Re: 5-band resistor starting with black?
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JenneDezaeger
Member
Last Activity: 12-12-2022, 10:44 AM
Joined: 02-16-2021
Location: Antwerpen
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Re: 5-band resistor starting with black?
How did you get to that?Leave a comment:
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5-band resistor starting with black?
Can anyone tell me how it's possible for a 5-band resistor to start with black?
If it really was a zero-ohm resistor it probably wouldn't have burned.
So if there are any ideas on the value of this resistor and how to read it, please let me know.
Greetings,
Jenne... -
Re: A1708 intermittent backlight (no flexgate issue)
I reflowed every power IC en it worksLeave a comment:
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Re: A1708 intermittent backlight (no flexgate issue)
OK so I discovered if i spray the CPU heatsink with freeze spray it turns on.
But sometimes with artifacts on the screen.Last edited by JenneDezaeger; 03-17-2021, 04:24 AM.Leave a comment:
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Re: A1708 intermittent backlight (no flexgate issue)
If I measure on the "big" caps like C1163 you said they would be low resistance, but I get 2.4Ohms. Is that normal?Leave a comment:
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Re: A1708 intermittent backlight (no flexgate issue)
The speakers are not connected so i suppose the chime is playing if I get the logo, but that is only after I leave the board for a while, and as I said, if it starts it blacks out after a couple of minutes and then it doesn't do anything. I see the current go up to 580mA and I can shut it down with the powerbutton, but no backlight but also no image.
But when it works, everything works also the backlight.
Any pointers on which caps to start with, because otherwise I would be busy for quite a while.Leave a comment:
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Re: A1708 intermittent backlight (no flexgate issue)
Apparently when I leave the board for 15-20 min without battery and without power and I then plug it in it starts, if I then disconnect the USB-C and reconnect it doesn't start.
When it works it draws around 450mA, when it doesn't it jumps to 580mA. Sometimes when it starts it stops working and also jumps to 580mA.Last edited by JenneDezaeger; 03-16-2021, 11:30 AM.Leave a comment:
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Re: A1708 intermittent backlight (no flexgate issue)
OK, so I replaced the screen and have the same problem.
It starts and draws around 0.580A @ 20V and I can turn it off by holding the power button.
But still no backlight!
If I connect an external monitor nothing show either and I can't seem to see the logo at startup, so it could be no image.Last edited by JenneDezaeger; 03-16-2021, 09:16 AM.Leave a comment:
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Re: MTS70-0512ACW going into protection
No, that's just flux residue you're seeing. I did work on the board allot and didn't clean it between each thing i tried.Leave a comment:
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Re: MTS70-0512ACW going into protection
All the caps have been tested and even replaced without reason and it didn't make a difference. I took some pictures of the board, but keep in mind that the small boards are out of place zo I could reach them to measure while the PSU is running. I took a separate picture of the oscillator board that I'm now running from a bench supply which gives me the result from my initial post.
Maybe one more thing, when I power the TEA1610T without it being on a pcb or without any passives it off course doesn't oscillate because of the missing...Leave a comment:
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MTS70-0512ACW going into protection
Hi,
I've spend the last 3 days trying to figure out what is causing this smps to go into protection.
Because it only powers on for a split second it's almost impossible to measure anything.
That's why I removed the oscillator board (it's a separate board) and powered it externally.
The TEA1610T showed me this at the gate outputs:
So I assumed a faulty driver and was a bit surprised it went into protection instead of blowing up the FET's.
I replaced the IC (even twice) and I still get the same problem.
Does anyone have an idea what... -
Re: A1708 intermittent backlight (no flexgate issue)
I've ordered a new screen just to rule it out.Leave a comment:
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Re: A1708 intermittent backlight (no flexgate issue)
I've measured the lid sensor and it seems fine.Leave a comment:
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Re: A1708 intermittent backlight (no flexgate issue)
Could it be that although the screen flex looks OK, that my BKLT_EN_R is missing because of bad communication between the screen and the board? I haven't got another screen to test with for the moment but maybe I should try that.
An external screen isn't possible without a working internal display as far as I know, so it's hard to tell what is happening, but I've seen it boot into the login screen on 1 occasion.Leave a comment:
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Re: A1708 intermittent backlight (no flexgate issue)
It's indeed a mid 2017Leave a comment:
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A1708 intermittent backlight (no flexgate issue)
Hi,
I have a 1708 with a 820-00840-A board.
Sometimes I have backlight, I say sometimes because i haven't figured out the pattern when it works and when it doesn't. It doesn't seem to respond to temperature changes (hot or cold).
I do notice when it works and I unplug it and try again it doesn't work anymore, if I leave it for a while sometimes it starts again.
The reason that there's no backlight is because my BKLT_EN_R is 0V (except when it works off course, than its 3.3V).
I've tried and measured everything I could think off. Does anyone have an idea... -
Re: New Members - please post your introductions here
Hi,
I'm an embedded systems engineer that started a company in electronics repairs in the B2B scene quite a while ago. Lately I've been repairing more and more consumer devices so being part of Badcaps where a lot of knowledge and information is available is a plus.
Greetings JenneLeave a comment:
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