3/5v alwLeave a comment:
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Lenovo IdeaPad 3 NM-C821 Rev 1.0
Hi, I have thislaptop no POST, no image,no capslock ON,when connect charger, battery charging power led ON ,but power button led flashing constantly
I tried tested bios but still same problem, all voltahe looks present, 3v3/5v/2x0.9v/1.2v, 1.8v on bios chip even fan spinning, mcu is like working hot, it drass 390mA without battery connected, 1.2A with battery charging
Any tips? -
As I see both 1v0 and 1v8 goes to gpu maybe there is problem but once was all voltage ok,that's strange to meLeave a comment:
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r9 280 no picture and shorts coils
Hi, I have this graphic card no image, when power on fans spin but I measured and has only +12v from PCI and power 12v both connectors. also +5v linear present, 3v3 from PCI present. MCU is cold, then I I tried measure again and on coils, 1.5V,1v0, 1.8v, on mcu 0.8v all present and mcu slictly warmed up. After that I tried to put on motherboard and still no image, but now also all those voiltages missing again , only +12v present and 5v
Then I measured (see image in red colour) and all those coisl has dead shorts, 0 ohm. I thing when first measuring voltage (I didnt check resistance) was... -
There was short on gate of both FETs, when removed IC short gone, must find that IC to test, hope not processor dead.
0.6V that shows on cpu coils actually not have PWM on one side of coil at all. Now I lift one side of coil, resistance from mcu core VDD to GND is only 5R8, not know is it normal or also processor gone
TnxLeave a comment:
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i found what going mad hot , its IC ISL95831 PWM controller for CPU core, but cpu core voltage 0.6v present, or maybe its low voltage for cpu??...
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No liquid damage, just died, here is image with voltage and resistance on power coils. 5v alw and 3v3 have resistance more then 5k and both power draive ~90mA when bring external desired voltage on coils...
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Asus K53SD restart,no picture
Hi, I have this laptop when insert charger battery charging is on andcwhen press ON button,power led lights 1-2 sec and goes off. I opened and reset bios,after that power ked is on and 2,3 more leds is on but after 6sec restart and loops constantly same (only charger insert,without press power button). As I see no more battery charging led is on. It draws 370-450mA. All power present, on cpu cire 0.6v only missing power is gfx core.
any help?
Pcb is rev 6.0, I put bios 5,1 and after that found here 6.0 but no changes on laptop behaviour
Tnx
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