Re: iMac 21,5 Late 2013 A1418 (EMC 2638) Display dead no 4th Diagnostic LED
I bought a new display and works fine until now (3 years)
Funkwarrior
Member
Last Activity: 04-13-2024, 03:33 AM
Joined: 02-28-2016
Location: Pordenone
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Re: Openflex Boardview: New boardview software (linux, windows and OSX)
Thank you!...Leave a comment:
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Re: Marantz NR-1504 No power
Hello,newbie here.
I have a NR1604 with the same issue, no 5,2 VDC to HDMI board.
I've replaced TOP258, diodes D4142, D4143, D4144, D4145 as suggested in the service manual, caps C4152, C4155, 1M resistors R4141, R4142, R4164 (with bigger wattage).
I have on TOP258:
S - V(1) 5,6 VAC
S - X(2) 2,4 VAC
S - C(3) 11,1 VAC
S - D(4) 711 VAC
I'm afraid to have messed up diodes orientation, even if I checked dozens times.
Can somebody can give a hint?
Thanks!Leave a comment:
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Re: Lenovo G50-70 ACLU1/ACLu2 NM-A271 Rev. 1.0 no power
I got 3,65V on +3VLP, tested on PJ304 Jumper. No EC_ON and no +3VALW.
So now I hope it's only the EC to change: it's the safest and quicker way to solve, right?
I don't think I will buy a programmer just for this chip...
Thanks piernov!Leave a comment:
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Re: Lenovo G50-70 ACLU1/ACLu2 NM-A271 Rev. 1.0 no power
Hello, I resume this thread, hopefully to resolve this problem.
I resoldered with better tools the PU301 and now I have this values using an original Thinkpad 45w power supply :
[b]PU301[/b]
[b] 1 ACN [/b] 20,70
[b] 2 ACP [/b] 20,7
[b] 3 CMPOUT [/b] 0
[b] 4 CMPIN [/b] 0
[b] 5 ACOK [/b] 0
[b] 6 ACDET [/b] 2,7
[b] 7 IOUT [/b] 0
[b] 8 SDA [/b] 0
[b] 9 SCL [/b] 0
[b] 10 ILIM [/b] 0
[b] 11 BM# [/b] 0
[b] 12 SRN [/b] 1,9
[b] 13 SRP [/b] 1,9...Leave a comment:
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Re: Mac mini 820-2366-a
nobody have it?
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Mac mini 820-2366-a
Hello, I searching for 820-2366-a schematics and boardview.
Thank you -
Re: iMac 21,5 Late 2013 A1418 (EMC 2638) Display dead no 4th Diagnostic LED
when the screen goes black, there is nothing visible under a flashlightLeave a comment:
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Re: iMac 21,5 Late 2013 A1418 (EMC 2638) Display dead no 4th Diagnostic LED
Nobody can give me some tips?Leave a comment:
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iMac 21,5 Late 2013 A1418 (EMC 2638) Display dead no 4th Diagnostic LED
Hello,
I'm trying to repair an iMac A1418 (EMC 2638) which display fault.
Seems on cold boot display works fine but after a while begins to flickering to a black screen.
I tried an external monitor and it works, correctly.
The board is a 820-3588-A (files attached).
When the display is active and alive, I think all values are ok:
Diagnostic LED: #1 ON #2 ON #3 ON #4 ON
J8100
LED_RETURN_1 4,5V (sometimes 11,5V)
LED_RETURN_2 4,5V (sometimes 11,5V)
LED_RETURN_3 4,5V (sometimes 11,5V)
LED_RETURN_4 4,5V (sometimes... -
Re: Lenovo G50-70 ACLU1/ACLu2 NM-A271 Rev. 1.0 no power
Change of mind, in the next days will try to understand what I've done..Leave a comment:
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Re: Lenovo G50-70 ACLU1/ACLu2 NM-A271 Rev. 1.0 no power
Sorry @piernov, but I think I fried the board... I need more experience with this kind of soldering.
Thank you, I really appreciate your help.Leave a comment:
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Re: Lenovo G50-70 ACLU1/ACLu2 NM-A271 Rev. 1.0 no power
Tested all PQ with Multimeter on circuit:
All with Positive lead on Source and negative lead on Drain in Diode mode gives me Resistance between 0.555 and 0.571 expect PQ309 with high resistance. So I took it off board and tested: Resistance 0.580.
I have also a short between on pin 1 and 2 onboard with PU301 offboard.
Now i will reinstall PQ309 e retest it onboard.
