hi,
thnks for your effort! I'm looking at least of a boardview / scheme of this mainboard. If you looks 100k jpg there is an other resistor and its 100k. Anyway I think should I find Vin if laptop is off? Because I can find 12V n the 2 capacitors on the right side of resistors and also on other two other capcitors junst under pin 1 of ic. This happen if I attach power keeping disconneted battery. If I plug battery voltage rise to 14V.
shybear
Senior Member
Last Activity: 10-01-2024, 04:11 AM
Joined: 01-05-2010
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As attached picture I think that this IC is TPS51396A 4.5-V to 24-V, 8-A Synchronous Step-Down Voltage Regulator with ULQ.
Reistor is connected to pin12 this is "Enable pin of buck converter."
EN pin is a digital input pin, decides turn on or off buck converter. Internal pull down current to disable converter if leave this pin open.
I'll try to find a schematic with IC then.
...Leave a comment:
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Lenovo ThinkBook Gen 2
hi,
This laptop doesn't power / charge battery next a bit of water entered from rear causing a relly little oxidation (around 10 x 15 mm) near PU5401.
Mainboard p/n is 5B21F20745.
There isn't any sign of overheating and discrete components near the oxidation (capacitors and resistances) are fine.
I've carefully cleanded and removed oxide but as attached picture of oxide damaged area looks like a missed resistance.
I was looking for a boardview or schematic of mainboard without any success, but when power supply is plugged in I can reach... -
Machine doesn't power ON so I wish to try a BIOS reflash. Here's the backup of the original one.
Acer Aspire A315-53G mb: LA-E892P Rev 2A
s/n NXH1AET0048230FEBD3400 SNID 82306521334
Thanks in advance...Leave a comment:
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Thanks. My uploaded original BIOS was wrong due to programmer autosearch feature.
Just for refernece I used the EZP 2010 so must be entered manualy the chip:
For QH128AHIG => GD25Q128 16MB flash
For QH64AHIG => GD25Q64 8MB flash
Anyway also reprogrammed both BIOS but machine still doesn't power on, just amber LED when power on button is pressed.Leave a comment:
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I agree with you peste and I don't know why my post finished in this thread but I'm sure I made a mistake. Anyway this morning I made a new post with right title and posted on BIOS request but it seems it was erased. I think that the best way would be erase my post in this thread and post a new one in BIOS request only, but I don't see a way to do it....Leave a comment:
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Forgive me peste I'm not sure to understand right but do you meanthat should I try the
Vostro-5502.rar from [B][URL="https://www.badcaps.net/member/391642-hoaca388"]hoaca388[/URL][/B] (post #12) ?Forgive me peste I'm not sure to understand right but do you meanthat should I try the
Vostro-5502.rar from [B][URL="https://www.badcaps.net/member/391642-hoaca388"]hoaca388[/URL][/B] (post #12) ?Forgive me peste I'm not sure to understand right but do you meanthat should I try the
Vostro-5502.rar from [B][URL="https://www.badcaps.net/member/391642-hoaca388"]hoaca388[/URL][/B]Leave a comment:
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hi,
I've here this laptop. It doesn't power on and the only activity is the LED near power jack that ligh on amber just when power button is pressed.
There isnt' any visible problem or damaged component so far.
So Id' like to try a BIOS reflash then I need a dump BIOS.
Machine is: Dell Vostro 5502 (Model P102F002) Intel i5 CPU Service Tag 1M3YR93. MB model number #19862-1 CN-0N9CJ5
I attach also the original BIOS.
[ATTACH]n3289880[/ATTACH]...Leave a comment:
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Re: ASUS X409DL REV 2.0 boardview need
Really many thanks from me too, someone destroy battery connector so better to have boardview to reconnect it correctly!Leave a comment:
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Re: LG 47LB67 power board EAX65424001 issue
Solved: there is also to move R724 (47K) to R725 (se attachment), and now backlight works fine....Last edited by shybear; 03-29-2023, 01:58 PM.Leave a comment:
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LG 47LB67 power board EAX65424001 issue
hi,
This TV sometimes shut off itself surely for some bad contact of power supply board that (for use and heat) wasn't planar anymore.
Found a same on ebay at an affordable price and compared part number and component side components was exactly the same I bought it.
The board is perfect and new and the random shut off problem disappeared but there is a dark side on the screen that isnt' present with the old board.
Take a look on the back of the newe power board I noticed that this one hasn't some components (4 resistors and 3 transistor) that made me... -
Re: Canon Pixma MG2550S dump BIOS
no, this one is just the copy of orginal BIOS when the printer was still locked with error.
Try the one of #20 of shutt1e but take care about s/n!
I suggest you before to goes on to make a backup copy of your original BIOS.
I also suggest to try to fix the issue using service tool 4718 that is compatible with mg2550s!!! (see#16)...Leave a comment:
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Re: Canon Pixma MG2550S dump BIOS
If you quickly seach for 4g08 you'll find its an eeprom!
If you doesn't have the right adapter socket you should have an adapter (that usually is inside programmer kit) where chip have to be soldered (see picture)....Leave a comment:
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Re: Canon Pixma MG2550S dump BIOS
...see the attached picture, this one is the memory if I still remember well!...Leave a comment:
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Re: HP 250 G5 death
First of all thanks! I know you wanted to know if I was right to say that mosfet are ok, so I was not so specific just to explain how I test these components.
Anyway for future reference help:
pin 1-2-3 => SOURCE
pin 4 => GATE
pin 5-6-7-8 DRAIN
so if the component is good GATE must be isolated for drain an source, so:
pin1-pin4 =>infinite
pin8-pin4 =>infinite
Between source and drain there is a junction so I usually test it putting tester under DIODE mode then:
pin1-pin8...Leave a comment:
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Re: HP 250 G5 death
Man you're a genius!!!
I didnt't know this type of adaptor is smart power and you're 100% right.
I just tried with an original power adapter for and HP Spectre and even if this one is just a 45Watt, if I connect it to power jack the led light on!
Really thanks so much for help!!!...Leave a comment:
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Re: HP 250 G5 death
PQ201 its not mounted on this mobo!...Leave a comment:
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Re: HP 250 G5 death
Following your direction I removed PR208 (4,12K) but ACDRV is still 0V.
If I inject directly 19V on the OUT(pin1-pin3) of PQ202 I measure 25,6V on gate (pin4)....Last edited by shybear; 02-03-2023, 05:32 AM.Leave a comment:
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Re: HP 250 G5 death
Thanks, yep if I'm right gate must be isolated from drain and source and also I tested between IN(pin5-pin8)- OUT(pin1-pin3) in diode mode.
I bought anyway PQ202 (same as the mounted one) even if the original one tested with tester was fine....Leave a comment:
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Re: HP 250 G5 death
I also checked PQ203 (right now without desolder it) and it seems to be fine.
I just checked again all small capacitors around PQ202 and no shorts....Leave a comment:
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