thanks for your videos. i have a problem with a iphone 6 and no backlight. there are no shorted components and no short on vcc main. with batterie i have 3.8v and with usb only i have 4.3v. coil, diode, caps and ic are ok. with batt and usb plugged in i have a kind of a "jumping" voltage between 3.8 and 4.3v. no voltage boost on backlight circuit, only 3,8v or 4.3v, or "jumping if batt and usb is connected. any idea where the problem could be? thanks
While the vcc_main voltage jumping around is definitely odd I can't see how that's a direct cause of no backlight. I'm guessing the jumping has something to do with charging turning on & off, or the USB power not getting to tigris reliably. As I mentioned you can probe the gate of Q1403. You can also probe VBUS_DET which goes high when Tigris detects power on the VBUS (USB power)
When the phone is charging the battery, vcc_main will be only slightly above the battery voltage, this is NORMAL. In itself that doesn't mean something is wrong. Power flows from the usb through Tigris (with the help of it's charging coil) to vcc_main then to the battery through Q1403. If you check on zxw you'll see that the gate of Q1403 is actually probeable, so you can verify if Tigris has turned it on. It is my personal working model that Tigris charges at a lower current (usually .5 amps) until given permission from the CPU to charge at a higher rate. Thus, to get that higher charging rate you need the CPU and probably Tristar working. This is why we see .5 amps on the USB and we know the phone is not happy...
So, i think the "tell" is to use a battery that is not fully charged and if vcc_main goes up to 4.2V, then you can assume that tristar is working properly. VCC_main will not go to 4.2V if tristar is not working properly, unless the battery is already fully charged.
hi, amazing work!! I dont understand the flow , from wich component to wich one and why, and the second questions is the function of Q1403, and why Tristar if its failing it doesnt show on vcc_main the "USB Voltage" Thanks for all hard work
If you look at the schematics you'll see that Q1403 is being used as a switch that connects batt_vcc and vcc_main. Tigris controls this switch. This is done when a) the phone is being powered from the battery (in which case power flows from batt to main) or b) the phone is charging the battery. (in which case power flows from main to batt) As to "Tristar if its failing it doesnt show on vcc_main the "USB Voltage"", in my opinion it's a bit more complex than that, but unfortunately this isn't exactly the environment to discuss it.
Tigris controls the gate, but what do you think controls the voltage that Tigris sends to that gate? It's the enable line from Tigris to Tristar. Without that handshake, there is no gate voltage at the transistor, thus there is no switching from Q1403. In order for vcc_main to see the usb voltage, tristar has to be working. IMO.
In an i6 (and maybe others) you can also probe that enable line (Tristar_to_PMU_OVP_SW_EN_L) by scraping away above a via. My experience is relatively limited but I've tried several times checking that out when there are charging issues and it's always been low (enabled). My personal model (which may or may not be accurate) is that the CPU once live can control Tigris through the serial port (I2C1), and often the CPU can't go live without Tristar. Same cause, different reasoning.
Excuse me sir, want to ask ic charging it including cause batrai error not yes .. because in the battery 100% in let stand 5 hours runs itself to 0% said technicians at the counter ic charging ... thanks Microsoldering
Trying to remove the chip following your directions but I'm not able to pull it out. Only melt it down... any advise (besides dedicating to somethig else?)
in older videos, I was using the hakko fm-202 w/fm-2023 microtweezers. In the newer videos, I use the JBC NASE-1B. Check the description with links on where to buy.
Great information straight to the point
NO bullshit life story's
I will share this video with all MicroSoldering guys
can i use u2 chip from 6 to 6 plus ?
I generally prefer practicing than watching videos. I have found your videos very useful though
very help full video.thanks for the video.....
thanks for your videos. i have a problem with a iphone 6 and no backlight. there are no shorted components and no short on vcc main. with batterie i have 3.8v and with usb only i have 4.3v. coil, diode, caps and ic are ok. with batt and usb plugged in i have a kind of a "jumping" voltage between 3.8 and 4.3v. no voltage boost on backlight circuit, only 3,8v or 4.3v, or "jumping if batt and usb is connected. any idea where the problem could be? thanks
Man Sch do you see a faint image on the screen?
