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 more
ziko07
Senior Member
Last Activity: 11-14-2024, 08:17 AM
Joined: 06-05-2021
Location: Somewhere
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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 -
Re: Asus strix gtx980
Strange, 2 coils for memory chips has dead short, zero Ohms but when inject 0.8V 5A no any component get hot...Leave a comment:
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Asus strix gtx980
Hi I had this card not work, not found short on high side fets,gpu core 0v8 present but not have pover 2 coils that are in same row withbthis,not know if they are for memory power or else. As I see fets gate are driving by uP1631p. 5v vcc is present on driver, 1v2 enqble pin also present but no pulses to gates.
Any info or datasheet for driver?
Tnx
P.S. off topic I also repaired sapphire, shorted IR3553M. I replaced but that phase not work, I found also not pulse from driver. Other IR3553M has pulse IN. But later 2 more IR3553M gone and there is IN...Last edited by ziko07; 11-14-2023, 01:08 PM. -
Re: La-7912p second board
PCH has no cooler but getting quickly pretty hotLeave a comment:
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Re: La-7912p second board
Hi, board power on ok but after 30-50 seconds all 3 usb stop working. On external keyboard led goes off and I see when I put freeze spray at pch keyboard leds works ok but shortly and goes off again
Is it pch damaged?
When put external power without battery and lcd it takes 28mA,isn't that much?Last edited by ziko07; 10-04-2023, 12:19 PM.Leave a comment:
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La-7912p second board
Hi
I openet new topic becouse now diferent problem to this board
Board power On , and without Ram module has CPU_CORE 1.2V on both phases
But when insert Ram memory in slot then board has power On with cpu_core and restart and once again core is 1.20v and then drop and no more cpu_core present.
At this point I can see also on RAM that DIMM_DRAMRST# is missing (but think this should not affect cpu_core missing)
All voltage is OK on RAM except [pin-30]
Like something other couse problem,but this happend only when insert memory
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Re: La-7912p
update: I get other ddr3 memory. put and finaly 0.45v on gfx and picture comes
now boart takes 08-0.9A before 0.65A
second board with new ram, it comes and goes off twice, in that time cpu core present and lost, "without ram memory cpu_core is present"
VR_ON signal is present
Any sugestion?
both board has same flash in both flash memory
now will play with second board
Tnx to allLast edited by ziko07; 09-18-2023, 06:55 AM.Leave a comment:
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Re: La-7912p
I saw on YouTube when missing gfx they put external buck convertor. Can I try,what voltage exactly need?
TnxLeave a comment:
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Re: La-7912p
Tried with screen,hdd,hdmi and not work, no image
Also when insert usb keyboard caps lock is not light
On DIMM_DRAMRST# has 1.5v, shouldn't be half voltage 0.75v ?Leave a comment:
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