New BQ24737 arrived. I have to worry about the PIN1 and PIN2 short or I can install BQ24737 and test values again?
I hope I don't...Leave a comment:
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Re: Lenovo G50-70 ACLU1/ACLu2 NM-A271 Rev. 1.0 no power
Thanks again @piernov, really.
The datasheet of BQ I reading was wrong, sorry. (Why the BQ24737 datasheet is impossible to find?).
These are the values according to pin output of the board schematics.
I need to desolder PQ301 and PQ302 to test the Drain and Source, right?
Thanks again!
[b]PU301 - BQ24737[/b]
[b] 1 ACN [/b] 20.3
[b] 2 ACP [/b] 20.3
[b] 3 CMPOUT [/b] 0.1
[b] 4 CMPIN [/b] 0.1
[b] 5 ACOK [/b] 0.1
[b] 6 ACDET...Leave a comment:
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Re: Lenovo G50-70 ACLU1/ACLu2 NM-A271 Rev. 1.0 no power
Thank you @piernov!
I desoldered and resoldered again the BQ and cleaned well the board. The PQ301 legs were a bit dirty.
(I want to apologize for my boring questions and my incompetence...
)
Anyways, is the new values:
[B]PU301 - BQ24737[/B]
[b] 1 ACN [/b] 20.3
[b] 2 ACP [/b] 20.3
[b] 3 CMSRC [/b] 0.1
[b] 4 ACDRV [/b] 0.1
[b] 5 ACOK [/b] 0.1
[b] 6 ACDET [/b] 0.4
[b] 7 IOUT [/b] 0
[b] 8 SDA [/b] 0
[b] 9 SCL [/b]...Leave a comment:
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Re: Lenovo G50-70 ACLU1/ACLu2 NM-A271 Rev. 1.0 no power
I tried to refit the first bq24737 i tried to install, as long as I wait for the new one.
The values are correct now? (without battery attached)
[b] 1 ACN [/b] 20.3
[b] 2 ACP [/b] 20.3
[b] 3 CMSRC [/b] 1.3
[b] 4 ACDRV [/b] 0.3
[b] 5 ACOK [/b] 0.1
[b] 6 ACDET [/b] 2.6
[b] 7 IOUT [/b] 2.3
[b] 8 SDA [/b] 1.9
[b] 9 SCL [/b] 1.4
[b] 10 ILIM [/b] 1.5
[b] 11 BATDRV [/b] 0.2
[b] 12 SRN [/b] 19.9
[b] 13 SRP [/b] 0.1
...Leave a comment:
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Re: Lenovo G50-70 ACLU1/ACLu2 NM-A271 Rev. 1.0 no power
really?
I'm so stupid..Leave a comment:
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Re: Lenovo G50-70 ACLU1/ACLu2 NM-A271 Rev. 1.0 no power
Hi all, I'm back! Sorry but I'm a bit sick and sometimes I can't going forward as I please.
Anyway, I replaced the PU301 - bq24737 with a bq24735 ([URL="http://anonym.to/?https://e2e.ti.com/support/power_management/battery_management/f/179/p/635560/2347780#2347780"]link to TI forum support[/URL]) and the resistor blowned and here's my new values :
[b] 1 ACN [/b] 20.3
[b] 2 ACP [/b] 20.3
[b] 3 CMSRC [/b] 0.1
[b] 4 ACDRV [/b] 0.1
[b] 5 ACOK [/b] 0.1
[b] 6 ACDET [/b] 2.6...Leave a comment:
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Re: AEG BSS 4823 - portable speaker - Crackling noise from one channel input
Maybe someone can help me if he recognized the noise from the video?
[URL="https://www.dailymotion.com/video/x6knv0u"]https://www.dailymotion.com/video/x6knv0u[/URL]
Any help is really appreciated, thanks!Re: AEG BSS 4823 - portable speaker - Crackling noise from one channel input
Maybe someone can help me if he recognized the noise from the video?
[URL="https://www.dailymotion.com/video/x6knv0u"]https://www.dailymotion.com/video/x6knv0u[/URL]Leave a comment:
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Re: AEG BSS 4823 - portable speaker - Crackling noise from one channel input
Maybe it's easier if I put directly the images:
Front (preamp?)
Amplifier (on a Backplate)
Video with audio problem:
[URL="https://www.dailymotion.com/video/x6knv0u"]https://www.dailymotion.com/video/x6knv0u[/URL]
I changed two capacitors that appeared with some leakage (visibles in 3rd image)
Also tested the resistors of both channel input of rca inputs and bluetooth/usb inputs and seems...Leave a comment:
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