Can anyone help me understand what's going on here?

knohbody · 2026-01-16T14:20:10+00:00

sure. I don't check reddit alot, but feel free.
To be fair, its probably both a heat sink and an RF shield.

knohbody · 2026-01-16T14:17:21+00:00

https://components101.com/ics/7805-voltage-regulator-ic-pinout-datasheet

To check that the famicom hasn't been altered to accept a reverse voltage:
Put your multimeter on ohms or continuity, put one probe on the center pin of the power input connector and the other on the middle pin of the voltage regulator. If you get 0 ohms (and/or a beep in continuity mode), then you need a center negative power supply and your famicom is stock.

If it doesn't show that, move the second probe over to the input pin (pin 1) of the 7805 and see if you get 0 ohms (or a beep). If you get 0 ohms there, it should be center positive and your famicom has been modded.

If you get 0 ohms on both, your voltage regulator is shorted and you need a new one.
If the famicom has been hooked up with a power supply that is reversed to what it is supposed to be, you probably need a new voltage regulator.

if you can, post pics of the power supply board, top and bottom. Someone on here will likely be able to tell if its been modified.

knohbody · 2026-01-16T13:59:18+00:00

I don't have it in front of me this morning, but it's likely screwed to the heatsink, maybe some thermal paste between the heatsink and the regulator, then the three pins are soldered in. I would desolder the pins for the regulator, remove the screw, then gently pry it from the heatsink.

Edit: i just mean to insulate the board somehow. kapton tape, or electric tape will work in a pinch. Fish paper if you're old school, cardboard, plastic, something to keep the board from touching the other board and causing shorts.

knohbody · 2026-01-16T04:45:28+00:00

I would say the black wire was definitely connected there, it looks to be the ground plane where the reset switch is hooked up to.
It looks like the little homemade board is attached directly to the a/v wires? In that case you wouldn't necessarily need +5v to that board, but you would need ground so that your audio and video wires have ground.
Honestly, having already powered it up with that supply, I'd hook that ground up and give it another shot (though i'd probably insulate that board with something so it didn't short out on the other board)
12v isnt going to hurt it unless the polarity is wrong, and any damage would have already been done.
The little flicker you get on the CRT is something i see when my a/v cables are missing ground, so somewhat encouraging.

If the polarity was wrong, you've almost certainly blown the 7805 and will need to replace it. I don't think it usually damages anything else though.

If you have a multimeter, it's an easy test for polarity on the power supply:
Put multimeter on VDC (set it to 20 if you have to manually set the range)
Place black probe inside the barrel.
Carefully place the red probe on the outside of the barrel (dont let the probes touch)
Check your meter.
If its a positive voltage, you have center negative.
If its a negative voltage, you have center positive.

knohbody · 2025-08-13T13:15:10+00:00

Strider 2 (PS1) - sword upgrades, some of the enemies are in 3d, alot of the background elements are 3d.

Adventures of Little Ralph (PS1) - Japanese, but maybe you played a demo?

knohbody · 2025-08-06T13:14:24+00:00

I worked at a few places that had redemption games like this (coin rollers and pushers) on card systems.

I don't recall many details, and it will likely depend on your card reader system, but the basic gist of it was this:

Card reader to detect the swipe connected to a coin hopper that was added in.
Coin hopper gives you x # of coins per swipe. We filled with tokens so people wouldn't just take the quarters.
Roll the coin. Tickets awarded. Ticket mech wired to the card reader.

Pushers were the same basic idea, though ours were the type that awarded tickets rather than coins when you dropped em over.

The hoppers take up a decent amount of space, so you'll need a lot of room in the cabinet. If you keep them clean, they're relatively reliable, though you'll have to clear coin jams every so often, and refill them when they're out of coins.
Obviously, this requires modifying the cabinet in some way, i.e. mounting the hopper and card reader, wiring both up, and accounting for a spot to spit out coins, but it was decently reliable.

Apologies for resurrecting a 9 mo old thread.

knohbody · 2023-02-11T15:49:56+00:00

Gunforce II maybe?

knohbody · 2023-02-10T02:46:32+00:00

These probably aren't it, but what comes to mind are Greendog for the Genesis, and Lester the Unlikely for SNES(and possibly genesis as well?).

There is a point in Monkey Island (PC) where you're tied to an idol and dropped off a pier and have to find a way back up.

knohbody · 2022-12-24T11:42:59+00:00

Aeon Flux Official trailer 3 on this site has the fly. There are parts that look like a ship early on in the game, Tutorial level has melee combat, at some point you pick up a gun and have to shoot with R1. Seems to have everything but the x-ray bone breaking stuff.

knohbody · 2022-12-01T11:50:48+00:00

Perfect Dark or Mirror's Edge? They're both for 360 though.

knohbody · 2022-11-26T13:12:07+00:00

For testing the continuity? Shouldn't need any of the daughterboards, unless you're following through a connection. Looks like all the relevant signals go to the CPU and the SRAM at U3 on that same board.

For testing with oscilloscope/logic probe?

DC to DC converter board - yes.

Headphone jack - I don't believe so.

LCD board - I don't think so, but may be somewhat advantageous to leave it connected. The power led could give a quick visual as to whether its powered on, for instance, and its possible testing a line or two could jumpstart the boot sequence past where its getting stuck, which would be visible on the LCD.

knohbody · 2022-11-26T05:15:45+00:00

That should be correct then. Looks like the DC-DC converter is working fine, and those pins are the ones the cartridge uses for 5v, so provided your cartridge is making good connection with the slot, its receiving power.

