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View Full Version : Lunar Lander Repair help needed



dezbaz
8th August 2009, 11:17 PM
Hi Guys

I have a semi working LL PCB

I have 1 extra diagonal line 3" long that doesn't belong, and the screen is jumpy.

I am going to replace a few sockets first, but may need some help after that.

This will be a bit similar to an asteroids board

(The cab is tested, on an asteroids PCB and checks out by the way)

Anyone got any ideas?
Thanks

dezbaz
9th August 2009, 10:21 PM
I found this info, may be similar fix here (http://www.ionpool.net/arcade/asteroidtech/asteroidsrepair.html#V10) (Thanks Daics for the link)

10. Problem: Diagonal line emanating from one asteroid.

Fix: Use a faster EPROM (300ns) for location N/P3.

11. Problem: Display only visible in a very narrow vertical band in centre of screen, some activity can just be seen in the band (revision 04 board).

Fix: TL082 op amp at C12 had been removed, as well as the two capacitors at C98 and C119 (220 pf radial lead epoxy dipped 100V Mica capacitors). Replaced.

12. Problem: Onscreen objects and text consistently flick between normal size and about four times larger, also extra spurious lines and explosions.

Fix: Replaced LS175N at M7 ? pin 6 was stuck high, pin 7 was stuck low

13. Problem: Game played but nothing on the screen except for a general glow that varied as the game was played blind, X and Y outputs were erratic

Fix: 7915CT voltage regulator at VR2 was bad ? replaced

14. Problem: Corrupt graphics ? in game mode all graphics were split down the middle (horizontally) and the two halves were then drawn besides each other. In test mode, only two vertical lines and a diagonal line were visible (revision 04 board)

Diagnosis: Pin 11 of the 74LS32 at B9 was stuck High, but replacing this IC didn?t fix the problem. This is the LDSTROBE signal that connects to pin 11 of the 74LS191?s at C9 up to J9, which were all of course also High. Used a logic comparator and saw that this highlighted the 191 at C9 as being faulty

Fix: Replaced 74LS191 at C9

serviceit
9th August 2009, 10:38 PM
nice find, another one for bookmarking.

Ando77
10th August 2009, 08:23 PM
Well Done Dez !

LL is a Classic ;)

Johns-Arcade
10th August 2009, 08:40 PM
I'm happy to look at your PCB if needed Dez.

Regards,

Johns-Arcade.

dezbaz
10th August 2009, 09:06 PM
I'm happy to look at your PCB if needed Dez.

Regards,

Johns-Arcade.

That would be fantastic John, Thank you

I accept your kind offer.

I still have your address, so I'll box it up and send it off.

Cheers mate

PS Do you know who changed my sub-title under my user name? LOL

Johns-Arcade
10th August 2009, 09:46 PM
That would be fantastic John, Thank you

I accept your kind offer.

I still have your address, so I'll box it up and send it off.

Cheers mate

PS Do you know who changed my sub-title under my user name? LOL

No problem mate, it may take me a little while to get to it (as usual :laugh:).

No mate, I don't know who changed your sub-title and only noticed it when you pointed it out :lol

Cheers!

Johns-Arcade.

dezbaz
11th August 2009, 09:39 PM
It was Daics, the scalliwag 5000 vbux less in his wallet LOL

Hey John
Can I send you my Battlezone PCBs in the package for testing also?

The red lights come on but a black screen is present. . .

It would be nice to rule that out, (if possible)

Johns-Arcade
11th August 2009, 10:25 PM
It was Daics, the scalliwag 5000 vbux less in his wallet LOL

Hey John
Can I send you my Battlezone PCBs in the package for testing also?

The red lights come on but a black screen is present. . .

It would be nice to rule that out, (if possible)

That's fine Dez, send them over.

Cheers!

Johns-Arcade.

Davefjedi
12th August 2009, 07:40 AM
When this baby is going cant wait to see it. dezbaz this has to be one of my fav games such a simple idea but so challenging after 20 pots :) there is nothing better then playing this on a nice monitor all white and crispy ohhh just gave myself goose bumps :rolleyes
John nice offer to have a look at it :023:

dezbaz
12th August 2009, 08:54 AM
When this baby is going cant wait to see it. dezbaz this has to be one of my fav games such a simple idea but so challenging after 20 pots :) there is nothing better then playing this on a nice monitor all white and crispy ohhh just gave myself goose bumps :rolleyes
John nice offer to have a look at it :023:

The offer is still there, when it's finished Dave ;)

dezbaz
21st February 2016, 09:27 AM
I swapped everything else, IE: from the game board, the chassis, the power brick, regulator

It ended up being the yoke, on the monitor

Johns-Arcade
21st February 2016, 11:23 AM
I swapped everything else, IE: from the game board, the chassis, the power brick, regulator

It ended up being the yoke, on the monitor

I had to re-read the whole post to remember the problem Dez. :)

Do you have a spare yoke?

Regards,

Johns-Arcade.

Davefjedi
22nd February 2016, 06:21 AM
Holy crap 2009 to 2016 are you sure your not on contract ?????:lol