openminded
Senior Member
Last Activity: 12-22-2023, 09:13 AM
Joined: 04-01-2017
Location: home
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hi, did anyone have the boardview for this? I have an issue with no power from usb-c and fans not going on. As such it starts from battery, gets warm and goes off after like a minute. -
Re: MacBook Pro 15" 2017 A1707 Touchbar No power
hi,
Reflowed UB300.
UB300 is now reading 130 mA about.
UB400 has good readings on LDOs and no shorts but does not power on.
Perhaps it's poorly connected on the power lines or broken.
I tried to reflow it, no change.
the ports on the other side work too somehow, 130 mA about.
I suppose UB400 needs to come off again, but given that I have no reballed spare or reball solder, I have to leave it for now.
Unfortunately I...Leave a comment:
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Re: MacBook Pro 15" 2017 A1707 Touchbar No power
hi, thanks for the quick response.
The readings for LDOs are:
u3100 :
pp1v8_upc_xa_ldod : 0.466
pp3v3_upc_xa_ldo : 0.480
pp1v1_upc_xa_ldo_bmc : 0.486
pp1v8_upc_xa_ldoa : 0.503
u3200
pp1v8_upc_xb_ldod : 0.458
pp3v3_upc_xb_ldo : 0.479
pp1v1_upc_xb_ldo_bmc : 0.477
pp1v8_upc_xb_ldoa : 0.496
ub300:
pp1v8_upc_ta_ldod : 0.450
pp3v3_upc_ta_ldo : 0.478
pp1v1_upc_ta_ldo_bmc : 0.474
pp1v8_upc_ta_ldoa : 0.490
...Leave a comment:
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Re: MacBook Pro 15" 2017 A1707 Touchbar No power
man, what a journey
! Could not get ub400 4th point to work. It came off eventually, but I had no reballing tools. Felt lucky, cleaned and fluxed and got it back on with all LDO readings between 0.45 and 0.49 now!
2 caps came off, took an hour to get back, but made it!
All excited, but this is the situation now:
Upper ubc-c port only went on in one plug direction - then it shows 5.19 volt, but now 0.565 amps ( was much lower before, like 0.015-0.150).
Felt that UB300 became warm, so it seems sometimes...Leave a comment:
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Re: MacBook Pro 15" 2017 A1707 Touchbar No power
I was a bit confused, but I think you mean CB306 because it is the LDOA rail?
CB305 resistance was very high.
I moved CB300 - it was replaced before - after that CB306 reading is better : 0.484 with diode mode on ldoa rail.
New diode readings:
ub300:
pp1v8_upc_ta_ldod : 0.443
pp3v3_upc_ta_ldo : 0.466
pp1v1_upc_ta_ldo_bmc : 0.471
pp1v8_upc_ta_ldoa : 0.487
ub400 after same treatment:
pp1v8_upc_tb_ldod : 0 - the cap cb405...Leave a comment:
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Re: MacBook Pro 15" 2017 A1707 Touchbar No power
Hi, thank you for the quick reply!
I measure about 0.9 Ohm in the beginning and then it slowly drops to 0 in about 20 seconds.
Measuring the ground pin of that cap shows 0 first and then goes up a bit.
bad cap? Measuring in bleep mode gives bleep, so looks like a short on it....
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Re: MacBook Pro 15" 2017 A1707 Touchbar No power
Thanks for the help and the peptalk!
I have to say I love the learning anyway and to interact with the community like this, so I will try to keep it going.
The readings for LDOs are:
u3100 :
pp1v8_upc_xa_ldod : 0.466
pp3v3_upc_xa_ldo : 0.482
pp1v1_upc_xa_ldo_bmc : 0.498
pp1v8_upc_xa_ldoa : 0.503
u3200
pp1v8_upc_xb_ldod : 0.460
pp3v3_upc_xb_ldo : 0.483
pp1v1_upc_xb_ldo_bmc : 0.477
pp1v8_upc_xb_ldoa : 0.496...Leave a comment:
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Re: MacBook Pro 15" 2017 A1707 Touchbar No power
Hi,
Thank you, what should the readings be? can´t find it in openboardview.
I replaced it with a new one ( replaced it before but it looked bad )and now it reads 0.53 at both cc points.
Also, it boots with the plug both sides in now - but again to 5.2 V and no rebooting.
More interestingly, UB300 and UB400 side do not go on on any plug orientation now. They used to work both, where one only on one side of USB-c orientation.
The USB power meter I use inline does not go...Leave a comment:
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Re: MacBook Pro 15" 2017 A1707 Touchbar No power
hi, sorry I somehow missed this @mon2 .
here they are :
u3100:
cc1 : 0.59
cc2 : 0.59
u3200
cc1: 0.58
cc2: 0.74
ub300:
cc1: 0.56
cc2: 0.57
ub400:
cc1: 0.56
cc2: 0.57
@powerblackout I have 3.3V on UB2890.
Have an oscilloscope to borrow but never used so would need more instructions.
About missing R41*, those are fine, the do not match the schematics as i saw in the...Leave a comment:
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Re: MacBook Pro 15" 2017 A1707 Touchbar No power
I found : [url]https://www.aliexpress.com/item/1005003614452960.html[/url]
My U2890 shows :
*-8029B ( star is unclear, B might be 8 or 9)
300 (or 800 )
MX25
U3235F
If only the last two lines are important I can order that one and try to program.Re: MacBook Pro 15" 2017 A1707 Touch...ght be 8 or 9)Leave a comment:
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Re: MacBook Pro 15" 2017 A1707 Touchbar No power
Hi, yes I do, just not sure if I have the proper connector, but can order that.
