G05 801 deflection board problem

virtvic

Member
Joined
Feb 25, 2007
Messages
68
Reaction score
0
Location
Glasgow
The vectors on my upright asteroids seem to have a 'bumpy' look to them when a graphic trvels over the screen. It's too subtle to pick up on camera.

The lines are sort of jagged and when I put the game in test mode, the cross hatch is 'bowed' rather than diagonal lines. The game runs just fine, just looks a bit crappy.

I recently pulled a deflection board from a friend's Asty and it cleared up all the problems on mine, so I KNOW it's just the deflection board problem.

I did a bit of comparing and the resistors at R621 and R721 on mine are the correct value at 6.8k ohm and his are both 3.3k - and his is better than mine - what the heck?

Also, some of the transistors on mine have been replaced in the past with bigger, upright transistors, rather than the lay down flat, held down with a nut type.
 
Bump - any help guys?

here is a pic of my deflection pcb, with some of the (maybe) suspects parts...
 

Attachments

  • IMAG0140.jpg
    IMAG0140.jpg
    101 KB · Views: 16
The blue circled transistors are original. The 2 red ringed ones are the same as the blue ones on my mate's pcb. The green ones are also the same, but without the black heatsinks on my mates pcb.

All the transistors on my mate's pcb are the smaller bolted down type.

The cyan ringed resistors are the 6.8k ohms, whereas my mate's pcb has 3.3k ohms (not correct according to the parts list)
The purple ringed cap is a 47 uf (normal cap) whereas the original is a 45 uf low esr cap.

Hope this helps someone to help me!
 
Back
Top Bottom