Galaga- bluish green lines

tmlee1130

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And some mirroring toward bottom of the screen. I've cleaned the legs on all the chips in the video board side. I've not done anything to the monitor chasis ..as I believe this problem is on video logic.

Problem started when game went crazy checked voltage it was up to about 9v. Got it back down to 5.15v now I have the crazy lines and mirroring at bottom. Trying to post a pic but I'm on my phone....
 
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I've seen that caused by a few different chips... and bad resistor packs.

Video RAM (2147 or 2148), 74LS296 at 5B, Resistor pack near 5B, or a bad 74LS368 at location 3N.

RJ
 
Ok I'm going to try and replace those parts.. ill keep u updated! Ty for quick reply
 
I've seen that caused by a few different chips... and bad resistor packs.

Video RAM (2147 or 2148), 74LS296 at 5B, Resistor pack near 5B, or a bad 74LS368 at location 3N.

RJ

Ok.. the 74LS296 is actually 74LS298. Ive replaced 5B, the resister pack near 5B and Ive replaced 3N.

Im looking for 2 2148s. I hope I can find some as I really miss playing Galaga :)

Ty RJ for your advice so far on this.
 
if you have the old flat resistors packs like channel said replace them with updated ones.

you can't really start fixing it until all the old sockets and resistor packs are replaced. i ran his renew kit on my board and havent had 1 problem since.
 
Galaga renew kit aye? I think I will have to try and get one ordered.

Ty :)
 
How long did it take to install the kit?

Andrew

if you have the old flat resistors packs like channel said replace them with updated ones.

you can't really start fixing it until all the old sockets and resistor packs are replaced. i ran his renew kit on my board and havent had 1 problem since.
 
A LONG time. ;)

It has all new resistor packs and all new 24/28/40/42 pin sockets.
 
Im pretty sure that my problem is related to the 2148 chips. One of the chips gets very hot while the game is on. I moved the chip to the other socket and it got very hot there as well.

So.. anyone know where I can find 2 2148 chips?
 
Thank you! I cannot wait to get this dang game going! GALAGA RULES :)
 
Well I found some 2148s today. I put them in and wahlah! a nice working galaga.

I still have one problem. The bugs that turn into like.. the specials say.. they scorpions or the green and white glider looking things, Those sprites are broken up. Does anyone know which chip runs these?

I also want to thank you all for the help on this, I appreciate it alot.

Todd
 
It won't. The self-test runs on every power up.

Clean the legs on the custom chips. The game will do strange things thanks to bad resistor packs, tarnished chip legs, and crappy sockets.

RJ
 
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