thank you mcplslg123 for confirming that I shall give up reparing this dead laptop!
I do not have the skills to replace the CPU.
bert-bert
Member
Last Activity: 04-19-2025, 08:17 AM
Joined: 10-18-2024
Location: Linz, Upper Austria
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And just a moment ago I also unsoldered PJ502 and PJ510. Every part of these wires is shorted to ground with below 1 Ohm. It must have been an error that I just measured 1,5 Ohm. Now I measure below 1 Ohm. Just the voltage regulator works at 3.4V. There must have been an overvoltage, and now everything is shorted, don't you think so?
Please confirm that I shall give up working on this dead board.Leave a comment:
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I unsoldered PJ402. And the voltage regulator is not shorted. It delivers 3.4V.
I also unsoldered J7 for the PCH. And the PCH is shorted to ground with 0R5. Is this ok, or is this defective? Is this a defective CPU? I'll give up on repairing this board then.
The other side of J7 is shorted to ground with 1R5. I can investigate further there.Leave a comment:
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thank you!
To me it looks like remains of flux from manufacturing. Is this possible? There's PU1402 on the other side of the board there where there is this dirt. But PU1402 looks nice.
Seems PU401 and PL401 are for the 3.3V rail. I guess I shall unsolder PJ402, to see if the short is on the upper or on the lower side of PJ402. And if the short is in PU401, I probably shall replace PU401, and if the short is not in PU401 it will get difficult.
I'll unsolder PJ402.Leave a comment:
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dead Lenovo ideapad 320-15IKB
Hello,
I have a Lenovo ideapad 320-15IKB. (DG42A DG52A NMB244 Rev:1.0 PN:5B20N96152 The board has an Intel Core i5 7th gen CPU.)
I connect the power supply, have 20V at some ceramic capacitors near the coils on the picture, but 0V on any coil. When measuring the resistance between the coils and ground, PL401 measures 0R. All the other coils measure at least 10R.
PU401 is a Silergy SY8286BRAC as far as I see.
What shall I do next? Shall I measure the exact resistance between some parts, e.g. capacitors or chips to ground? I have a 6 1/2 digit DMM, but... -
Hello,
I did some more tests. I tried a different BIOS, that changed the charging LED, but only temporarily, so this seems not to be the issue. Everything that follows is measured with the "good" DMM on the coils with the respective number in the picture above.
And I did even risk measuring my good board with voltage again.
4 to 6 measure 0.8V on the good board, but 0 on the bad.
I guess 4 to 6 will be the main CPU power supplies.
4 to 6 measure 3.5R on the bad board to ground and 5R on the good board.
There is 1V at 7 on the good...Leave a comment:
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Hello hoaca388,
thank you a lot for creating an image, but somehow it does not work. Now I guess it's not the BIOS that is the issue. After flashing the BIOS, the charging LED stayed lit some longer than before and now, and there was some blinking and changing to orange on the charging LED, but after about a minute it went out, and about two minutes later I cut the power, and now it looks like before. I do not have a eDP display connected, but a display via USB-C and this did not lit up at all. I guess it was not the BIOS that was faulty. But it was a try. Or do you think, there is more...Leave a comment:
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Hello,
I have a defective 840 G7 and I suspect the BIOS being the issue. UEFITool shows yellow and red lines. I guess this means there is an error.
I attach the BIOS image. I do not know whether there is a BIOS password, but I would like not having to flash the 16MB chip if it is not necessary.
Would someone mind fixing the attached BIOS file or even better explaining me how to fix it myself?
I thank everyone in advance!
SN# 5CG040300Z
ProdID 8PZ98AV
Mainboard: CT:PJSCQ00WBE95J7...Leave a comment:
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For me, the CPU does not seem shorted, but seems to get no power. Do you also think that way?
Can it be a defective BIOS? Do you know how the mainboard acts like when the BIOS is defective?
Upon fixing a password-locked and then defective BIOS on an other model, I know that when the BIOS is defective, mostly it gets read over and over again, but I do not see that here. All the EEPROMs get read and get silent once the charging LED goes off. Very similar to my working 840 G7.
Do I need to reprogram both the 32MB and the 16MB chip when I want to try a different...Leave a comment:
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I did not intend to short that, this was inadvertently by mistake. Somehow my measurement leads make so bad contact with the coils that I hardly measure anything. I see you measure the same voltage on both sides of the coil, but beforhand I measured rubbish and had to measure both sides.
I now measure 21R on both sides of 7. This means here nothing has changed, as my DMM is not so precise, but nevertheless it may have killed the CPU. I shall repair that DMM with contact cleaner spray some day.
