Badcaps.net Forum
Go Back   Badcaps Forums > Troubleshooting Hardware & Devices and Electronics Theory > Equipment Usage, Soldering, Techniques, and Reviews
Register FAQ Calendar Search Today's Posts Mark Forums Read

 
Thread Tools Display Modes
Old 04-30-2021, 12:47 AM   #81
gabiz_ro
Senior Member
 
Join Date: Mar 2011
City & State: Bacau
My Country: Romania
Line Voltage: 230V 50Hz
I'm a: Hobbyist Tech
Posts: 159
Default Re: New tool to find short capacitors on motherboards : shorty with display

Quote:
Originally Posted by kripton2035 View Post
I received the pcb some times ago. but there is a failure I did not find until now.
I made some changes in the schematic, using a constant current source for better repetability,
well I'm still investing. the voltage regulator is giving 2.4V instead of 5V
... and it does not seems to be a short circuit !
Some more info about?
I mean about voltage regulator.
gabiz_ro is offline   Reply With Quote
Old 04-30-2021, 02:21 AM   #82
stj
Great Sage 齊天大聖
 
stj's Avatar
 
Join Date: Dec 2009
City & State: Europe
My Country: some shithole run by Israeli agents
I'm a: Professional Tech
Posts: 25,390
Default Re: New tool to find short capacitors on motherboards : shorty with display

do you mean your not getting enough current from the one on the arduino?
that doesnt surprise me really.
you probably need to use a 1A linear regulator and some tantalum caps
stj is offline   Reply With Quote
Old 04-30-2021, 03:13 AM   #83
kripton2035
Member
 
kripton2035's Avatar
 
Join Date: Mar 2014
City & State: Europe (France)
My Country: France
Line Voltage: 230VAC 50Hz
I'm a: Hobbyist Tech
Posts: 31
Default Re: New tool to find short capacitors on motherboards : shorty with display

I added a voltage regulator 1755S to bypass the one inside the arduino. just thinking there would be a better regulation than the 1117. I also added a constant current source with the pnp transistor, to have better accuracy and better reproductibility of the measures.
now I'm debugging this new schematic, it's almost working, but as a reminder it is a hobby project, and I have been very busy these last months.
kripton2035 is offline   Reply With Quote
Old 04-30-2021, 03:41 AM   #84
gabiz_ro
Senior Member
 
Join Date: Mar 2011
City & State: Bacau
My Country: Romania
Line Voltage: 230V 50Hz
I'm a: Hobbyist Tech
Posts: 159
Default Re: New tool to find short capacitors on motherboards : shorty with display

I was more about

Quote:
I'm still investing. the voltage regulator is giving 2.4V instead of 5V
As I see 1755S is limited to 300mA
Aprox 60mA via Q1 and resistors, 240mA for Arduino, oled and others.
gabiz_ro is offline   Reply With Quote
Old 04-30-2021, 06:52 AM   #85
kripton2035
Member
 
kripton2035's Avatar
 
Join Date: Mar 2014
City & State: Europe (France)
My Country: France
Line Voltage: 230VAC 50Hz
I'm a: Hobbyist Tech
Posts: 31
Default Re: New tool to find short capacitors on motherboards : shorty with display

I checked on a lab power supply, the whole device is now using 50-60mA.
the current constant source now is using 30mA.
kripton2035 is offline   Reply With Quote
Old 04-30-2021, 09:47 AM   #86
gabiz_ro
Senior Member
 
Join Date: Mar 2011
City & State: Bacau
My Country: Romania
Line Voltage: 230V 50Hz
I'm a: Hobbyist Tech
Posts: 159
Default Re: New tool to find short capacitors on motherboards : shorty with display

Some schematic will help a lot.
Where did you get 2.4V instead of 5V with voltage regulator?
Also
Voltage drop C-E on BC557 at 100 mA is in datasheet 0.65V
5V -Vdrop on BC557 = 4.35V
4.35V on 82 + 2 +1 ohms is around 0.051A that is 51mA but since it may be pulsing lab power supply will show some intermediate value.

I'm not so familiar with Arduino but in source code seems like you defined TRANSISTOR and BUTTON both to pin 3
gabiz_ro is offline   Reply With Quote
Old 05-01-2021, 12:41 PM   #87
kripton2035
Member
 
kripton2035's Avatar
 
Join Date: Mar 2014
City & State: Europe (France)
My Country: France
Line Voltage: 230VAC 50Hz
I'm a: Hobbyist Tech
Posts: 31
Default Re: New tool to find short capacitors on motherboards : shorty with display

Quote:
I'm not so familiar with Arduino but in source code seems like you defined TRANSISTOR and BUTTON both to pin 3
transistor is on an analog pin 3 A3, and button on a digital pin 3 D3
they are not the same pin.
anyway, the transistor is always on, and has been removed from the source code when I use the constant current source.
kripton2035 is offline   Reply With Quote
Old 05-01-2021, 12:43 PM   #88
kripton2035
Member
 
kripton2035's Avatar
 
Join Date: Mar 2014
City & State: Europe (France)
My Country: France
Line Voltage: 230VAC 50Hz
I'm a: Hobbyist Tech
Posts: 31
Default Re: New tool to find short capacitors on motherboards : shorty with display

this is the actual state of the schematic of the shorty-with-display input stage.
Attached Images
File Type: png shorty 05-2021.png (54.8 KB, 45 views)
kripton2035 is offline   Reply With Quote
Old 05-02-2021, 12:10 AM   #89
gabiz_ro
Senior Member
 
