Log in

View Full Version : Snes repair FAQ (work in progress)



MrKitt
08-06-2004, 01:59 AM
Snes FAQ:
Ive tried to document the snes errors and how to fix them as good as i could
(still learning about it and finding new errors and finding out how to fix em) i
take no respons for anything writtin in it its on your on damn risk. dont like it ?
well fuck you try writting a better one 6 in the morning with a hangover. yeah its
probably got like 1 billion typos or bad grammar but my main language aint english
its SWEDISH. here's the faq.

oh btw if your planning to "steal" it for a page or so please ask for permission
first ill probably dont care and say its ok but still i wanna know where it can be
found. ill update it if i find out anything more.

Wanna help out a bit ? you can do this 2 ways either send me an issue that is common and how to fix it "concreet evidence" not guesses please. or you could aid me in my quest by sending me busted up consoles (all consoles are welcome broken / working :) )

Q. why doesnt my snes power on?
A. one of the following or multipl might be the cause: the adaptor is broken, the fuse
is blown, the 7805 inside the snes is broken the switch is broken.

Q. ive changed the 7805 but my snes still doesnt poweron, when i push the power i get power for an instance as the led flashes what is the problem?
A. Behind the 7805 if you remove the Coolingplate there is a small surface mounted component named D1 replace it (not sure what it is some sort of geizerbridge?)

Q. Why does my snes fuse bust all the time?
A. Your either got a broken U12 (7805) or lack the C87 Cap
most common on snes with built in Soundcards. Value of
C87 should be about 2200 uF 50V.

Q. Why doesnt my snes work with a nes/snes ac adaptor?
A. Either the adaptor is broken or your snes lack the DB1 (sometimes marked as D1)
Geizerbridge (some snes with build in sound cards lack this component)
try replacing it with a bridge that can handle atleast 1.5A!

Q. Why is the Screen black when i try to play an import ?
A. The lockout chip causes this problem (otherwise known as U8) lift leg 4
to solve problem.

Q. What would happen if i bypass the Fuse?
A. Basicly nothing of greater importance, the fuse purpose is to avoid U12 from
killing itself and the rest of the snes when it malfunctions (if for some
strange fucked up reason it tries to drain more then the max current it
can handle) this is often not a problem since U12 doesnt let power pass
once its fried.

Q. I can hear sound but it sounds really really bad and cuts what the problem?
A. your amplifier is probably malfunctioning due to failure of surrounding components
check if the amplifier cap aint displaced (not soldered as it should be like
shifted 90 degress, yes a robot slacked off and fucked up) should be a cap connected
somehow with a circuit named something like LM3xx (cant remember the possition).

Q. I get screen but some or all sprites look strange how do i fix this?
A. Check U4 and U5 for solderbridges or other oddites if you cant see anything try
replacing one at a time. (U4 and U5 are the video ram used by the PPU's)

Q. The screen fades down when i use the A/V output but not when using the RF input why?
A. Remove the Capacitors in your RGB cable due to some issues some snes units specially pal fade down and some dont even display picture at all when you use a rgb cable with caps in it (ALL fabrical constructed cables have CAPS)

Q. How come you know so much about the snes?
A. ive seen a blue print of it or rather a badly reverse enginered blueprint.(most
things on it doesnt make sense like why 50% of all pins ar grounded without any
type of explanation of their purpose)

Q. Will my US adaptor fit a Jap unit ?
A. No! there are 3 types of plugs on the snes the US, Pal and Jap. Pal and Jap look
the same but Pal uses possitive voltage in the middle while Jap uses the outside.
the Us have the same voltages pinouts as the Jap one but a diffrent plug.

Q. Do US snes have RGB output?
A. Yes all types of Snes do have RGB output but youll need a US with that supports
RGB input in the scart connector.

Q. What type of outputs do the snes have and what is the best? and why?
A. Snes supports RF, RGB, Composit and S-vhs. RF is avaible on all snes without any
extra cables its also the worst one of them all since sound and picture is encoded
in the same cable using diffrent frequencys, Composit is like a cleaner version of
the RF its almost the same but instead of having sound sent in the same signal its
seperated on its own (RGB S-vhs and Composite all use the same sound pins), RGB
is a clean seperation of RED GREEN and BLUE signal all colors are stransmitted as a
seperat signal along side with an additional signal called SYNC this is the best
hence its more sharp colors. S-Vhs is a compressed version of RGB and like most
compression you lose quality.

Q. Some games tend to reset after i while when i use a RGB cable why?
A. This is a common issue on some games with special copy protects like yoshi's island
to solve this issue replace your original snes AC/AC adaptor with a AC/DC adaptor.
the ac/ac adaptor causes ripples and interrupt something on the screen output part
causing the copy protection to active when receiving a loopback from the rgb toggle.

omnedon
08-06-2004, 09:14 AM
That is GREAT Mr. Kitt. :eek 2:

kainemaxwell
08-06-2004, 09:23 AM
Nice job thus far!

MrKitt
08-06-2004, 09:41 AM
thanks i figgured it was time for someone to publish some sort of help for people with busted snes units.. :P would have posted stuff on nes / mastersystem stuff too but havent had so much problem with neither nes or mastersystem. @_@

and o ive already mentioned this in another post but if your Nes wont work due to "nes busters" try using a small screwdriver and pulling the utter pins down on the 72pin connector.

anagrama
08-06-2004, 12:03 PM
Hmm, I've got a couple of units that I thought I fried while trying to mod them a couple of years back. No life in the at all.
D'ya think there's any chance that it's just the U12 that's the problem?
I'll have a look tonight and see if I can get any results...

Many thanks!

MrKitt
08-06-2004, 01:22 PM
if it doesnt even light the power led its probably the U12 or fuse but if it turns on but still black screen its probably the CPU (U1) who has a bad solder somewhere.