Do you mean programming the current chip or a new one?
Do you have a good link for a replacement chip on ebay?
BIOS image is appreciated, found them on Rossman forums but behind paywal.
My board is 820-00281-A.
Thank you!...Last edited by openminded; 01-26-2022, 05:14 AM.Leave a comment:
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Re: MacBook Pro 15" 2017 A1707 Touchbar No power
I watched [url]https://www.youtube.com/watch?v=alhLFikA3g8[/url] after watching the wiki again. Then I understood the ROM is the TB ROM, U2895 not the EFI ROM (SPI?).
That actually looks like it could be my problem.
I do not have a donor board so I will check chip price and post if news. Glad to still be going and learning, even with no reward of a working board, it is rewarding to learn from all of you guys sharing knowledge.
Thanks a lot!Re: MacBook Pro 15" 2017 A1707 Touchbar No power
Leave a comment:
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Re: MacBook Pro 15" 2017 A1707 Touchbar No power
hi, thanks that is a great find! I have no voltage on both pins.
Also no short. I found the chip here:
[url]https://www.ebay.com/itm/312661170913[/url]
but I am not sure if I want to invest that.
The chip looks good and no power so perhaps problem is power?
Also interestingly I saw no R4106 is on my board, but it does not look like fallen off.
Chip looks clean too but I have cleaned it before so may indeed be dead.
Then I saw R4104 is missing which should power the SPI rom U3906!...Last edited by openminded; 01-25-2022, 02:04 PM.Leave a comment:
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Re: MacBook Pro 15" 2017 A1707 Touchbar No power
adding:
u3100 - no PP1V1 ( but 1.8 and 3.3 LDO ok ) no short on the rail, but 1.8 on PP3V3_G3H - no short measured on either 1.1 or G3H
U3200 - no 3.3 ( PP3V3_G3H - no short ) but has PP1V1 and 1.8
UB400 now 2.6 on 3.3V LDO and most others nothing. no shorts on any caps.
So now I have PP3V3_G3H issues but no apparent short...Leave a comment:
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Re: MacBook Pro 15" 2017 A1707 Touchbar No power
if only it would deliver power.
I read : [url]https://repair.wiki/w/Charger_stuck_at_5_V_instead_of_20_V[/url] a few times and also noticed that my UB400 does not have 1.1V on the LDO.
There is no short either.
I am sick and tired of changing CD3215s by now, did it like 6 times.
This is a hobby and it can cost, but it is no fun.
I found something else that hopefully rings a bell for someone: 2 of my 4 ports work ( usb voltage meter 5.2 V ) when the USB-c cable of the charger...Leave a comment:
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Re: Lenovo IdeaPad Y700 15ISK black screen after boot
hi, I got the replacement screen and cable. Both seem to be fine, but a strange observation. Taking the fully working laptops screen and put it on the broken one, this time gave just a flickering screen and light stripes - mostly looked like just backlight on.
I verified the cable was put on properly, cleaned it, three times the same effect. When I put the screen from the broken one on the good laptop, it works perfectly fine!
Then when I put back the screen from the broken one to it's housing I get the original behaviour...Leave a comment:
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Re: Lenovo IdeaPad Y700 15ISK black screen after boot
Hi thank you for the response. I have another laptop coming so I can compare parts. It's hard to measure those points but I will find a way.
Do you think it is the cable and some kind of resistance causing it to go off?
I really hope it is the issue, that's fixable....
Leave a comment:
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Re: Lenovo IdeaPad Y700 15ISK black screen after boot
a bit more info from testing:
- external HDMI seems to work ok now, just the internal screen is the issue
- when waking up from sleep, the internal screen 'just works' for a few seconds before it goes off again - it still looks like full off, not just backlight
- I ran a stress test with Furu 3D test on a monitor on HDMI and it worked great. so Nvidia GPU seems to work fine.
- with BIOS set to Internal GPU, the Nvidia GPU does not show up in Device Manager but behaviour os screen etc is the same....Leave a comment:
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Re: Lenovo IdeaPad Y700 15ISK black screen after boot
I found out a bit more. It looked like the screen is just on for a few secs, even when waiting on the boot menu screen, it will go off in some seconds.
Also found out that when the LCD cable is disconnected, the HDMI port works and the laptop works fine with an external screen.
I found a BIOS option to set video card to internal only, but the problem remains.
It seems to work all ok when LCD cable is not connected.
I hope this helps anyone help me further, thank you.Leave a comment:
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Lenovo IdeaPad Y700 15ISK black screen after boot
Hi,
I have a strange issue with a Lenovo IdeaPad Y700-15ISK.
It goes on, shows the logo and as soon as it goes further, the screen goes black.
When I use the Novo button, the screen works fine.
When I then choose for example BIOS, I see the BIOS screen for like 1 second, then the screen goes off. The laptop is still on, it responds to the power button, so it seems it works fine except for the screen.
I connected a screen to the HDMI but get nothing, no signal.
It looked like the GPU ( Nvidia 960M ) so I tried to reflow that up until...
No activity results to display
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