Aliens HELP anyone ?

[TheDaddy]

Hey all , So it been 2 years since I picked up my soldering gun and 2 boards are giving me grief as usual !!!

So I have never done an Aliens PCB repair and am struggling a bit with the shcematics. I am probably just having a blond moment maybe but my head is mashed and wondered if anyone can help ??

So I am getting a Green screen a constant " Beep " from the speakers :-


So i have had a poke around and the game is not resetting but as there is nothing on the screen I am assuming the game program is running. I have tried to check the ram at G21 as the input is high and it the W/R so I would assume the should be active low ?? Anyway below the schematic for pin 27 (R/W) NWR 01C4 - Where the hell is that ??? I have Address line input but no Output so wondering if to just pull the chip.



Am i just being a knob ?? I am getting totally confused with this !! I didnt want to just shotgun but unsure what else to do.

This damn board is pebbled with Fujitsu chips , And being a Konami its cutting the legs to desolder and the boards are a nightmare.

Not having a good , Any help appreciated as always.

Dave.

P.S I wish I had purchased the Slice for sale the other day ............

EDIT :- Just tested and I am only getting green , No red or blue. I reckon if I restore that I should get the test screen info.

 

[Flyback2021]

Hi Dave
Think I have the original manual with schematics for Aliens, do you need anything screenshot or copied ?
Have a working one and one without sound but not had a chance to get to the bottom of it yet.
cheers Ant

 

[TheDaddy]

Hi Ant , I just dont know what going on with it at all if I am honest. I get the green screen and a "Beep Beep Beep" constant from the speakers. I dont have any Red or Blue so unsure if behind the green there may be the actual errors. Going round in circles as you do ! lol. The customs look ok but I am never sure with them , I have replaced the 2 x Custom PAL chips (Thanks to Caius) but no change. Thats controls all the R/W and CE to the chips. The main 512 are all ok but nothing on the data lines of the 6264. Everything is toggling as far as I can tell everywhere else , In the places we would expect anyway.

Biggest issue (As I am sure you are aware !) is that Konami boards are a nightmare when it come to desoldering.

Flicking the Test switch makes no difference either, But unsure if there is an issue it will auto goto that screen ??

I am a little lost with this one at the minute , Its pebbled with damn Fujitsu chips as well. Cant find any reference to this in anyone else's repair logs either.

Its not even watchdogging so unsure if it would be a addressing issue.

Dave.

P.S I may have to get another board to use for reference !

 

[TheDaddy]

So I did a bit more on this , So after some checking discovered that there was a few (Fujitsu !) ls257's faulty @ D16 & E17. This has now restored the colours and I get :-



Then found a ls245 @ G19 and that failed , Removed and replaced. Still no change !

I am now getting towards the ShotGun phase , This is something I hate.

Any ideas before i grab my cowboy boots and get saddled up ? Lol.

Dave.

 

[big10p]

Looks more like The Matrix. Lol

 

[Ace`]

I've got two of these in the junk pile as the custom cpu is dead on both of them.

 

[TheDaddy]

I was worried it could be that Ace !! CPU was on my mind to be fair. Fingers crossed its not.

I have :-

1 x Aliens (This one - Faulty!)
2 x TMNT (One is battered as some one wrecked it with heat @ few rusty and broken legs on custom so will be used for spares , Other is giving me hell prety much same issues as Aliens. I have replaced the CPU on that and I was a little closer but on the 2 hard pile)
1 x Simpsons (Faulty) - Next on my list , Untouched as yet.

1 x Konami 88 - Replaced so much on this and still has issues !

I have come to realise that I HATE Konami boards with a passion !! Hard to remove and replace chips and so so difficult to diagnose. Most confusing boards ever. Oh and riddled with Fujitsu as well !!



AHHHHHHHHHH !

Dave.

