Re: A1502 screen only issues

1. It have purchased multiple A1502s from Ebay, so I don't really know the histories of them. But when I opened the latest two, they seemed incredibly clean and didn't appear to have been worked on previously. I have tried the black/blank screen with other 4924 & 3476 boards and it has the same behavior, does nothing. Since I had the cluch cover off on them I took a look at the part numbers and compared them to other known good screens, here is what I found:

Part#, Screen Description
LSN133DL03-A03, cracked screen that works with...

I have a MBP A1502 (early 2015, 820-4924) with a screen that will not turn on. I have swapped screens with a cracked test screen and the computer boots and the cracked screen works for both backlight and image. The black/blank screen appears to do nothing.

I have collected resistant data from the cracked screen connector pins and submitted to OBData server:

1 PPVOUT_SO_LCDBKLT OL
3 I2C_BKLT_SCL 9.97M
4 I2C_BKLT_SDA 9.89M
5 PP3V3_S0_EDP_R 79.10k
6 SMBUS_SMC_0_S0_SCL 321k
7 SMBUS_SMC_0_S0_SDA 323k
8 EDP_BKLT_PWM ...

Re: A1502 820-4924 vs 820-3476 LCD Pinout

Just learned about EDID information stored in the LCD's eeprom. Do you think it would be possible to copy a 2015 MBP LCD EDID and put it on a 2014 MBP LCD. I've recently been getting into eeprom reading/writing. Seems like it would be easy to reprogram a little I2C 24C chip.

Re: A1502 820-4924 vs 820-3476 LCD Pinout

I've been all over the backlight circuits of both schematics and they look identical except a few extra decoupling caps on the PPVOUT_S0_LCDBKLT output. Those decoupling caps wouldn't do much except reduce the noise on the line and provide smoother power.

Also have been looking over the LCD circuits more and at most I see a few more decoupling caps, the U8310 (which looks like a protection circuit that does nothing more than what EDP_PANEL_PWR_OR_PSR_EN did going directly to the panel), and some FLs (FL8300-03) on the data lines....

Re: A1502 820-4924 vs 820-3476 LCD Pinout

Thanks Piernov. I was trying to analyze it from an electrical perspective to understand the differences. I agree they are expensive (worth their weight in gold).

After searching around and not finding a satisfactory answer, I've decided to ask here. I have a 2013/2014 A1502 entire laptop with a 820-3476 board and a separate 820-4924 board only. I want to put the 4924 into the existing chassis.

After comparing the boards I obviously see that the trackpad, trackpad cable, and cable clamp/cover are different which isn't too big of a deal as the parts are fairly cheap.

However, LCDs are in short supply and expensive so I was checking out the LCD/LVSC pinouts and see that pin 5 and pin 10 are swapped (LCD_IRQ_L and EDP_PANEL_PWR_OR_PSR_EN/PP3V3_S0_EDP_R)....

Re: Macbook Air A1466 820-00165-A LIO Board

Louis Rossmann did some videos about onewire circuit from older MB boards that don't have a separate DCin board that he says is similar.

Re: Macbook Air A1466 2015 logicboard 820-00165 turns on BUT no screen and chieme (so

Mario,

Can you post voltages of the different rails like they do in this thread ([url]https://www.badcaps.net/forum/showthread.php?t=78188&highlight=U5110[/url])? That will help to narrow it down.

Thanks,

JoeRe: Macbook Air A1466 2015 logicboar...=U5110[/url])?

Re: New Members - please post your introductions here

Howdy! Aazjo here. I'll been immersed in computers and electronics since I could hold a soldering iron. Lately I've been gaining interest in micro-soldering and component level repair. I remember the bad capacitor fiasco of the early 2000s and find it interesting that the name of this forum is such. Hoping to learn much from you and hopefully be able to share some small tidbit of my knowledge and experience and contribute to the community.