Author Topic: I need some info from jdm-055 board  (Read 1591 times)

Offline knowsly

  • Chief squatting Hard
  • *
  • Posts: 12
  • Post quality +1/-0
  • Gender: Male
  • Acidmods User
I need some info from jdm-055 board
« on: June 25, 2019, 01:01:40 PM »
I have two bad board here so I cant check them correctly
in both if them, the red line is grounded. should be ?

what component it is in blue circle ?
what is the value of D+ and D- line ?

which pin is the source power of mediatek ic ?
whats the value of yellow cap?

many thanks




Offline RDC

  • Administrator
  • Around the block
  • *
  • Posts: 2609
  • Post quality +90/-2
  • Gender: Male
  • The CGnome Project
Re: I need some info from jdm-055 board
« Reply #1 on: June 25, 2019, 01:47:18 PM »
Red line should measure around 2ohms to ground with a good multimeter. It's the antenna.

Blue circled component is a common mode choke, ~3.4ohm.

No idea what 'value' you want for D+/D- lines. Measuring Ohms to ground, on a good controller, they will be around 1.5M each.

That Mediatek chip most likely has multiple power rails. I have not traced them all out.

The Yellow Cap is just decoupling, 1000nF.
Screwing up is one of the best learning tools, so long as the only thing you're not learning is how to screw up.

Offline knowsly

  • Chief squatting Hard
  • *
  • Posts: 12
  • Post quality +1/-0
  • Gender: Male
  • Acidmods User
Re: I need some info from jdm-055 board
« Reply #2 on: June 25, 2019, 10:04:10 PM »
thank you again sir


 

SMF spam blocked by CleanTalk
SimplePortal 2.3.5 © 2008-2012, SimplePortal