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 08-16-2020, 05:57 AM   #1
pintglass
Member
 
Join Date: Jul 2019
City & State: Congleton
My Country: United Kingdom
I'm a: Knowledge Seeker
Posts: 75
Default Powerline Network Adapter power Issue

Hi
Im trying to repair a D-Link(DHP-300AV) powerline adapter which is not powering up.

I've only done some basic tests at the moment to confirm its getting mains in through the fuse which it is. All caps dont show any sign of buldging.
The power supply seems to be based around a LNK623PG as can be seen in the images attached.

Can anyone provide any trouble shooting steps to try and diganose whats causing the no power issue.
Attached Images
File Type: jpg IMG_0062.jpg (219.5 KB, 31 views)
File Type: jpg IMG_0064.jpg (246.2 KB, 25 views)
pintglass is offline   Reply With Quote
Old 08-16-2020, 06:15 AM   #2
Per Hansson
Super Moderator
 
Per Hansson's Avatar
 
Join Date: Jul 2005
City & State: ----
My Country: Sweden
Line Voltage: 230v 50Hz
I'm a: Knowledge Seeker
Posts: 5,138
Default Re: Powerline Network Adapter power Issue

You can look at the datasheet of the LNK623PG to get an idea.
But with these units running as hot as they usually do they often bake the capacitors.
So just replacing them without much other tests might be worth it.
Or just throw it is the trash: I hate these devices with a passion.
They pollute the radio spectrum so much that even regular FM broadcasts are affected.
Nevermind AM or short wave, I never understood how these get FCC approval!
__________________
"The one who says it cannot be done should never interrupt the one who is doing it."
Per Hansson is offline   Reply With Quote
Old 08-25-2020, 03:16 PM   #3
pintglass
Member
 
Join Date: Jul 2019
City & State: Congleton
My Country: United Kingdom
I'm a: Knowledge Seeker
Posts: 75
Default Re: Powerline Network Adapter power Issue

I agree I should just throw this away, but my curiousity gets the better of me at times.
Just out of interest on page 4 of the datasheet for the LNK623 it shows a reference design schematic with the feedback winding on the secondary side of the transformer but in the output regulation section of text it says
"The output voltage is sensed using a primary referenced winding on transformer T1 eliminating the need for an optocoupler and a secondary sense circuit"
Does this mean the reference is on the primary side?

I've attached the page of the datasheet for reference.
Attached Files
File Type: pdf lnk623 page 4.pdf (490.4 KB, 3 views)
pintglass is offline   Reply With Quote
Old 08-29-2020, 02:29 AM   #4
Per Hansson
Super Moderator
 
Per Hansson's Avatar
 
Join Date: Jul 2005
City & State: ----
My Country: Sweden
Line Voltage: 230v 50Hz
I'm a: Knowledge Seeker
Posts: 5,138
Default Re: Powerline Network Adapter power Issue

No it means it can perform regulation without any "real" (expensive) sense logic.
But you do have an optocoupler on your device (U8) so might not follow the reference design.
That said I was unable to trace where it goes so maybe it is for something else.
In your seat I would replace the caps, Acon is a shit brand and it would not be uncommon for them to fail.
But if you want to do some checks just see what output voltage you have on the LNK chip, and on the caps and see if it makes sense.
Per Hansson is offline   Reply With Quote
Old 09-02-2020, 06:04 PM   #5
budm
Badcaps Veteran
 
budm's Avatar
 
Join Date: Feb 2010
City & State: S.F. Bay area
My Country: USA
Line Voltage: 120V 60Hz
I'm a: Knowledge Seeker
Posts: 39,206
Default Re: Powerline Network Adapter power Issue

https://www.badcaps.net/forum/attach...8&d=1597579006

Did you check resistor R5 (624) to see if its resistance has gone up?
That resistor and the Diode PD8 look to be for Brown protection that will shutdown the LNK via OPTO.
__________________
Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956

Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999

Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl

Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/

TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
budm is offline   Reply With Quote
Old 09-07-2020, 03:40 PM   #6
pintglass
Member
 
Join Date: Jul 2019
City & State: Congleton
My Country: United Kingdom
I'm a: Knowledge Seeker
Posts: 75
Default Re: Powerline Network Adapter power Issue

Quote:
Originally Posted by budm View Post
https://www.badcaps.net/forum/attach...8&d=1597579006

Did you check resistor R5 (624) to see if its resistance has gone up?
That resistor and the Diode PD8 look to be for Brown protection that will shutdown the LNK via OPTO.
I've checked the resistor and it seems fine giving a reading of 619 K ohm's
pintglass 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 11:10 PM.
Did you find this forum helpful?