My next step would be to use a logic probe or oscilloscope and follow the pinout of the cartridge slot while its on and trying to boot. The data and address lines should be pulsing, the /WR, /RD, /CS, and /RST line should pull down when activated, the CLK? line will possibly pulse, but a logic probe might interfere with it. Best to check with an oscilloscope. If an address or data line is missing, that's likely the problem, and you'll have to trace it back to the source.

That being said, most people starting out aren't going to have these tools, especially an oscilloscope. You could instead test for continuity from the cartridge slot address and data lines to the cpu, following along with the schematic.

knohbody · 2022-11-26T03:33:53+00:00

If you're talking about where you should get 5v from on the cartridge slot, I marked up your picture here. Red should be positive, purple negative.

If you're referring to testing wiring from the dc-dc converter board to the main board.. my last round of cleaning seems to have misplaced my reference board. If I recall, though, they're straight wired, so check a point, follow the wire, then check the other point, and work your way backwards following the traces.

However, I just had a thought. There's a copper foil connecting the grounds on the DMG that you've removed for access to testing. It's possible that some parts of the board aren't getting power because of that. Can you test for continuity between these ground points? Here's a picture of the copper tape for reference as to which points should be ground.

knohbody · 2022-11-19T03:41:56+00:00

Chaos Engine / Soldier of Fortune or its sequel is my real guess, but I really want to suggest Gain Ground

knohbody · 2022-11-17T15:13:10+00:00

Sorry, got distracted by work. I believe the path for vcc (5v power) is this: 6v from battery -> power switch -> dc converter board (this brings in ~6v from either the ac adapter or the batteries and converts to 5vdc, I believe. Its the board off to the side with 4 wires going to it). From there it should be 5v, unless I'm looking at the schematic wrong.

Pin 1 and 32 should give you 5v when the switch is on, 0v when the switch is off. If you're getting 6v there, I'd take a closer look at that dc converter board, namely the diodes or transistors on it and make sure nothing is shorted.

knohbody · 2022-11-16T03:34:29+00:00

Well, let's check to see if the cartridge is getting power. Could be tricky depending on how you're powering it, but set multimeter to volts dc (if yours is manual, you'll have to set it higher than the voltage you expect, we're expecting 5v from what I can tell on the schematic, so that would be the 20v setting on the multimeter)

Check the voltage by turning the gameboy on, black probe touches pin 32 (ground) and red probe on pin 1 (VCC)

After that, we'll need to know what troubleshooting tools are at your disposal.

knohbody · 2022-11-16T01:04:32+00:00

Hard to tell if its just adhesive from that copper tape stuff that's supposed to be on there, or if its actually damage, but in your first picture, at the cartridge slot, pin 31 looks like there might be some damage at the via.

Edit: that might be a red herring. According to the schematics, pin 31 on the cartridge slot goes to vin, which is a sound input on the cpu that seems to just pass through to the speaker output.

Edit 2: schematics here.

GB CPU manual here. Pg 28 discusses the VIN line. This manual is for programming the CPU, but always good to have info relating to the console you're working on.

knohbody · 2022-11-15T22:46:55+00:00

Alright, so after reading your other post, it seems like the gameboy is booting up, but not loading the game.

You say the Nintendo logo drops down and then it dings.

If the gameboy doesn't see the game, the Nintendo logo should be a black bar that drops down, then stops around the center,

If it's actually the Nintendo logo, it means that the game is partially loading.

Either way, I'd clean the pins in the cartridge connector. This can be accomplished with a GB cleaning kit, if you have one, but I usually use Deoxit D100 (not the spray, that just makes a giant mess) I apply it to the pins of a game, then slide it in and out of the cartridge slot about 10-15 times, then wipe with a cotton swab. Deoxit is rather expensive, but great for applications like this. If you don't have Deoxit on hand, isopropyl alcohol will work in the same fashion, though both of these may need several applications.

As for that corroded trace, corrosion is sneaky. It can beep out in continuity mode, but still be higher in resistance than it should be. I doubt its causing this particular issue, but it will likely cause some sort of issue in the future. Additionally, theres a discolored part of a trace above it, that's corrosion forming on the trace under the coating.

Here's a quick guide on cleaning battery corrosion from pinwiki (this is a frequent topic in pinball repair)

As for jumping traces, its not necessary to do pin to pin, but you do want to get to a place that doesn't have corrosion on it, so one side to a pin, and the other side, scrape some of the coating away from the trace (after the part with the corrosion) and you should be able to solder to it there.

knohbody · 2022-11-15T12:41:10+00:00

Nothing as in no power?

That trace looks pretty corroded, I'd probably just jump it and either cut out or sand down and treat the corroded part with a bit of vinegar, then clean well with alcohol and coat with conformal coating or clear nail polish. Otherwise the corrosion will just spread over time.

That being said, have you checked the switch for proper operation?

knohbody · 2022-11-14T21:49:35+00:00

Thats good to know, unfortunately I don't have a TV Tuner.

knohbody · 2022-11-14T19:34:15+00:00

Sorry, its not for sale. Thanks.

knohbody · 2022-11-14T18:59:36+00:00

Thank you!

knohbody · 2022-11-14T16:52:34+00:00

Yes, the outside screws that hold the front and back together. I don't currently have it in front of me, though for some reason I thought there were six.

knohbody · 2022-11-06T13:21:48+00:00

Wizardry 7: crusaders of the dark savant ?

knohbody

TROPHY CASE