I again risked measuring with voltage and used a different DMM and get 0V for 4 to...Leave a comment:
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1: 65R, 0V
2: 8R, 0V
3: 33k, 1.8V
4: 6R, 0V
5: 5R, fluctuating up to 3.3V
6: 5R, fluctuating up to 2.8V
7: 19R, fluctuating up to 4V
8: 172R, 1V
9: 177R, 1.4V
10: 69k, 5V
11: 102k, 4.3V
12: 10k, 3.4V
13: 66k, 5.1V
Upon measuring 7, I short circuit the coil with some 13V capacitor. There was a small spark.
Shorting the measurement leads measures 3R.
[ATTACH=JSON]{"data-align":"none","data-size":"full","data-attachmentid":3578484}[/ATTACH]...Leave a comment:
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I have no USB C meter, but I just powered through a 230V wattmeter. For one moment I measure 1.1W and it drops to 0.7W constant consumption. This power supply measures 0 idle power without the mainboard. And there are 20V on the mainboard somewhere.
I do not have schematics and do not know whether they are available.
I'll search for schematics after I get some sleep. It is late in the night here.Leave a comment:
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HP EliteBook 840 G7 not powering on
Hello,
I have a HP EliteBook 840 G7 that does not power on.
I connect a power supply, for these tests a monitor via USB-C that powers the mainboard. I had RAM, speaker connected, but this does not really make a difference. Most of the time just the mainboard with heatsink and the USB-C power.
The charging light lights up in white for about a second and turns off afterwards. I can see that the 32MB and the 16MB BIOS chip are both read with my scope. There is very little activity on the 1MB chip. After the charging light goes out there is no activity on the... -
Well, to say it killed the laptop is definitivly not the right wording. Sorry. I should have said it just did not work.
I tried the patch on some random 840 G6 BIOS I found here that had produced EC errors and later on on the BIOS from danito to unlock MPM again. Both were unsuccessful. The laptop didn't come alive.
Now the BIOS from hoaca388 works perfectly, but also only on the second try. On the first try I had also yellow-orange blinking pattern on the charge LED. Afterwards I read out the non-working BIOS and somehow the chip got modified a lot. Maybe the BIOS tries to write back...Leave a comment:
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Hey, this is great! Even though I had to flash the 32MB chip twice, probably because my soldering skills are not good enough, now it works perfectly! I did not need BCU nor MPM, it just boots with the correct information, even though it told me once that it has to recover the data because of a mismatch.
hoaca388, you are the best, thanks a lot, and also thank you again danito for trying to help!
Would you mind me asking how you produced these files? Have you handcrafted them in a hex editor, or do you have a tool for that?...Leave a comment:
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Hello,
in the meantime I tried to clear VSS2, but the laptop did not boot any more then.
So I reflashed "New folder (2).rar" in 32MB and 16MB chip and now I am again in MPM, but the LAN Port does not work. I get an error in device manager for the Ethernet controller and cannot set the right MAC address in the BCU or in the BIOS.
Does someone have a clue how to make the ethernet LAN port work?
Thank you in advance!Leave a comment:
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Hello,
you ask for positive feedback. I hope negative feedback is also welcome. I have an EliteBook 840 G6 and this patch kills the laptop. With two different bios images the laptop is dead with the charging LED blinking a specific white-orange pattern after applying this patch. I can confirm that the offsets are correct for my image according to UEFITool. There was no battery neither the main Li-Po nor the lithium Bios coin cell or any other component connected while testing this. Just mainboard, heatsink and RAM. I do not know if this makes a difference.
Nevertheless thank you for...Leave a comment:
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Hey, this is great! A clean BIOS where I can enter the information with the Bios Config Utility!
I now flashed the BIOS, and it boots. Then I entered the information in the Bios Config Utility, but somehow the MAC Address cannot be set. It always stayed at 00-04-80-00-40-00 in the BIOS. Probably because of a defective ME configuration this configuration was not possible. Dumb me, I locked the Manufacturer Programming Mode even though the MAC address does not match. When locking the MPM I entered the MAC Adress in the BIOS so the locking was possible. But on the Information page there...Leave a comment:
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Hello,
I have an EliteBook 840 G6. It had a bios password. Then I tried to read the 32MB BIOS chip, but thereby destroyed the content of this chip.
In the meantime I have unsoldered 32MB and 16MB chip and tried to flash contents available here in the forum, but I did not succeed. The best that had happened was that I had a working laptop, but as soon as I restored the BIOS to factory default configuration the laptop died and never turned on again.
I upload the defective 32MB BIOS and the 16MB chip content with password here.
Would someone mind helping here?
Thank...Leave a comment:
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Hello,
I am Bert from Linz in Upper Austria and I like to fix stuff. Currently I try to remove the password from a few laptop mainboards.
Thank you for all your great support!Leave a comment:
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