VG-8020 green screen

Supporter (2)

19-09-2019, 09:52

Hallo!!

I got an Philips VG-8020 and in general it work. Only the color on the screen is starange ... on my screen I get a yellow/green color instead of blue background. Welcome screen and Basic works fine ...
Color statement change the green level (from high to low).
It looks like I connect the computer to a screen monitor but it's a normal TV. I see this on the monitor interface and on the antenna. So I guess it's something internal signal which is not correct.
Can someone gave me a link where I have to search board to fix it ? Is it directly the TI chip or the PAL converter?

Ps.: I'm new on MSX, so possible I have done something stupid ...

thanks
Juergen

By zett

Hero (608)

19-09-2019, 13:38

if you did it by composite conector(small yellow plug) than the cable is wrong. it got a green output and a fullcollor

By zett

Hero (608)

19-09-2019, 13:44

8 pin DIN

---7-------6

3-----8-----1

---5-------4
-------2

1 +5V
2 gnd ('luminance')
3 AUDIO
4 Ys (monochrome)
5 CVBS (color video PAL)
6 +12V
7 NC
8 NC

By sdsnatcher73

Prophet (3956)

19-09-2019, 14:09

Well as you mentioned you have the same issue on antenna / RF it is unlikely it has something to do with the cable(s). Where do you live, is your TV PAL capable? If it is than I think the encoder chip on your VG8020 is dying, it encodes the signals from the VDP into a PAL composite signal.

By Bobo

Supporter (2)

19-09-2019, 21:07

Yep , I'm in Germany so PAL region. So it seems its not easy to get a PAL encoder replacement. Any hints from the comunity?

By sdsnatcher73

Prophet (3956)

19-09-2019, 22:46

I only now noticed your Name in the first post, that should have tipped me off

Anyway, ask Repair-Bas or Omega on this forum. I am sure they will be able to provide the chip or help you purchase it somewhere.

By l_oliveira

Hero (534)

08-10-2019, 14:16

Before condemning the PAL encoder board, consider checking/replacing the 4.43Mhz oscillator cristal. As it is mechanically fragile and can also be damaged by XRAY from being sent through mail or airport security (it is a 1x oscillator, any changes caused by xray will cause it to change frequency enough to cause problems) it's worth trying to replace it.

By Omega

Master (233)

09-10-2019, 14:09

It has the LVA510 chip, which has different failure modes: no picture at all or picture with wrong colors. I think I have one more in stock, cost is about 5€.

By amsmc2

Supporter (1)

14-02-2023, 10:32

HI @Bobo
I have the same problem, and I would like to know if you have been able to solve it.

Thanks

By Wierzbowsky

Guardian (3603)

14-02-2023, 19:13

Replacing this bloody LVA510 usually solves no/bad video problems. But buying them is a lottery. I usually get 33% bad/fake chips from China in every batch.