Famicom World

Family Computer => Technical & Repair Assistance => Topic started by: fahlim003 on June 02, 2013, 09:05:24 am

Title: Famicom - Grey screen
Post by: fahlim003 on June 02, 2013, 09:05:24 am
I picked up a Famicom (HC1413422) with HVC-002 ac adapter today in a lot with other electronics. It came with 1 game, Goonies 2 but is missing the original RF adapter. It's fairly clean, although without cleaning Goonies 2 (which incidently was inserted when I received it) I powered it on. I used an NES RF adapter which I assume wouldn't be a problem. All the same, I get nothing but a grey, sometimes a different coloured, screen upon power on. Once I hit reset and got a garbled Goonies 2 title screen but nothing since. The cartridge was quite dirty and I cleaned it fairly well with Windex and a cotton swab but to no avail. I assume the issue might be the cartridge connector but I've come up with very little information on Famicom problems, so here I am. Any help is appreciated.
Title: Re: Famicom - Grey screen
Post by: Lolmann on June 02, 2013, 09:37:50 am
Sounds like either the cartridge or the connectors have gone to shit. Have you tried any other cartridge?
Title: Re: Famicom - Grey screen
Post by: fahlim003 on June 02, 2013, 09:48:28 am
Quote from: Lolmann on June 02, 2013, 09:37:50 am
Sounds like either the cartridge or the connectors have gone to shit. Have you tried any other cartridge?
Unfortunately, I only have the one game which somewhat limits testing. I used to have Moai-Kun and Argus but that's many years ago.

Post Merge: June 03, 2013, 11:18:37 am

Opened the system up today, it's an HVC-CPU-GPM-02 motherboard.
I also cleaned Goonies 2 with WD-40 and took a lot more dirt off, likely from the cartridge slot. The game loaded up to the title screen but did not accept input. When reset went to some garbled screens, eventually to grey (with pink and blue) screens. Since it's so inconsistent in loading actual graphics I don't know if the Video SRAM is failing or perhaps something else. Given that the title screen has loaded and without errors I don't think it's that at this point.
Title: Re: Famicom - Grey screen
Post by: P on June 03, 2013, 12:23:19 pm
I wouldn't clean it with anything else than 99% isopropyl alcohol. Anything else may speed up corrosion on the pins.

I suggest to clean it again with but with 99% isopropyl alcohol and wait at least an hour so you are sure it's dry before testing again. See if it get better at all.
Title: Re: Famicom - Grey screen
Post by: L___E___T on June 08, 2013, 02:16:11 am
I get this sometimes and have to be honest I just blow the pins.  Is that really damaging over time?  How much so?
Title: Re: Famicom - Grey screen
Post by: P on June 08, 2013, 11:41:44 am
Maybe it speeds up oxidation of the pins because of moist in your breath. I'm not sure it makes a very big difference though, but I don't think it really helps either if there isn't visible dust or other trash in there. It may feel like it helps because when you insert the cartridge again after blowing on it you may be lucky and it makes a better connection than the first time.

Oxidation is the biggest problem and removing it makes the game work flawlessly even if you wiggle it. It's not fun when you have come far in a game and then it suddenly hangs with garbled graphics because you happened to bump the Famicom slightly. After removing oxidation from my FDS Ram Adapter and some trouble cartridges, with a fiberglass pen, I never had that problem again.
Title: Re: Famicom - Grey screen
Post by: fahlim003 on August 23, 2013, 04:40:22 pm
So I had the system cartridge slot cleaned by a friend today and afterward I cleaned Goonies 2 again with isopropyl alcohol several times. Initially, Goonies 2 booted up and worked then froze shortly into the game. I cleaned the cartridge several more times and got varying degrees of booting, whether the start-up screen for Goonies 2 would move slightly before freezing or nothing at all. Any ideas or is this system toast? Again, I wish I had access to another game to test but perhaps that's unnecessary.
Title: Re: Famicom - Grey screen
Post by: XiTaU on August 24, 2013, 05:15:58 am
i always used to use an eraser like that on my neo geo carts and it worked a treat fixed every non working cart i ever bought.
Title: Re: Famicom - Grey screen
Post by: ebinsugewa on September 14, 2013, 12:01:58 pm
Eraser or reaaaally fine grit sandpaper should do the job.
Title: Re: Famicom - Grey screen
Post by: fahlim003 on November 07, 2013, 10:58:15 am
Today I had the soldering iron out and decided to reflow the joints of the cartridge slot.

