Badcaps.net Forum
Go Back   Badcaps Forums > Troubleshooting Hardware & Devices and Electronics Theory > Troubleshooting Power Supplies and Power Supply Design
Register FAQ Calendar Search Today's Posts Mark Forums Read

 
Thread Tools Display Modes
Old 05-03-2022, 06:21 AM   #1
Beeldbuisje
Member
 
Join Date: Jul 2020
City & State: Mechelen
My Country: Belgium
I'm a: Knowledge Seeker
Posts: 55
Default How does an USB-C charger switches on?

A common USB-C charger seems not to give 5V when he's not connecting to an appliance. When connected, it starts with 5V and goes up to the tension needed.

In my case I'm working on a Apple A1707 macbook, with defective CD3215 chips.
On one port that previously worked, my charger doesn't switch on.

But what makes this charger to switch on. Does it has to sense a load, or does it require data on some line, or how...

Seems to be a mystery. Hopefully someone can explain this.
Beeldbuisje is offline   Reply With Quote
Old 05-04-2022, 02:09 PM   #2
sam_sam_sam
Badcaps Veteran
 
Join Date: Jul 2011
City & State: Some times Sunny Jacksonville FL
My Country: USA
Line Voltage: 120 Volts 60 HZ
I'm a: Knowledge Seeker
Posts: 3,653
Default Re: How does an USB-C charger switches on?

I am not exactly sure what makes it change what I do know is that it has a ic chip that selects the voltage voltage when it conditions are correct and met
__________________
9 PC LCD Monitor
6 LCD Flat Screen TV
30 Desk Top Switching Power Supply
10 Battery Charger Switching Power Supply for Power Tool
6 18v Lithium Battery Power Boards for Tool Battery Packs
1 XBox 360 Switching Power Supply and M Board
25 Servo Drives 220/460 3 Phase
6 De-soldering Station Switching Power Supply 1 Power Supply
1 Dell Mother Board
15 Computer Power Supply
1 HP Printer Supply & Control Board * lighting finished it *


These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
2 Hem Saw Computer Stack Board

All of these had CAPs POOF
All of the mosfet that are taken out by bad caps
sam_sam_sam is offline   Reply With Quote
Old 05-04-2022, 08:29 PM   #3
keeney123
Lauren
 
Join Date: Sep 2014
City & State: North Adams MA
My Country: United States
Line Voltage: 120VAC, 60Hz
I'm a: Knowledge Seeker
Posts: 2,414
Default Re: How does an USB-C charger switches on?

Quote:
Originally Posted by Beeldbuisje View Post
A common USB-C charger seems not to give 5V when he's not connecting to an appliance. When connected, it starts with 5V and goes up to the tension needed.

In my case I'm working on a Apple A1707 macbook, with defective CD3215 chips.
On one port that previously worked, my charger doesn't switch on.

But what makes this charger to switch on. Does it has to sense a load, or does it require data on some line, or how...

Seems to be a mystery. Hopefully someone can explain this.
This might help you

https://logi.wiki/index.php/CD3215_Bootup_Sequence

https://www.ti.com/power-management/...eyMatch=CD3215

and finally the TI data sheet for such a controller:
https://www.ti.com/lit/ds/symlink/tp...5%2526nr%253D1

Last edited by keeney123; 05-04-2022 at 08:50 PM..
keeney123 is offline   Reply With Quote
Old 05-05-2022, 11:19 AM   #4
Beeldbuisje
Member
 
Join Date: Jul 2020
City & State: Mechelen
My Country: Belgium
I'm a: Knowledge Seeker
Posts: 55
Default Re: How does an USB-C charger switches on?

The problem of the macbook is solved... Not repairable; there're lot of copper paths which becomes loose. Don't know what happened with this board, I've never seen this before.

Anyway, I figured out (thanks for the URL's) the importance of the CC pins. The data on this CC pins are responsible for selecting the output voltage.

But, measuring on VBUS or CC pins with disconnected charger, but charger plugged in in 230V AC, gives... nothing. Nor measured with scope, nor with multimeter.
The USB-C plugged in in a working Macbook let's see data transfer on CC pins.

But how it starts... I still can't find it anywhere.
Beeldbuisje is offline   Reply With Quote
Old 05-07-2022, 10:57 PM   #5
keeney123
Lauren
 
Join Date: Sep 2014
City & State: North Adams MA
My Country: United States
Line Voltage: 120VAC, 60Hz
I'm a: Knowledge Seeker
Posts: 2,414
Default Re: How does an USB-C charger switches on?

Quote:
Originally Posted by Beeldbuisje View Post
The problem of the macbook is solved... Not repairable; there're lot of copper paths which becomes loose. Don't know what happened with this board, I've never seen this before.

Anyway, I figured out (thanks for the URL's) the importance of the CC pins. The data on this CC pins are responsible for selecting the output voltage.

But, measuring on VBUS or CC pins with disconnected charger, but charger plugged in in 230V AC, gives... nothing. Nor measured with scope, nor with multimeter.
The USB-C plugged in in a working Macbook let's see data transfer on CC pins.

But how it starts... I still can't find it anywhere.
Your chip I have no idea how that starts as I can not find detailed specs like TI. With the TI TPS65983B, which is the bottom url link I supplied, on page 27 is parameter measurement wave forms and the line of time for UVR_out3V3. All those things have to happen in order to have the chip to work. It then goes on to explain in detailed on page 29 its workings. On page 30 is the internal block diagram. The digital core has Analog to digital convertors. I have not read all the way though this link. However, I would imagine that there are encoders in the output of the Digital Core to the Port Data Multiplexer that combine with the input/output lines of the Port Data Multiplexer to determine what and when something is written on those lines either to the USB-C or back to the computer.

Last edited by keeney123; 05-07-2022 at 11:19 PM..
keeney123 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



Badcaps.net Technical Forums 2003 - 2022
Powered by vBulletin ®
Copyright ©2000 - 2022, Jelsoft Enterprises Ltd.
All times are GMT -6. The time now is 12:25 PM.
Did you find this forum helpful?