Chiller NES Motherboard issue

[Endgame22]

Hey guys n' gals, I recently found myself a copy of Chiller for NES. I tried cleaning it and testing it on different systems but it doesn't work properly. It screams at me (which is normal) but it is a white screen. I press start and I can hear sound and see the monsters but the monsters are all solid gray and the environments are missing. I opened up the cart and judging by a picture I found online, I think this board is missing a resistor.



As you can see in the picture of my board, there are 3 resistors at the top left, but in this picture I found online, there should be 4 there.



I am hoping this is the issue and that it can be solved. I could probably replace the resistor but I can't tell which one I need. Does anyone else have a copy that they can take a look at the board and check?

Thanks.

[Ed Oscuro]

I'm not a hardware expert, but it does sound like the graphics (CHR) ROM isn't being accessed.

http://bootgod.dyndns.org:7777/profile.php?id=1159

First thing to ask is whether it looks like there ever was a resistor soldered there. If not, I'd look at other things.

It's unlicensed so I wonder if tricking / shocking the lockout chip has any relevance...I'd look at U2 (CHR ROM) and U3, a 74LS377N which would be cheap to replace if it's gone bad. Also the traces and solder joints for any signs of breaks or wobbly stuff.

Oh, and I'm sure you know, but do be careful not to zap the board elements with static electricity, if that's your image; PCBs should normally be held at the edges only. On the other hand, if there's bad solder connections, sometimes lightly pressing on these elements can fix / change behavior temporarily. Good luck rescuing a real classic!

[Endgame22]

The top picture is mine. I'll hold it from the edges from now on then, good to know!
The top left where the resistors are it does look like something was soldered there, you can even see a little bit of solder on those two points on the left.

[Ed Oscuro]

Oh duhhh, I linked the wrong thing earlier.

This looks more like it:
http://www.nesworld.com/fakechiller.php

Do these images look like the back side of your PCB, marked Color Dreams or AGCI? The earlier PCB shot I linked, with the little bit sticking out at the top, seems to be common. It might be the original and this is a boot, or just an alternate.

Sounds like your guess might be accurate. I'm wondering why you didn't find the resistor in the case...does the game or the case shell look tampered with? It's not really critical, but would be nice to know.

Replacing the transistor shouldn't hurt anything, but it would be good to get the right value the first time, and I can't see the transistor in your comparison pic well enough since it's so small. Searching for NES Chiller PCB or even "Color Dreams" PCB images didn't bring up better photos, other than that NES World shot which just shows the back of what might be the same PCB.

If you do lock in that it's a Color Dreams / AGCI PCB, here are some places you could try asking:
NES World (the author of that article above should still have the game, I'd hope)
Infinite NES Lives (they manufacture new PCBs and mappers for the NES)
Nintendo Age
NESdev Forums

[Endgame22]

I don't see or feel anything loose or cracked on the board.

Mine is the Color Dreams PCB, the game looks like it is in it's original casing. Here is a picture I took yesterday (excuse large size).

http://i.imgur.com/L81seWF.jpg

The back where the warning label is placed may have been opened up previously. The sticker is supposed to cover the middle screw but the middle screw is visible on mine, the sticker has been pushed through on that spot. I don't think it's bootlegged, didn't AGCI release the game through Color Dreams at first? All the matching chips are there that I've seen online, it's just that one resistor that seems to be missing.
Here is a better picture I found on that website link you sent me of the front of the Color Dreams PCB, hopefully better to tell what resistor I need (if you flip my image upside down to compare).



*EDIT I notice the CHILPRG chip on mine says 9020MAD as opposed to 9020MAA which the picture above says. Not sure what that means.

[Ed Oscuro]

Thanks for that. Unfortunately I still can't make it out. Looking carefully at the first picture again, it does look like the larger PCB design also has the same eight resistors on it (one is hiding under the blue capacitor). Finding a picture of that is proving difficult, too, but at least it opens up your options a bit.

I'm probably just not familiar enough with resistors and an old hand would immediately be able to tell you what you need. Unfortunately, in the first pic with the resistor spot populated, it looks like there's two red bands and maybe a silver; in the latest one, it looks rather different.

At worst, you could just try experimenting.

As for the PRG chips, it kinda sounds like you have a revision. Woohoo! Don't think that's a date code. More reason to go ask some NES experts about this one.

[Endgame22]

I tried looking up the color band values for the resistors, I found a calculator for them but I when I compared the resistors on the bigger PCB to the Color Dreams one I have the Ohms values were different for some of them. I have no idea which resistor I need for my PCB, I am not sure if there is a way to measure the amount I need to add.

Thanks for your help Ed, this has helped a bit. I'll reach other forums about this as well but if anyone on here has any answers then please let me know.