Amiga.org

Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: RNSpeed on September 14, 2017, 03:12:32 PM

Title: 1084 monitor Composite distorted
Post by: RNSpeed on September 14, 2017, 03:12:32 PM

This monitor have had this issue for a long time. It works with my A1200 on RGB without any issues but when I connect the Composite input the image gets distorted as the monitor gets hot.

At first I thought it was a capacitor problem so I ordered a  cap replacement kit and recapped the whole monitor pcb but the problem persist.

Any of you guys have had this issue before?

Here are some pictures;

RGB (DB9) No issues

(https://ece.uprm.edu/~raymond/Amiga/IMG_5573.JPG)

(https://ece.uprm.edu/~raymond/Amiga/IMG_5575.JPG)


Composite Issues

After 5 min

(https://ece.uprm.edu/~raymond/Amiga/IMG_5579.JPG)

After 15 min

(https://ece.uprm.edu/~raymond/Amiga/IMG_5584.JPG)

After 1/2 hour.

(https://ece.uprm.edu/~raymond/Amiga/IMG_5596.JPG)

Title: Re: 1084 monitor Composite distorted
Post by: Oldsmobile_Mike on September 14, 2017, 04:36:06 PM

Your pictures aren't showing up here.  Try using the normal forum attachment methods to attach files to your post.  Good luck!

Title: Re: 1084 monitor Composite distorted
Post by: RNSpeed on September 14, 2017, 04:40:45 PM

Here's the pictures, sorry

First Two are on RGB showing that its working. The last three are the distorted image

Title: Re: 1084 monitor Composite distorted
Post by: RNSpeed on October 08, 2017, 03:02:48 PM

Following up on the threat I discovered that the problem happens only when I connect any NTSC source, It doesn't happens with as PAL source.

NTSC source problem is present on Composite, SEP.,RGB
PAL source problem not present on Composite,SEP., RGB

So I changed the IC TDA4570 (NTSC Decoder) But the problem persist :angry:

Title: Re: 1084 monitor Composite distorted
Post by: RNSpeed on October 08, 2017, 03:08:23 PM

Heres a photo of the mainboard