Like before, it booted on first try and was playable. I reset and the problems began again. The screen didn't change colours, just grey but the system progressively had more trouble functioning every time I powered on/inserted the game cartridge. It seemed issues would also arise if the 2nd player controller was touched or even if input was made on 1st player. It's annoying but I think I'm done fiddling with this system unless someone can provide a concrete answer why these issues are arising.
Title: Re: Famicom - Grey screen
Post by: Gamer83 on November 22, 2013, 08:34:18 am
I had similar problems with a famicom I'm currently working on.my problem had to do with poor /broken connections at the ribbon cable that connects the power supply and rf board to the main board.very similar problems,none of my games were working, I'd get the grey screen garbled graphics and sometimes a random colored screen. noticed when I moved the rf/power board around outsidethe case, sometimes the game would boot.so what I did was, removed the ribbon cable,cut off both ends that were soldered, stripped a fresh 2 mm of wire, use a multimeter to check the continuity of each wire.once that tested good, I resoldered the ribbon to the two boards, and bam worked perfectly. this might not be your problem but its worth a try.other things I'd recommend checking are, the pin placement in the cart connector, might need to adjust those.also check 7805 voltage regulator, fuses and capacitors on the psu. hope this will help.
Title: Re: Famicom - Grey screen
Post by: aha2940 on November 23, 2013, 05:15:54 pm
If you have some experience soldering, you can try to do an AV mod on the famicom and try to rule out that it's somehow a problem with the RF module. Do not forget to lift the pin 21 on the PPU when doing the mod (it will disable RF but it's totally worth it). Also, check the output of the 7805 transistor, it should give 5V (more or less, 4.9 or 5.1 is OK usually). Maybe it has some overheating problems, since it seems it plays fine at first, but after some time (when it heats up) it gets messed.

Hope this helps.
Title: Re: Famicom - Grey screen
Post by: Pemdawg on March 01, 2014, 09:33:47 am
Into am getting a Grey screen error. Booted up last night and was fine but now nothing will run, no matter how much cleaning I do to the contacts! My system has a replacement RF section, and brand new capacitors throughout, so count those out as possible issues.
Title: Re: Famicom - Grey screen
Post by: number47 on December 28, 2014, 01:04:11 am
OK, my turn.
Got yesterday one Famicom dissected on my table with the same problem. Cleaned the slot with alcohol and reflowd the cartridge connector.
Tapped directly to pin 21 to get video to my monitor and picture is gray in the beginning. When hitting reset the color varies: blue, purple, white, gray.
There is no sound also - not at pin 1, pin 2 or mixed in the cartridge slot.

I dont't have any spare cartridge slots at the moment. Maybe I'll try hardcore soldering one crappy cart directly to the system tonight.

Any suggestions?
Title: Re: Famicom - Grey screen
Post by: 80sFREAK on December 28, 2014, 03:56:02 am
Quote from: number47 on December 28, 2014, 01:04:11 am
OK, my turn.
Got yesterday one Famicom dissected on my table with the same problem. Cleaned the slot with alcohol and reflowd the cartridge connector.
Tapped directly to pin 21 to get video to my monitor and picture is gray in the beginning. When hitting reset the color varies: blue, purple, white, gray.
There is no sound also - not at pin 1, pin 2 or mixed in the cartridge slot.

I dont't have any spare cartridge slots at the moment. Maybe I'll try hardcore soldering one crappy cart directly to the system tonight.

Any suggestions?

Clean the cart, reflow trimmer around crystal and "shake" it by turning half turn both sides. Be sure to leave trimmer as it was before.
Title: Re: Famicom - Grey screen
Post by: number47 on December 28, 2014, 04:30:14 am
Is the problem related to corrosion and short in trimmer? In my opinion the wrong position of trimmer cap should mess up only colors not the whole picture.
Title: Re: Famicom - Grey screen
Post by: 80sFREAK on December 28, 2014, 07:18:55 am
Some sort of oxydation. Lots of communication equipment made in late70-late80 suffer from these trimmers failure.
Title: Re: Famicom - Grey screen
Post by: number47 on December 28, 2014, 01:06:05 pm
Ok. Shaken - not stirred but still the same. Still seems like cart connection error because it doesn't matter if the cartridge is in or not. Tomorrow I'm going to try with replacement slot.
Title: Re: Famicom - Grey screen
Post by: 80sFREAK on December 28, 2014, 10:49:36 pm
First try 600grit sandpaper.
Title: Re: Famicom - Grey screen
Post by: number47 on December 29, 2014, 09:18:57 am
Now the situation is even worse. No signal at all. I must have shorted something  :(
PPU is not warmer than before, but CPU gets hot quickly.
Title: Re: Famicom - Grey screen
Post by: maxellnormalbias on December 31, 2014, 12:22:24 pm
Unless you want to replace the CPU and game card slot, I think it's better to just get another Famicom.
Title: Re: Famicom - Grey screen
Post by: number47 on December 31, 2014, 11:15:27 pm
Cartridge slot replacement is nothing special - been there, done that. CPUs and the next Famicom are still travelling somewhere between Asia and Europe  ;D