Join Date: Mar 2011
City & State: Bacau
My Country: Romania
Line Voltage: 230V 50Hz
I'm a: Hobbyist Tech
Posts: 159
Default Re: New tool to find short capacitors on motherboards : shorty with display

Are both 3 but must be something to differentiate.
For digital pin you can define simple with number only but for analog inputs you need to specify is analog one by using A prefix.
gabiz_ro is offline   Reply With Quote
Old 06-05-2021, 02:43 AM   #90
dicky96
Sun Seeker
 
dicky96's Avatar
 
Join Date: Mar 2017
City & State: Sunny Gran Canaria
My Country: Spain
Line Voltage: 220V 50Hz
I'm a: Professional Tech
Posts: 1,254
Default Re: New tool to find short capacitors on motherboards : shorty with display

Hi Kripton
Do you have any up to date news regarding the PCB?
__________________
Follow me on YouTube
------------------
Learn Electronics Repair
https://www.youtube.com/channel/UCFX...R8UZ2vg/videos
dicky96 is offline   Reply With Quote
Old 06-05-2021, 02:01 PM   #91
clearchris
Badcaps Veteran
 
clearchris's Avatar
 
Join Date: Dec 2013
City & State: San Antonio
My Country: United States
Line Voltage: 120v 60hz / 240v 60hz
I'm a: Hardcore Geek
Posts: 542
Default Re: New tool to find short capacitors on motherboards : shorty with display

Quote:
Originally Posted by dicky96 View Post
Do you have any up to date news regarding the PCB?
He has been busy with work. I have considered building one from the schematic, but it's not enough of a priority for me to drag out the perf board.

I am getting the LCD on order though.
clearchris is offline   Reply With Quote
Old 06-05-2021, 02:51 PM   #92
stj
Great Sage 齊天大聖
 
stj's Avatar
 
Join Date: Dec 2009
City & State: Europe
My Country: some shithole run by Israeli agents
I'm a: Professional Tech
Posts: 25,390
Default Re: New tool to find short capacitors on motherboards : shorty with display

it's an OLED - get a selection of white, blue and mixed colour.
i wish they sold them in green - it would look like an old crt
stj is offline   Reply With Quote
Old 06-05-2021, 03:56 PM   #93
clearchris
Badcaps Veteran
 
clearchris's Avatar
 
Join Date: Dec 2013
City & State: San Antonio
My Country: United States
Line Voltage: 120v 60hz / 240v 60hz
I'm a: Hardcore Geek
Posts: 542
Default Re: New tool to find short capacitors on motherboards : shorty with display

Quote:
Originally Posted by stj View Post
it's an OLED - get a selection of white, blue and mixed colour.
i wish they sold them in green - it would look like an old crt
I have this one in my cart. Not sure I want to go back to the old days with a choice of monochrome green or monochrome amber. I don't miss that at all.

https://www.aliexpress.com/item/3280...c00gcT6Vz&mp=1
clearchris is offline   Reply With Quote
Old 08-12-2021, 09:17 AM   #94
aneng
New Member
 
Join Date: Dec 2014
City & State: SWANSEA
My Country: United Kingdom
I'm a: Knowledge Seeker
Posts: 15
Default Re: New tool to find short capacitors on motherboards : shorty with display

@Kripton2035

Hi Kripton.... it's August now !! Please say you have more information on the PCB supply - or anything about this project. I can't wait to build one !
aneng is offline   Reply With Quote
Old 08-13-2021, 07:02 PM   #95
clearchris
Badcaps Veteran
 
clearchris's Avatar
 
Join Date: Dec 2013
City & State: San Antonio
My Country: United States
Line Voltage: 120v 60hz / 240v 60hz
I'm a: Hardcore Geek
Posts: 542
Default Re: New tool to find short capacitors on motherboards : shorty with display

Quote:
Originally Posted by aneng View Post
@Kripton2035

Hi Kripton.... it's August now !! Please say you have more information on the PCB supply - or anything about this project. I can't wait to build one !
My LCD for this project just arrived today, it's much smaller than I thought it would be. This project should be able to fit on some perfboard. If you want to build it on some perfboard, I'll go along. Last I heard there was one last issue, and kripton was busy at work. I'm sure he will come back when he's through.

Want to work through the last issue?
clearchris is offline   Reply With Quote
Old 09-11-2021, 04:43 AM   #96
h0baz
New Member
 
Join Date: Sep 2021
City & State: Seiun
My Country: اليمن
I'm a: Knowledge Seeker
Posts: 3
Default Re: New tool to find short capacitors on motherboards : shorty with display

nice job..
h0baz is offline   Reply With Quote
Old 10-18-2021, 10:07 AM   #97
paulyboy
New Member
 
Join Date: Mar 2020
City & State: auckland
My Country: New Zealand
I'm a: Knowledge Seeker
Posts: 18
Default Re: New tool to find short capacitors on motherboards : shorty with display

Any progress?
paulyboy is offline   Reply With Quote
Old 10-18-2021, 12:05 PM   #98
stj
Great Sage 齊天大聖
 
stj's Avatar
 
Join Date: Dec 2009
City & State: Europe
My Country: some shithole run by Israeli agents
I'm a: Professional Tech
Posts: 25,390
Default Re: New tool to find short capacitors on motherboards : shorty with display

not here - maybe check the thread at eevblog?
stj 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 - 2021
Powered by vBulletin ®
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
All times are GMT -6. The time now is 11:39 PM.
Did you find this forum helpful?