Famicom World

Family Computer => Technical & Repair Assistance => Topic started by: aha2940 on February 10, 2013, 08:31:19 am

Title: NES blue screen
Post by: aha2940 on February 10, 2013, 08:31:19 am
Hi!

I got an untested NES board, along with a 72 pin connector and the loading cartridge mechanism. I have no case/power board/controller board for the NES, only these parts (and the RF shields). I tried the board, connected it to my TV using an NES RF box, and my famicom AC adapter (10V, 850mA). I tested the board but all I get is a solid blue screen (blue as the sky in Super Mario Brothers). If I remove the cartridge, I get the same blue screen but flashing. I don't know what the LED does, since I don't have one to test. I've read that most of the time this is due to bad 72 pin connector and replacing it solves the problem. I've also read that this can be caused by a bad PPU/CPU.

My questions are:

1. Is there any way to know if the PPU/CPU are bad? unfortunately I don't have a soldering iron, or oscilloscope.
2. Is this worth trying to get fixed? or is better to just to get a whole NES?

Thanks!!
Title: Re: NES blue screen
Post by: wholesalewatch648 on February 10, 2013, 09:00:27 am
having dealt with numerous NES over the years, I have found that 99.9% of the time, replacing the 72 pin connector with a new one (found on eBay / amazon) will make the console work normally.

Here is a URL to one: http://www.ebay.com/itm/NEW-NES-NINTENDO-72-PIN-CONNECTOR-1-YEAR-GUARANTEED-NEW-/370416522396?pt=Video_Games_Accessories&hash=item563e8b949c
Title: Re: NES blue screen
Post by: aha2940 on February 10, 2013, 09:18:54 am
Thanks for the suggestion, so you don't think the CPU/PPU have problems?

Update:

I fiddled with the NES 72-pin connector and got it to produce these images:

(http://gapf.ninth.su/images/castlevania.jpg)
(http://gapf.ninth.su/images/metroid.jpg)
(http://gapf.ninth.su/images/smb.jpg)

As you can see, they are distorted, but somehow resemble the game. Are these proof that the CPU/PPU are broken? or can these be produced simply by a damaged 72-pin connector?

Any guidance/help is appreciated.

Thanks!!
Title: Re: NES blue screen
Post by: P on February 11, 2013, 02:56:09 am
I got similar images without a broken PPU. Cleaning and removing oxidation from the pins probably helps.
Title: Re: NES blue screen
Post by: wholesalewatch648 on February 11, 2013, 09:08:47 pm
believe it or not, those images can be caused by a damaged 72 pin connector.  it is pretty uncommon for the NES CPU/PPU to be damaged, im not saying its impossible but chances are most likely the 72 needs replacing.
Title: Re: NES blue screen
Post by: P on February 12, 2013, 06:31:38 am
Yes it's probably either the 72 pin edge connector or the pins on the cartridge itself. Try cleaning them both thoroughly before replacing the 72 pin connector.
Title: Re: NES blue screen
Post by: aha2940 on February 12, 2013, 01:18:54 pm
Thanks for the advices. I do not think the cartridges are dirty, because they work fine on my famiclone. Most likely the 72-pin connector is dirty/bent/rusted, but I've tried cleaning it and it's really hard to clean the back pins (they can't even be seen). Any advices on how to clean this thing properly?

Thanks!!
Title: Re: NES blue screen
Post by: P on February 13, 2013, 03:02:26 am
It's a front loader right? I have no idea about those. You'll have to google it.
Title: Re: NES blue screen
Post by: 2A03 on February 13, 2013, 03:41:02 pm
Quote from: aha2940 on February 12, 2013, 01:18:54 pm
Thanks for the advices. I do not think the cartridges are dirty, because they work fine on my famiclone. Most likely the 72-pin connector is dirty/bent/rusted, but I've tried cleaning it and it's really hard to clean the back pins (they can't even be seen). Any advices on how to clean this thing properly?

Thanks!!

Boil it in soapy water. Not kidding, I've tried this several times and it works wonders. Failing that you could also try bending the pins as most people do.
Title: Re: NES blue screen
Post by: wholesalewatch648 on February 13, 2013, 04:08:50 pm
ohhh i was under the impression this whole time we were talking about a frontloader NES not a toploader NES. I have no idea how to remove / clean the 72 in a frontloader, because i have never actually owned one
Title: Re: NES blue screen
Post by: HokusaiXL on February 14, 2013, 01:43:41 am
Paper backed emery board.  It's a disposable fingernail file but it's thin enough to sand off the oxidation on the connectors.  That and they're dirt cheap at most drug stores / walmart / whatever.
Picture Below
xttp://www.mountainside-medical.com/product_images/r/382/emery_boards1__27235_zoom.jpg
Title: Re: NES blue screen
Post by: MarioMania on February 14, 2013, 06:49:51 am
Why do people still have a nack putting there NES's 16x9 or LCD, they look bette on CRT's
Title: Re: NES blue screen
Post by: aha2940 on February 16, 2013, 10:43:07 pm
Quote from: MarioMania on February 14, 2013, 06:49:51 am
Why do people still have a nack putting there NES's 16x9 or LCD, they look bette on CRT's

Because not everybody has the space to keep an old 21" CRT. I would like to have it, so the light gun would work, but it's not the case, therefore LED display only for me.

Regards.
Title: Re: NES blue screen
Post by: tonev on February 21, 2013, 02:07:22 pm
Quote from: aha2940 on February 16, 2013, 10:43:07 pm
Quote from: MarioMania on February 14, 2013, 06:49:51 am
Why do people still have a nack putting there NES's 16x9 or LCD, they look bette on CRT's

Because not everybody has the space to keep an old 21" CRT. I would like to have it, so the light gun would work, but it's not the case, therefore LED display only for me.

Regards.


At least switch it to 4:3 every tv has the setting ( even my old samsung crt tv has a 16:9 and 4:3 modes :D )
Title: Re: NES blue screen
Post by: aha2940 on February 22, 2013, 12:13:12 am
Quote from: tonev on February 21, 2013, 02:07:22 pm
Quote from: aha2940 on February 16, 2013, 10:43:07 pm
Quote from: MarioMania on February 14, 2013, 06:49:51 am
Why do people still have a nack putting there NES's 16x9 or LCD, they look bette on CRT's

Because not everybody has the space to keep an old 21" CRT. I would like to have it, so the light gun would work, but it's not the case, therefore LED display only for me.

Regards.


At least switch it to 4:3 every tv has the setting ( even my old samsung crt tv has a 16:9 and 4:3 modes :D )


You're absolutely right. I have the A/V input setup that way, so my famicom looks 4:3, however these photos were taken while the NES board was connected via RF onchannel 3. I do not set 4:3 on TV channels, therefore the 16:9 aspect ratio.

Regards.