Re: Smartbook 141 C4 not charging and only works on battery
So as it turns out the bad MOSFET was all that was wrong.
Internet said it takes 5V 4A input but in reality the input has to be 12V.
I found this out through the battery charger IC datasheet, which is here:
[url]https://cdn.badcaps-static.com/pdfs/c4ae34992c0739c1e21d050d530c6758.pdf[/url]
As it turns out ACDET pin needs at least 2.4V to turn on and at 5V it would get only around 1V.
But at 12V it would get 2.5V, basically confirming the fact that it needs 12V on the input.
So i switched...
PopcornMobo
Senior Member
Last Activity: 01-23-2023, 07:28 AM
Joined: 12-02-2017
Location: Lithuania
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Smartbook 141 C4 not charging and only works on battery
Okay so i found this Smartbook 141 C4 in the e-waste and it seemed a little too nice to just throw away.
The problem comes down to it not being able to charge or work at all on the DC input.
I don't know if this laptop is supposed to work on DC with the battery unplugged but it doesn't regardless.
I don't have a charger for it but google says it's 5V 4A and i can do that with an ATX PSU no problem. Alas, 5V on the input does nothing.
So i charged the battery with my bench supply at 2A for a couple hours and it seems to have taken some charge.
Enough to power...Last edited by PopcornMobo; 01-20-2023, 12:12 PM. -
Re: Toshiba Satellite L50-B-281, DGPU fault, works on iGPU only.
Reballing is not my cup of tea.
I might try another reflow in the oven but this time i'll remove the underfill from around the GPU.
Can't really do that now because i'm renovating my lab/workshop, but i should be finishing up on that soon....Leave a comment:
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Toshiba Satellite L50-B-281, DGPU fault, works on iGPU only.
Local PC repair guy had some laptops in the e-waste bin so i bought them for cheap, as i do.
He said all of them work but they all have issues, and it's true.
My focus in this thread is the Satellite L50-B-281, which was in the bundle.
The laptop originally had the hinge support broken off completely in the lower chassis/bottom cover.
I fixed the broken plastic with hot glue and it's all fine now, except for the GPU.
When i pulled the heatsink apart i found a huge load of lint and dust buildup so the laptop was most likely constantly overheating.
As it...Last edited by PopcornMobo; 03-05-2020, 03:37 PM. -
Re: Gigabyte HA65M mobo random shut down, bad bios?
Update: False alarm.
Got my E3 1220 and installed it in the mobo.
At first nothing worked but turns out my 8500GT was dead, popped in a known working 6800GT and got an image.
Installed windows 7 and everything went fine, installed CPUZ, Speedfan, Unigine Valley benchmark and everything went fine.
Benched the CPU in CPUZ and everything went fine, have you noticed a pattern here?
I then shut the PC down and it didn't restart in 3 seconds after it shut down so that confirms it.
The board is...Leave a comment:
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Gigabyte HA65M mobo random shut down, bad bios?
I got this gigabyte mobo, full model GA-HA65M-D2H-B3 and the guy who sold it says that it works and you can install the OS but as soon as you try to install any other program it shuts down.
He also said that there was one issue from day 1 when it was still working he told me that if he tried to eject a device from the USB3 port about 1/5 of the time the PC would fail to eject and would eventually blue screen
The socket pins look good and all the caps are solid caps so i think they're not the cause of the problem, there's also no external damage that i can see.
I don't...Last edited by PopcornMobo; 10-17-2018, 08:35 AM. -
Re: AOC 2216Sa monitor displaying weird colors.
I updated the original post.
It's hard to get a decent picture of a screen without aliasing, but the one i got looks good enough.
The red in the windows logo shows the dark vertical lines well and the blue shows the bad transitions between shades of colors.
It's like the screen is trying to display the image in a compressed/low-bit mode....Last edited by PopcornMobo; 10-07-2018, 04:56 PM.Leave a comment:
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AOC 2216Sa monitor displaying weird colors.
I found this monitor at the dump right when i was in the need of one.
The monitor is not smashed and works fine.
The lack of "LED" stickers on it tells me that it's got CFL in it.
One thing about it is that it's displaying colors wrong.
It's like there's these very rough transitions between various shades of colors, almost as if there's only about 32 colors.
Also every second vertical line of pixels is darker where the image is also dark.
The only example to describe this i can think of would be maybe a compressed image.
Now that i think...Last edited by PopcornMobo; 10-07-2018, 04:49 PM. -
ASUS R7 360 no image but drivers install fine.
I bought this ASUS R7 360 OC 2GD5 quite a while ago but didn't have the opportunity to properly test it, i had it in one PC and it gave no signal but was an old PC and i'd read previously that this card can give no image on older HW.
Until recently i didn't have a mobo with an IGPU but now i have one and decided to give the R7 360 another go.
With the display plugged into my IGP i checked if the card was being detected.
It was detected and it even installed the drivers without any issues, but when i plugged my display cable into the GPU i would get no signal.
Externally...Last edited by PopcornMobo; 10-07-2018, 09:06 AM. -
Re: Weak 5V line, Nexus RX-5300 530W modular PSU.