 

[sukhbir]

So I did a bit more on this , So after some checking discovered that there was a few (Fujitsu !) ls257's faulty @ D16 & E17. This has now restored the colours and I get :-

View attachment 21796

Then found a ls245 @ G19 and that failed , Removed and replaced. Still no change !

I am now getting towards the ShotGun phase , This is something I hate.

Any ideas before i grab my cowboy boots and get saddled up ? Lol.

Dave.

What is the DTACK pin 9 on the custom CPU doing?if it's stuck high then the databus will be halted.

 

[Lurch666]

Sometimes a PCB won't watchdog even if the CPU isn't running so check for address and data activity on the CPU.
Then check Program roms and ram plus any LS chips between them.
I'm presuming the CPU has clock since you are getting graphics.
Then check the interrupts as they can mess with the CPU activity as well.

 

[TheDaddy]

Sometimes a PCB won't watchdog even if the CPU isn't running so check for address and data activity on the CPU.
Then check Program roms and ram plus any LS chips between them.
I'm presuming the CPU has clock since you are getting graphics.
Then check the interrupts as they can mess with the CPU activity as well.

Prety much replaced all the logic around it , Ram , 245's ect. I cant remember what the activity is on the CPU as is ages since i fired it up last.

I will check all of the above when i get chance , Thanks for you input everyone !

Dave.

 

[TheDaddy]

So i have got this out tonight and looked again , And how is missed this originally is beyond me But :-



Errrrrrr , So I always take a picture when I first recieve the board(s) for this exact reason. I thought maybe I had done this myself as these get moved around a fair bit and blow me its on the original pic from 2021 !!! I have no clue how i missed it , Agreed my eyes aint great these days and i didnt have my microscope then but come on ??

Fixed :-



Anyway I have fixed this and its still the same , but the pin is floating so I need to look at the pinouts if I can find them. Its the 052109 chip, It could have blown the chip. If anyone has a board and can check output of that pin it would be super !

What you all reckon ?

Dave.

 

[CMYKhazi-Dan]

What you all reckon ?

Glass of rum and Netflix

 

[TheDaddy]

Glass of rum and Netflix

Thats friday ! Lol

 

[WatchThemAllFallDown]

Nice one Dave, another one fixed 👍

 

[TheDaddy]

Nice one Dave, another one fixed 👍

No its still broke mate , Struggling with this one.

Dave.

 

[TheDaddy]

Ok so just had a look at work at schematics , The dead pin on the 052109 is pin 60 , This is FI1 and goes to Pin 13 Of the LS153 @ I 13



So this is an output from the 052109 Custom to the U13 , So basically chip is screwed as far as I can tell as pin is dead on mine. I still dont think this would stop it booting though would it ?? Unsure. I aint the best at replacing these chips as there is 120 pins.

Dave.

 

[sukhbir]

That custom chip got to be for the sprite generation ,the dead output is most likely the data bit for the ls153.
This dead o/p should not prevent the game from booting,floating,stuck high or low address and data bits to the cpu will crash the game.

 

[TheDaddy]

That custom chip got to be for the sprite generation ,the dead output is most likely the data bit for the ls153.
This dead o/p should not prevent the game from booting,floating,stuck high or low address and data bits to the cpu will crash the game.

Yeh i didnt think it would prevent booting , Going to look at the DTAC but think i have looked before and was ok. Pin 13 of the LS153 is an input so should that be generated from the custom ?? Or may it just be that the game isnt running so its not being generated ??

WHEN I get this running we will be having a party ! lol

Dave.

 

[sukhbir]

What is the HALT pin doing on the custom pcb?are there any activity on the data and address bus?
I suspect the program is not running,May possibly be a bad custom cpu.

 

[TheDaddy]

What is the HALT pin doing on the custom pcb?are there any activity on the data and address bus?
I suspect the program is not running,May possibly be a bad custom cpu.

I get some activity but need to re look as been ages since I actually went round with logic probe or scope.

Dave.