¢VCS FUTURA¢¢7800 VIDEO MODIFICATION, Version-0.1¢¢by Ye Olde Atari 8-bit owner¢¢ The 7800's RF video is usually quite good, although units tend to suffer from a type of interference pattern on screen. Presented here is a mod to combat this RF/Audio interference.¢¢Tools required:¢¢Philips type screw driver¢small longnose pliers¢soldering iron & solder¢¢Parts required:¢¢1 x 220uf 16v electrolytic capacitor¢¢ At this point, having collected the necessary things for the mod, connect up your soldering iron.¢¢OPEN UNIT:¢¢ Turn your unit upside down, and with the screwdriver remove the five screws that hold your unit together and put them somewhere safe for reassembly. Turn your unit upright and simply lift off the top half of the case, and put it safely out of the way for reassembly. Now use your pliers to straighten out the metal tabs positioned all around the edge of the shielding. The tabs around the heatsink are a little fiddly if your pliers are not so small. Once the tabs are all done, lift off the top part of the shielding and store it away for reassembly. At this point you can tin your soldering iron.¢¢LOCATION FOR CAPACITOR:¢¢ See fig-1 below and follow explanation later.¢¢ | |¢ | RF |¢ | box |¢ | |¢ ---------¢ |- |||¢ |- RRR¢ |- |||¢ |-¢¢¢ | -R-¢-T -R-¢ | -R-¢¢(+)-C-(-)<--this capacitor is it.¢ |-------------------| NOTE:that the¢ | VLSI | polarity + & -¢ | | are in brackets¢ | C025xxx-xx |¢¢ First locate the 'VLSI' chip part number C025xxx-xx. This is somewhere below the RF box (where you plug in the TV lead for the TV signal). Just above the 'VLSI' chip is a capacitor, we shall solder our capacitor in parallel with this on the board.¢¢SOLDERING THE CAPACITOR:¢¢ Trim the two capacitor leads to fit over the capacitor on the board (but not so much that the soldering iron can not get under). Now position the capacitor with the leads trimmed over the one on the board, and check that the polarity is correct (positive lead to the right and the negative lead to the left). When you are ready you may apply the soldering iron and the solder to the two lead ends respectively, so you end up with both capacitors in parallel.¢¢REASSEMBLY:¢¢Refit the shielding.¢Refit the top part of the case.¢Turn over and rescrew the two halves together.¢¢ On connecting up your 7800, you will notice that those interference patterns no longer stand out from the rest of the RF fuzz on your screen.¢¢Any blunder(s) you make are of your own doing, so congratulations.¢
