Fronczek
Member
Last Activity: 08-03-2024, 02:10 PM
Joined: 01-09-2024
Location: Wąbrzeźno
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Weirdly just like apple laptops... -
If the USB flash doesn't work I'm afraid your only option is desoldering the chip(s) from the board and manually writing the BIOS to them.Leave a comment:
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Hi!
Instead of burning the image, try to download the executable. It has an extract option, and in the extracted folder you get instructions how to make a flashing USB drive.
This might sound controversial, but generally I'd advise against BIOS updates if everything works just fine....Leave a comment:
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Yep, no video at all. The fans are working at the max rpm (I think) and the components are getting hot, and yes the caps led toggles.Leave a comment:
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Got the laptop for repairs without one, and I don't have a 30 pin lcd at the moment. I could order one right now.Leave a comment:
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The laptop is indeed booting, although it seems to be stuck in boot/bios, it doesn't output to HDMI (the matrix is missing at the moment). The charger plugged LED seems to be missing as well...Leave a comment:
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Weirdest thing just happened - plugged in the laptop and saw sparks from a capacitor (PC216). It blew up, so I replaced it for a smaller one but with a higher voltage rating and ACDRV is back??
[ATTACH=JSON]{"data-align":"none","data-size":"full","title":"image.png","data-attachmentid":3243867}[/ATTACH]Weirdest thing just happened - plugged in the laptop and saw sparks from a capacitor (PC216). It blew up, so I replaced it for a smaller one but with a higher voltage rating and ACDRV is back??
[ATT...Leave a comment:
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Sorry my post is in sort of an "Unapproved" limboLeave a comment:
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Weirdest thing just happened - plugged in the laptop and seen sparks from a capacitor (PC216). It blew up, so I replaced it for a smaller one but with a higher voltage rating and ACDRV is back???????????????
#1 (ACN) - 19.95V
#2 (ACP) - 19.95V
#4 (ACDRV) - 26.45V
#5 (ACOK) - 3.3V
#6 (ACDET) - 2.8V
#11 (SDA) - 3.3V
#12 (SCL) - 3.3V
#15 (BATPRES#) - 3.3V
#16 (TB_STAT#) - 1.35V
#17 (BATSRC) - 220mV
#18 (BATDRV) - 250mV
#19-20 (SRN, SRP) - 220mV
#21 (ILIM) - 1.35V
#24 (REGN) - 6V
#25 (BTST) - 5.7V
#26,...Leave a comment:
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ACDRV is gone even without the resistor in question, also why 25V?...Leave a comment:
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Yep, REGN is at 6V and the VCC's being fed 20.3V...Leave a comment:
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Lenovo Legion Y520-15IKBM - No power besides the main rail
Hello people,
I've got this laptop not working for repairs, and as you can see something was done to it as you can see in the coils PL58XX (which I for some reason cannot find in the schematics...) The first FET (PQ201) was not an original part and a questionable one at that and the second one (PQ202) was shorted. Both are N-channel. Ordered replacements for them and replaced them after arrival. Now I have encountered another problem: there is no power at the second FET. By following the thread linked I got to the injection part. Applied 0.8V at 1.5A, but couldn't feel anything getting hot,... -
Alright, I replaced the regulator and my ALW lines are back.
Piernov, I'm not trying to just get an answer to my issue and be gone, I want to actually learn how to check circuits.
The issue is that it's not giving image nor backlight. It's not detected by bios nor OS, and we already established that it's an issue with the motherboard not the LCD screen.Leave a comment:
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All of it will be in the datasheet right? The regulator arrives on Tuesday so see you then!Leave a comment:
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Alright, got it! I have all of these tools available. I purchased the buck controller from a shop closer to my location, apparently they get their supply from Mouser. Should I also purchase the exact mosfet or will one from a donor board suffice?Leave a comment:
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This is much more interesting than I anticipated when starting to learn electronics!
2.73V at ACDET pin. (thank god my vision isn't bad
)
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Measurements are the same. ACOK at PQ10 shows 0V, double checked at PQ9 and it is in fact 0V. Does that mean that the MOSFET is defective or adapter?...
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Good morning!
PU4:
Beeping on pins #3, #10, #13-15 and #18
Visual damage on pin #12 but meter reads 404/405
Pin #11 shows infinite
Power from the adapter is still present:
Mosfet PQ6:
19.9V on source
19.9V on drain
8.4V on gate
Mosfet PQ8:
19.4V on source
19.9V on drain
19V on gate...Last edited by Fronczek; 01-14-2024, 09:14 AM.Leave a comment:
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A little update, when poking around I accidentaly shorted 2 pins on a component marked as PU4 and I think I fried it, since my ALW lines on it don't show voltage anymore.
I always have to make it harder on myself...
Oh well all part of the learning process, now I know that these things require precise instruments and a [U][B]steady hand[/B][/U][I][B]
[/B][/I]At least I'll learn how to solder components onto the board.
Anyway, I identified the component as TPS51225CRUKR_QFN20-HF, and according to the Texas Instruments website it's a "[I]5.5-V...Leave a comment:
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Very good advice and useful knowledge.
PQ6 - 430k
PQ8 - 87k (something I noticed is that on my manual range multimeter when set to max 200k it slowly goes up and stops at around 87k unlike PQ6 which sets it's value almost instantly)
Be safe out there!Last edited by Fronczek; 01-13-2024, 01:42 PM.Leave a comment:
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