batsugun video problems--> looking for 74HCT273 chips

[brendz]

my batsugun has developed a video problem. It seems when enemy spites come onscreen they have solid color "trails" and random other parts have color trails such as parts of the select screen and some weapon fire seems to do it too. Also when there are no moving sprites the color palate seems a bit off like its missing a texture layer of something.

My troubleshooting so far has been tried in 4 different cabs with both special and normal roms. All have same problem. Ive tried pushing most chips but have noticed no differences. The cab it originally went funny in had a slightly high voltage of 5.14. I dialed it back and no difference.

Ive got some pics. Ill put them up after I get them uploaded.

Hopefully someone has some ideas/infos. I have a multimeter and soldering skills if need be.

[rtw]

5.16 V should not be an issue.

It sounds like a RAM problem or a loose pin. While the board is powered run your fingernail down the pins on the SMD chips.

What does the setup test image look like ?

[brendz]

The color trails get worse with movement. On static screens it look pretty good except the colors a little off (like the character select).
If you need any specific pics let me know.

[rtw]

So you see the error on the static test screen as well ?

Did you try the fingernail trick ?

[Stefan_L]

Found a japanse webpage (blog) wich shows a Battle Garegga with similar problem:
http://garakuta.homelinux.org/~nosuke/d ... =6&n=1#6-1

Fix?
http://garakuta.homelinux.org/~nosuke/d ... 3&d=22&n=1

[brendz]

Whoa that totally looks similar. Can anyone translate? If its just switchin a chip I can do no prob.

[brendz]

bump for a translation

[antron]

http://translate.google.com/translate?h ... rmd%3Divns

[alamone]

Replacing the two 74HCT273 chips near the JAMMA connector fixed it for him

[brendz]

sweet, thanks guys. Anyone know if these are just standard ICs I can order from my electronics store? Or if theres a good online supplier of them.

[brendz]

Bumping this to see if anyone knows somewhere i can get 74HCT273 chips online that takes paypal? I wanna get this going again.

[Artemio]

Although it is based of the same architecture, the games don't have the exact same configuration or hardware when it comes to the TTL logic. I know it feels like a good idea to try it, but without diagnosing if they are really broken I wouldn't go and replace the 273 chips.

I would advice to diagnose it first. With a cheap logic probe (around 20-30 USD) you can figure out if these are defective. (http://www.amazon.com/Elenco-Electronic ... ogic+probe)

You can start by using these scans from: http://arcade.ym2149.com/pcb/toaplan.html

http://arcade.ym2149.com/pcb/toaplan/ba ... rtside.jpg
http://arcade.ym2149.com/pcb/toaplan/ba ... erside.jpg

Here I made a small start for where those 273's come and go to:



That way you can figure out beforehand if they are involved in some way with video. I recently repaired a batsugun PCB, but the issues it had were in the input (no button 3 for the special roms). Those were the 240s just behind the 273's you mention.

[system11]

They are involved with the video. Connector -> resistor array -> 273s. In fact if you look at the photos linked to above, you've got another example of a board which has had at least one of them replaced They're an octal flip-flop, it's not unusual to see them fail.

74HCT273s are easy to find, look on ebay.