While the vcc_main voltage jumping around is definitely odd I can't see how that's a direct cause of no backlight. I'm guessing the jumping has something to do with charging turning on & off, or the USB power not getting to tigris reliably. As I mentioned you can probe the gate of Q1403. You can also probe VBUS_DET which goes high when Tigris detects power on the VBUS (USB power)
no, there is nothing on the screen.
where do you get your schematics ?
pei broker try GSM hosting forums
Microsoldering
When the phone is charging the battery, vcc_main will be only slightly above the battery voltage, this is NORMAL. In itself that doesn't mean something is wrong.
Power flows from the usb through Tigris (with the help of it's charging coil) to vcc_main then to the battery through Q1403. If you check on zxw you'll see that the gate of Q1403 is actually probeable, so you can verify if Tigris has turned it on.
It is my personal working model that Tigris charges at a lower current (usually .5 amps) until given permission from the CPU to charge at a higher rate. Thus, to get that higher charging rate you need the CPU and probably Tristar working. This is why we see .5 amps on the USB and we know the phone is not happy...
So, i think the "tell" is to use a battery that is not fully charged and if vcc_main goes up to 4.2V, then you can assume that tristar is working properly. VCC_main will not go to 4.2V if tristar is not working properly, unless the battery is already fully charged.
hi, amazing work!! I dont understand the flow , from wich component to wich one and why, and the second questions is the function of Q1403, and why Tristar if its failing it doesnt show on vcc_main the "USB Voltage" Thanks for all hard work
If you look at the schematics you'll see that Q1403 is being used as a switch that connects batt_vcc and vcc_main. Tigris controls this switch. This is done when
a) the phone is being powered from the battery (in which case power flows from batt to main) or
b) the phone is charging the battery. (in which case power flows from main to batt)
As to "Tristar if its failing it doesnt show on vcc_main the "USB Voltage"", in my opinion it's a bit more complex than that, but unfortunately this isn't exactly the environment to discuss it.
Tigris controls the gate, but what do you think controls the voltage that Tigris sends to that gate? It's the enable line from Tigris to Tristar. Without that handshake, there is no gate voltage at the transistor, thus there is no switching from Q1403. In order for vcc_main to see the usb voltage, tristar has to be working. IMO.
In an i6 (and maybe others) you can also probe that enable line (Tristar_to_PMU_OVP_SW_EN_L) by scraping away above a via. My experience is relatively limited but I've tried several times checking that out when there are charging issues and it's always been low (enabled). My personal model (which may or may not be accurate) is that the CPU once live can control Tigris through the serial port (I2C1), and often the CPU can't go live without Tristar. Same cause, different reasoning.
Excuse me sir, want to ask ic charging it including cause batrai error not yes .. because in the battery 100% in let stand 5 hours runs itself to 0% said technicians at the counter ic charging ... thanks Microsoldering
i'm getting 2.7 volts at vbat which is low. So if there's a problem on vbat , could that be a tigris problem
Mem Baker I suspect bad battery
Trying to remove the chip following your directions but I'm not able to pull it out. Only melt it down... any advise (besides dedicating to somethig else?)
Turn up the heat and turn down the air flow.
Thanks a lot for the answer!
Very well done, Thank you
Hi microsoldering
How did you learn to repair mobile phone
liboy34 mainly trial and error. It probably helps that I am an electrical engineer
thanks
soldering iron with two ends where you bought a friend
in older videos, I was using the hakko fm-202 w/fm-2023 microtweezers. In the newer videos, I use the JBC NASE-1B. Check the description with links on where to buy.
iphone 6 display connect damage
hi