Hi, have a HP workstation Z2 Mini 4G for repair with CPU vcore missing.
The resistance at the output of CPU vcore coils, is less than one ohm so I think CPU could be damaged, but no mosfet are damaged.
It mounts an i7 8th gen, and have only i5 7th gen for test, but I think it is not compatible.
Without CPU in the socket there is no short, but there is no vcore voltag, and it emits a beep like no detecting ram.
The controller chip for cpu vcore is a MP2949A, and has no enable voltage at pin 37.
I wonder which circuit generates this enable...
Thank you to the guys at HEGE supporting Badcaps [ HEGE ] [ HEGE DEX Chart ]
Announcement
Collapse
No announcement yet.
User Profile
Collapse
-
CPU vcore missing in HP workstation Z2 Mini 4G
-
Hi, have some interesting news.
laptop has been working for a few hours and can confirm that voltage on vcore is too much higher than it should be.
In bios setup screen vcore was 0.8 volts and in windows login screen it was 0.6 volts during that few hours.
So I think it should be a problem with a resistor o capacitor from the feedback circuit.
I have tested some resistor but seems to be good all of them, but without schematic is very difficult to follow the circuit.
Could be an internal cpu voltage sensor problem?
-
Hi, I have replaced the output mosfets and tantalum capacitor, and still the same. I have not replacement for coils now.
Booting a BlackArch linux iso via Ventoy, it still crashes, but looking at the screen error messages seems that cpu is damaged.
I don't know what messages can say, so I hope someone in the forum can read that messages in the photo attached, and tell what it is about.
Thanks in advance.
[ATTACH=JSON]{"data-align":"none","data-size":"medium","data-attachmentid":3231294}[/ATTA...
Leave a comment:
-
Hi [B][URL="https://www.badcaps.net/member/149220-mcplslg123"]mcplslg123[/URL], [/B]thanks for your advice, I know that intel haswell and braswell have an internal regulator for vcore, didn't know that 10th and 11th have the same.
The coils are rather unusual, 240 uH. are not frequently used, perhaps there are some in my donor boards.
It has only one tantalum capacitor, (330 uF) I will replace it and see if there are room in the board for another one.
There is another coil near the two of vcore tha seems the GFXCORE coil, but 1.8...
Leave a comment:
-
Hi, I have replaced the Richtek RT3612EB today with a new one, and still crashes in windows and Linux, but ms-dos works well.
Still cpu vcore is 1.6 volts, sometimes is 1.8 volts.
I will tray to reduce that voltage tweaking the resistors of feedback circuit, but it is not easy working only with the datasheet.
Do you know if ThrottleStop program or other similar can be run before windows starts?...
Leave a comment:
-
Hi Tony, seems that bios works, at least like the original one. It will be very estrange that different data on bios behaves the same.
Where did you get the new data for the bios?
Try to boot without any memory in slots and compare. It will be great if you have a lab power supply and could see the current consumption.
By the way, how much voltage do you have in cpu vcore?
You can test diode mode readings, as long as it seems to have cpu vcore, and cpu gets warm....
Leave a comment:
-
Yes, it's like testing a diode. Testing chips is almost the same, but the test have to be done between every pin of the chip and ground.
Red probe from multimeter has to be connected to ground, (ie. negative pole from dc jack or any usb)
Here you have a picture from the chip. [ATTACH=JSON]{"data-align":"none","data-size":"full","data-attachmentid":3225988}[/ATTACH]...
Leave a comment:
-
Hi tony, I know some people use a Raspberry Pi with the flasrom program for flashing bios, but the cheapest way is to buy a CH341A + SOIC8 clip + adapter.
You should use a multi-meter in diode scale with red probe to gnd and black probe to the pins of the chip.
Most of the pins readings will be in the range of .500 to .600.
Only pins from 6 to 22 are relevant for me. I've attached a screenshot of a board-view from other model for reference.
This chip is located in the same side of the board as the 3 pins smd....
Leave a comment:
-
[QUOTE=tony.knors@live.com;n3219606]That's the issue .. I have the part but not the location on the PCB ! The part is a 3 PIN SMD with reference X32A. I added a picture./QUOTE]
It seems a little mosfet, but could be a bipolar transistor or a double diode. I will tray to locate it in the board and send you a photo of the area it is located.[QUOTE=tony.knors@live.com;n3219606]That's the issue .. I have the part but not the location on the PCB ! The part is a 3 PIN SMD with reference X32A. I added a picture./QUOTE]
It seems a little mosfet, but could be a bipolar transistor
Leave a comment:
-
I think the problem with this board is the cpu vcore, being a little higher. There are two phases circuit in the cpu vcore, having 1.6 volts at the output of that circuit.
With the oscilloscope I can measure about 400khz pulses at the input of both coils, but sometimes one of phases doesn't work. (pulses are missing randomly in that phase)
The chip that controls the mosfets of that circuit is a Richtek RT3612EB.
I have downloaded the datasheet of that chip, but it is a nightmare the way it works. I will tray to locate a similar board with this Richtek chip...
Leave a comment:
-
DAG7ELMBAC0 motherboard windows crashes.
Hello everyone, have a HP laptop with DAG7ELMBAC0 motherboard that crashes when booting windows.
With a pen-drive with Linux or hiren's is the same, only with ms-dos programs run without problems.
It passes all ms-dos memory tests, and also all Pccheck 6.1 tests. (some tests not run properly because are not designed for new CPU)
Same with other bios and other ddr4 module.
I have disconnected the vcore rails from GPU in order to test with only internal Intel graphics, to no avail.
In the past I've had the same problem, but due to corrosion near kbc chip,...
-
Schematic Acer aio 19476-1
Hi, need schematic for Acer aio, motherboard DELPHI_215I 19476-1.
Thanks in advance.
-
-
Bios for Primux iox All in One 24I3FW
Hi, need a bios dump for a Primux iox All in One 24I3FW.
Motherboard: IP3_GA215_MB_V30_20190402A
The initial problem was a shortcircuit (cero ohms) in the 5v pwm coil output.
(ceramic capacitor shorted)
Probably bios get corrupted before short.
Original bios dump attached....
No activity results to display
Show More
Leave a comment: