AES - no cart and green screen -

Well, as the title says, I've got an AES, that when I turn it on, without cart, I get a green screen (Palette Ram error). I've opened the AES, and have found an IC (SN74AS04N) with some green gunk in some of its pins (I've checked continuity and they failed) so I have replaced that IC, but it is still showing a green screen, so I've looking for some info on Google, and I've found some hints (check HD74LS273P - there are two of them), and Neo-G0, and some Ram ICs, but what Ram ICS exactly (I mean, there are some of them across the board ...) so, anyone got more clear hints?

Probably a bad trace in that area
BB

Aren't the HD74s just hex inverters?

Well, I've been all day checking the traces of some IC's (two CXK5864BSP-10L, two HD74LS273P, HD74LS05P and HD74HC04P) and the traces where fine, tomorrow I'll check Neo-B1 and Neo-G0, but I believe that their traces will be ok ... so, my guess ... maybe one of the 2 (or both) CXK5864BSP-10L are dead or any of the two HD74LS273P are faulty as well... I will try to replace the HD74LS273P, as they are easiier to find in a normal electronics shop ....

I don't know if this will help but this is what I do:

http://www.jamma-nation-x.com/jammax/tutorials.html?show=aestrace

Action Kamen said:

Well, I've been all day checking the traces of some IC's (two CXK5864BSP-10L, two HD74LS273P, HD74LS05P and HD74HC04P) and the traces where fine, tomorrow I'll check Neo-B1 and Neo-G0, but I believe that their traces will be ok ... so, my guess ... maybe one of the 2 (or both) CXK5864BSP-10L are dead or any of the two HD74LS273P are faulty as well... I will try to replace the HD74LS273P, as they are easiier to find in a normal electronics shop ....

Click to expand...

Are you sure you checked *all* the traces of the 5864's (that's the color RAM)? Can you post a list of the connections so I can verify if it's complete or not?

The HC04 has nothing to do with this. Bad LS273's wouldn't give a color RAM error so please don't pull them off uselessly as you did with the AS04 (BTW was the replecement chip for this actually an AS04? I ask because the AS series isn't that easy to find).

If you had a Unibios you would get a full error message as on MVS boards. That would give you more info on the problem.

Hi MKL, here is the complete list of the 2 5864's

--How to understand all this text :

(1-->) = number of the pin of the IC.
--> where it goes
[..] location of an IC

I hope it is clear
----------------------------------------------
The first :

F1 (GXK5864BSP-10L)

1--> p28 [F1] --> p1 [G1] --> p26 [F1] --> p28 [G1] --> p26 [G1] --> Vcc
2--> p2 [G1] --> p12 [F10 (HD74HC259P]
3--> p3 [G1] --> p12 [E1 (NEO-B1]]
4--> p4 [G1] --> p11 [E1]
5--> p5 [G1] --> p09 [E1]
6--> p6 [G1] --> p08 [E1]
7--> p7 [G1] --> p03 [E1]
8--> p8 [G1] --> p02 [E1]
9--> p9 [G1] --> p159 [E1]
10--> p10 [G1] --> p158 [E1]
11--> p8 [H1 (HD74LS273P)] --> p35 [J5 (NEO-G0)]
12--> p13 [H1] --> p36 [J5]
13--> p14 [H1] --> p37 [J5]
14--> GND
15--> p17 [H1] --> p38 [J5]
16--> p3 [H2] --> p53 [J5]
17--> p14 [H2] --> p54 [J5]
18--> p7 [H1] --> p55 [J5]
19--> p18 [H1] --> p56 [J5]
20--> GND
21--> p21 [G1] --> p31 [E1]
22--> GND
23--> p23 [G1] --> p32 [E1]
24--> p24 [G1] --> p29 [E1]
25--> p25 [G1] --> p28 [E1]
26--> p28 [F1] --> p1 [G1] --> p28 [F1] --> p26 [G1] --> p26 [F1] --> VCC
27--> p27 [G1] --> p41 [J5]
28--> VCC

And the second one :

G1 (GXK5864BSP-10L)

1--> p28 [G1] --> p1 [F1] --> p26 [G1] --> p28 [F1] --> p26 [F1] --> Vcc
2--> p2 [F1] --> p12 [F10 (HD74HC259P]
3--> p3 [F1] --> p12 [E1 (NEO-B1]]
4--> p4 [F1] --> p11 [E1]
5--> p5 [F1] --> p09 [E1]
6--> p6 [F1] --> p08 [E1]
7--> p7 [F1] --> p03 [E1]
8--> p8 [F1] --> p02 [E1]
9--> p9 [F1] --> p159 [E1]
10--> p10 [F1] --> p158 [E1]
11--> p4 [H2 (HD74LS273P)] --> p62 [J5 (NEO-G0)]
12--> p7 [H2] --> p63 [J5]
13--> p8 [H2] --> p64 [J5]
14--> GND
15--> p1 [J5] --> p13 [H2]
16--> p17 [H2] --> p21 [J5]
17--> p18 [H2] --> p22 [J5]
18--> p3 [H1] --> p23 [J5]
19--> p4 [H1] --> p24 [J5]
20--> GND
21--> p21 [F1] --> p31 [E1]
22--> p20 [F1] --> p1 [E1]
23--> p23 [F1] --> p32 [E1]
24--> p24 [F1] --> p29 [E1]
25--> p25 [F1] --> p28 [E1]
26--> p28 [G1] --> p1 [F1] --> p28 [F1] --> p26 [G1] --> p26 [F1] --> VCC
27--> p27 [F1] --> p41 [J5]
28--> VCC

And about a unibios, nope, I don't have one, I believe it's time to buy one .... and no, I will not put any LS273 IC's ....

Xian Xi said:

I don't know if this will help but this is what I do:

http://www.jamma-nation-x.com/jammax/tutorials.html?show=aestrace

Click to expand...

That's awesome! I didn't think of that.

I can vouch for the 'holding up to light' approach. My car amp (came w/ the car...factory piece of shit) lost all bass on the left side of the car. Took the board out, held up to light (after reading it on his site) and after a few minutes...broken trace!

That list is complete and correct. I repost it in a version that's easier on the eyes:


Anyway, if it turns out you need to replace one or both RAMs, it won't be easy to find correct replacements because they need to be the slim DIP package (300mil pitch) which is not as common as the standard 600mil DIP and actually I cannot point you to any online source where the correct type can readily be purchased (Digikey has some but they're non-stocked and you need to buy $100+ worth of chips).

ResO said:

That's awesome! I didn't think of that.

Click to expand...

You can only do that on PCBs that don't have internal ground/VCC planes like later AES boards. On early ones and MVS (and the majority of arcade boards) you can't. And you can only see where the traces don't run under components and a broken trace is often not visible with eyes but can only be detected with a multimeter.

Thanks for info, MKL, and thanks again for the version easier to the eyes ...
Well, I 've been looking for Ram replacement (ebay, google ....) but as you have said, they are hard to find, so .... what if I get those ICs from a donor parts MVS , I have an MV1A that does not work, so I can put the needed Ram in the AES ... I believe it will work ...

On the MV1A that ram is surface mount. You would need an older 1-slot or a multislot.

Channelmaniac's site has drop-in replacements, desoldered from some old board:
http://www.arcadecomponents.com/catalog/item/2251646/1691354.htm

Oh! I looked yesterday, in channelmaniac's website, and didn't found anything ... yeah, I was looking exactly for GXK5864BSP-10L ... well, time to pick a pair of 8464-10!!
Thank you a lot, MKL!