Fixed, i think....
As mentioned above i was not getting power good so i looked at the function table in the WT751002 datasheet.
PGI (power good in, pin1) had to be above 1.2V to send a PG signal, mine was at 0.06V
The PGI signal is derived from the +5V tap at the transformer and gets rectified through a tiny SMD diode (D19), in my case the diode was showing a 0.2V drop both ways and would only show 3V rectified so i replaced it with a SMD shottky diode i had.
After i replaced the diode the rectified voltage...Leave a comment:
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Re: Weak 5V line, Nexus RX-5300 530W modular PSU.
I did some bodging but did not achieve much. I found a 400W PSU schematic and copied the resistor divider network from it to my PSU but it didn't work well.
5V was ok, 3V3 was ok as well but 12V rail was way too low so i took my bodge out and replaced the original resistor divider.
The PSU works as it did before the mods so no harm there.
Another important thing (i think) is that my power-good (gray wire) signal is low, and wikipedia says it should be high, so i'll have to investigate that.Leave a comment:
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Re: Weak 5V line, Nexus RX-5300 530W modular PSU.
I took two pics, one of the supervisor IC area and one of the 5V and 3v3 areas.
Please excuse the fluxy mess
Edit: calculated what the TL431's trigger at, on the 5V side it's 5.194V and 3.435V on the 3V3 side.
I might just hook those TL431s to the voltage feedback opto i think....Last edited by PopcornMobo; 10-06-2018, 02:46 AM.Leave a comment:
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Re: Weak 5V line, Nexus RX-5300 530W modular PSU.
Turns out the diode was the rectifier for the -12V rail. Another thing is that there's a WT751002 supervisor IC, which should take care of things but it doesn't really help much.
There are three optocouplers in total, one is for voltage feedback, other is for 5VSB feedback and the third is for fault feedback.
All are on when the PSU is running, if fault feedback opto is turned off then the PSU shuts down.
Since the PSU is running there are no detected faults by the supervisor, also the 5VSB is good so i can rule...Leave a comment:
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Re: Weak 5V line, Nexus RX-5300 530W modular PSU.
Some more stuff i found out.
I gave the 12V rail a 2.3Ω load and quickly noticed smoke coming from the power supply.
At first it looked like it was coming from a capacitor but turned out there was a cheeky little shottky (SB2100) hiding under the huge output common mode choke.
When i took it out it was well smoked and completely shorted, i replaced it with some other shottky, not sure what the model was but it was about 4x bigger
Now the PSU seems to be working much better but it's not perfect....Leave a comment:
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Re: Weak 5V line, Nexus RX-5300 530W modular PSU.
Just checked all the caps on the primary side and they're all good.
One thing i noticed is that with a 15Ω resistor the 5V rail dips down to 4.2V but all the other rails stay unaffected, i might have to do some more testing.
The 5VSB rail that is created by a separate supply is always there and is not affected by any of the main power rails.
I'll go hook up a scope on the 5V rail to check the ripple....Leave a comment:
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Re: Delta ATX PSU refuse to start
5VSB is created but a separate standby power supply so it won't indicate whether the PSU is good or not.
Older PSUs tend to have a controller IC on the secondary, this IC controls the switching transistors through a transformer that's driven by two small transistors, you might want to check those.
Also, what did the PSU do when (if) you connected the green and black together, did it make a noise like tick, click, buzz or anything?Leave a comment:
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Re: The Cheapest ATX Power Supply on Amazon Prime, How bad can it be?
Why recap, might as well buy a better PSU....Leave a comment:
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Weak 5V line, Nexus RX-5300 530W modular PSU.
Since i'm kind of broke i had the brilliant idea to go and buy a defective PSU from the local PC parts guy and try to fix it.
I got this pretty nice looking RX-5300 with all the cables for 5€.
As soon as i got it i took it apart in search of bad caps (as you do) but much to my surprise they were all good.
Plugging the PSU into a known good mobo results in a no post, so i took the PSU to the bench and started measuring voltages.
No load 12V and 5V were all good but as soon as i put a 3R9 resistor on 5V it dipped down below 1V and the PSU started squealing and resetting,...Last edited by PopcornMobo; 10-05-2018, 08:31 AM. -
Re: Is my DWA-525 Pcie network card crapping out?
Looks like i went off to modding the card before i posted the reply above.
Well i stuck on a rather large heatsink from an AGP GPU with the help of a thermal pad, double sided tape and a piece of steel bent to a C shape to press the heatsink against the BGA.
And *drumroll* the card works now!
Not sure whether it's the heatsink or the pressure against the BGA but the card works without crapping out now, which is what matters.
Now my little bro can play minecraft on his new pentium 4 520 beast...Last edited by PopcornMobo; 09-23-2018, 02:29 PM.Leave a comment:
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Re: Is my DWA-525 Pcie network card crapping out?
I took the PSU apart and found two bulged caps so i thought bingo.
Replaced them with some nichicons and the card still does what it did.
Although touching behind the card feels quite warm, might that the little BGA is overheating.
I'll try taking the shield off and sticking on a heatsink.Leave a comment:
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