Jump to content

Photo

Colecovision video corruption/ l14 inductor questions


10 replies to this topic

#1 Yjzep OFFLINE  

Yjzep

    Space Invader

  • 21 posts
  • Location:Southington, CT

Posted Wed Jan 31, 2018 11:35 AM

Hi all!  I am fixing a colecovision with a corrupted display issue.  It will work great forever, until I power it off for a few minutes.  On start, it will boot to a corrupted screen and degrade to unstable noise.  The power supply i fine, I get good supply at the switch rails so it's not that.  Here's the rub.  If I push down on L-14 in this state, it will correct.  Once it "stabilizes", it will continue to work indefinitely, as long as I dont take any breaks.  I played 2600 on the module 1 for 3 hours last night.  

Any ideas, and also if it is l14 (believe it's a 2.7uh inductor in the video circuit), where can I find one?  google only shows me completely different form factors.

T.I.A.!

Yjzep


Edited by Yjzep, Wed Jan 31, 2018 11:36 AM.


#2 Hatta OFFLINE  

Hatta

    Stargunner

  • 1,342 posts

Posted Wed Jan 31, 2018 11:38 AM

Have you tried reflowing the solder on l14?



#3 Yjzep OFFLINE  

Yjzep

    Space Invader

  • Topic Starter
  • 21 posts
  • Location:Southington, CT

Posted Wed Jan 31, 2018 11:39 AM

Also, yes I checked and touched up the solder.  Either the part is janky or its something else.  Once it works, jiggling it does nothing to corrupt it.



#4 Yjzep OFFLINE  

Yjzep

    Space Invader

  • Topic Starter
  • 21 posts
  • Location:Southington, CT

Posted Wed Jan 31, 2018 11:41 AM

It's almost like it needs to "warm up"



#5 Yjzep OFFLINE  

Yjzep

    Space Invader

  • Topic Starter
  • 21 posts
  • Location:Southington, CT

Posted Wed Jan 31, 2018 12:03 PM

It's the brown fella right in the middle on the right side of the board.

Attached Thumbnails

  • 20180131_130030.jpg
  • 20180131_130027.jpg


#6 Yjzep OFFLINE  

Yjzep

    Space Invader

  • Topic Starter
  • 21 posts
  • Location:Southington, CT

Posted Wed Jan 31, 2018 6:19 PM

Confirmed the warmup theory. Twice today I leery it sit powered on and corrupted and about 8 minutes later it stabilized. Benn playing an hour, switching games and using the 2600 module, no issues.

#7 grips03 OFFLINE  

grips03

    River Patroller

  • 3,508 posts
  • Location:New England

Posted Wed Jan 31, 2018 7:53 PM

newark.com

digikey.com

mouser.com

 

are the places I buy parts from



#8 Yjzep OFFLINE  

Yjzep

    Space Invader

  • Topic Starter
  • 21 posts
  • Location:Southington, CT

Posted Thu Feb 1, 2018 9:40 AM

newark.com

digikey.com

mouser.com

 

are the places I buy parts from

thanks, I used mouser and digikey before..

I guess what Im asking is since I'm a hack engineer, I don't have much experience with inductors.  I know what they are, but there are different types.  None of the ones offered at those sites have the same form factor as the one im replacing.  Is the 2.7uh the only measurement that matters?  axial or radial?  The ones that look like oversized fat resistors ok?  


Edited by Yjzep, Thu Feb 1, 2018 9:41 AM.


#9 grips03 OFFLINE  

grips03

    River Patroller

  • 3,508 posts
  • Location:New England

Posted Thu Feb 1, 2018 3:45 PM

yes, any 2.7uh.  Just make sure it fits, which should be pretty easy.  Perhaps match up the DC resistance as well.



#10 grips03 OFFLINE  

grips03

    River Patroller

  • 3,508 posts
  • Location:New England

Posted Thu Feb 1, 2018 8:09 PM

if you want I can mail you a spare one.  send me pm.



#11 Yjzep OFFLINE  

Yjzep

    Space Invader

  • Topic Starter
  • 21 posts
  • Location:Southington, CT

Posted Fri Feb 2, 2018 4:47 PM

if you want I can mail you a spare one.  send me pm.

Ill let you know if I strike out, but your help was all I really wanted!  This site is awesome, thanks for helping to keep the old machines going!






0 user(s) are browsing this forum

0 members, 0 guests, 0 anonymous users