Mr. Smashy
08-09-2004, 05:25 PM
What would my SNES repair FAQ read like? Hmm...

"Q: My SNES isn't working. What can I do?
A: Find $10 and buy a working one."

Yup. Sounds about right.

omnedon
08-09-2004, 05:30 PM
Wrong forum for that sort of talk Mr. Smashed.

If you haven't anything helpful to contibrute, don't. A day may come when you will not be able to replace old consoles so easily, and this gathered information will be even more useful than it is now.

Mr. Smashy
08-09-2004, 06:15 PM
I'm sorry. :(

No hard feelings?

omnedon
08-09-2004, 06:22 PM
Jeez.

BTW, a lot of the 'restoration' guys look at broken consoles as a mountain. You climb it cause it's there. :-P

For me, troubleshooting stuff that is easily replaced, is a great way to learn to test and do some things that are best tried first on a low value item. I learned to solder on badly busted ColecoVisions. SNES's can be a great place to start for the curious, and guidance here is handy dandy.

For those who are not in the know, Mr. Smashy and I are neighbours. LOL

Gast
08-09-2004, 07:26 PM
"Q: My SNES isn't working. What can I do?
A: Find $10 and buy a working one."Well, you can always fix a broken one you found in the trash and sell it to someone for $10

Bratwurst
08-09-2004, 07:37 PM
but my main language aint english its SWEDISH, unlike US people most countrys teach 1-2 other languages besides the native one why you ask ? well if we would be so fucking stupid and only learned our native language you US people wouldnt understand us.(HINT HINT this is a insult to uneducated us people).

Nice, cohesive documentation on many of the circuit components but how would you like it if someone corrolated Sweden's social system and its inordinately large population of lazy fucks? Just saying.

omnedon
08-09-2004, 08:08 PM
I've met more educated Americans than I can shake a stick at, and I'm Canadian.

Can't we all just get along? LOL

I used to think Mr. Kitt was abrupt, but when you take into account English is not his mother tongue, and the limitations of text, perhaps some leeway is in order.

The logic of the circuits transcends geopoloitical differences my friends.

Succumb to the beauty of the logic. :)

MrKitt
08-10-2004, 12:11 AM
the point was not mach anyone more then people who actually do get offended by it :) and about the whole "what about sweden and its lame stuff" part well last ive checked sweden always gets hacked on by us movie industry and stereotypes like sweden = blond big busty bitches so dont tell me anything about critic.

btw my native language is binary :P

omnedon
08-29-2004, 10:03 PM
SNES Repair FAQ comments only. Don't make me make it look like it never happened.

DigitalSpace
09-23-2004, 03:35 AM
That is GREAT Mr. Kitt. :eek 2:

Agreed! :)

dracula
10-05-2004, 12:07 PM
What would my SNES repair FAQ read like? Hmm...

"Q: My SNES isn't working. What can I do?
A: Find $10 and buy a working one."

Yup. Sounds about right.

other than a yard sale, where will you find a snes for ten dollars?

Psyleid
02-08-2005, 08:50 PM
What are the screwdrivers needed to open snes called... where can i get them?

MrKitt
02-09-2005, 05:08 PM
they are called security bits (not the ones that are included in the bit sets)
and you can get them from a bunch of places like www.mcmelectronics.com
liksang.com etc..

or you could make your own by using a bic pen and removing the plastic tupe and then heat up the lower part and then placing it on a bit and letting it dry / cool

rarecube
03-22-2005, 03:44 AM
"Q: My SNES isn't working. What can I do?
A: Find $10 and buy a working one."Well, you can always fix a broken one you found in the trash and sell it to someone for $10

LOL

UnInformer
07-02-2005, 10:50 PM
This is not so much a repair question....but what would be a good tool to use for getting rid of the two plastic tabs that block Japanese carts on North American systems?

MrKitt
07-03-2005, 04:35 AM
a carpentknife

phreak97
07-05-2005, 10:54 AM
Because pal snes consoles run off AC, they have a bridge rectifier in them, if you run a pal snes on dc (to avoid the resetting via rgb) you can burn out the rectifier. maybe attack the problem when you come to it, it's good to keep there incase someone plugs in AC without realizing, but if your snes stops working for some reason after running on dc, check the 4 legged black cylindrical component under the metal heat sink. you can replace it with two bits of wire, but if you do, you must NEVER plug in AC again.

to kill the tabs in the cart slot: you can use a carpenters tool of some kind like stated above, you can stick some strong long nose plyers down there and just snap them off, you can use some heavy duty wire cutters to attack them, you can use an x-acto (or whatever) knife and carve them away, you can even (not at all recommended) melt them away with a soldering iron.

MrKitt
07-05-2005, 03:34 PM
well actually its a small geizerbridge and geizerbridges are made to filter AC to DC but if you input DC on its inputs nothing happens since no Sinus voltages are corrected from negative to possitive values. Please note that this is not a design flaw (the galvanic seperation happens in the AC/AC transformer also known as Electron magnetic conductance ) its a programming flaw made by gameprogrammers witch causes games to reset the snes.

Wonder_Hamster
07-24-2005, 01:38 AM
Here's a question for you:

How come my SNES will not display video? It shows a blank screen while I hear the audio just fine. I tried with A/V cables and an RF adaptor and it did the same thing. I even made sure it displayed fine with my working SNES to make sure everything was right with my TV. You know anything I can do about this?

MrKitt
07-24-2005, 05:11 AM
its probably some sort of short on the PPU2 or its busted.

ive had this error on some sneses but i havent cracked where the error is yet.. if you have an oscillioscope you can check the rgb generatator pins on the PPU2 if you get signals there its not the ppu but probably one of the million transistors on the backside of the pcb :(