the official Channel F thread!

[e5frog]

If it's the first version:
Remove all the small screws along the edge of the shielding (you may have 

Unhook and pull out the RF cable

Remove the metal cover over the cartridge holder (if any).
Unscrew the cartridge holder
Unplug power connector

Carefully pull the cartridge flat cables out of the connectors

Unplug power connector from the inside of the shielding to be able to remove top of the shielding

Unhook controller connectors
The you need to unsolder the grounding braids
You may have another screw in the upper left corner holding the PCB down
Unscrew the heatsink for the 5V regulator to be able to lift the PCB out

I think that's it

Easy peasy.  

The Channel F II is easier but you have to break loose the eject button to be able to remove top shell of shield.

[Yosikuma]

Mine is a System II. Break the eject button?? Like snap it off??

[e5frog]

It's attached with two raised section, they are glued. You need to bend them loose.

[e5frog]

Like so.

[Yosikuma]

Man, I am getting an education. I'll see what I can do once I get home! Thank you for the help so far. Here's hoping I can make something good happen.

[Yosikuma]

Well got inside. Don't see anything blatantly wrong.  Checked to see if any of the chips are loose. Admittedly I am hesitant to use much force on the chips as I don't want to destroy them but they seem to refuse to budge.

[e5frog]

There's five 40 pin chip, as you can see the pins a very blackened, oxidation may cause bad connection between the chip pin and the socket. 
If you can't/won't/don't dare I recommend asking someone who do/can/dare or sell it. 

The graphic error could be the RAM chips (four small ones in sockets). 

Since it's freezed it seems the CPU or PSU:s are to blame, it's just stuck and graphics from the ram is simply displayed on the TV without updates. 

But it's advisable to do the free options first.
Power it up, check if the red LED by the two metal towers light up. You can also measure the 12V and 5V with a multimeter on the capacitors by the 3850 chip (it's the CPU).
Also push on top of the visible socketed chips, there's more under the cartridge holder but leave them alone for now.

 

12V is on the capacitor pin closest to the controller ports and closest to the metal box. 5V on the other capacitor in the same spot. You may note the negative side is connected to the large grounded surface. Negative probe can be held against the metal cage or anywhere on the large metal area on the board - or the other leg of the capacitor if you want to. 
Be careful not to make a connection between capacitor pin and the ground area under it. 

 

Then with RF hooked up to TV with the nice mosaic patter... press reset, wait 3 seconds, press 1 for hockey, wait 3 seconds, press 4 to start, wait 3 seconds, if you can't hear any sound when volume is turned up on the TV with pattern visible - press 4 again and wait a few seconds. If there's sound... swap all RAM chips.
Again, check if the LED by the two towers (trimmer coil shield metal boxes) is turned on, if it is then shut off and proceed. 

It's a lot easier if you remove the motherboard from the metal box, I suggest moving operations to your metal kitchen sink for ESD safety.
You need to unscrew the cartridge holder and pull the flat cable from the motherboard connectors (which will be cumbersome to reattach). 
Now you'll also see the two Program Storage Units that hold the built-in games.

 

Pull the white ribbon cable by the two regulators. 

The two regulators are sometimes screwed to the metal, can't decide in this case. 

Someone has added screws on the two joystick-ports, they need to be removed - basically any screw you can see needs to be removed. 

 

Regulators are usually socketed (could also be a source of bad contact because of oxidation) , you should be able to remove those - NOTE WHICH ONE IS WHERE! 7812 and 7805 with or without letters added or other numbers as well.

 

Finally it's the ground braid that needs to be parted from the metal box, if you don't have a solder iron you can use pliers/scissors/toe nail clippers/teeth and cut it in half and you can connect ends with one of those cable joiners with screws. Or as close to the soldering spot on the metal box as possible so it can be reattached with a soldering iron if needed. 



Pull board out by getting a grip on the opposite side of the controller ports/regulators/RF-connector, you need an angle to pull the ports and RF connector out out of the metal box. 

Note the direction of the chips, a photo will be enough. 
It's now easier to put a flat head screwdriver (or equally flat object) between the chip and socket and twist the screwdriver slowly.
MAKE SURE it's not between the motherboard and socket - you'll damage stuff. 
Lift a little on one side with this twist method and then on the other side, a bit at the time as the legs will bend if you violently tear loose one side all the way up.
It's often enough to simply pry out chip half way and push it back down a few times to wear off oxidation.

Start practicing on the small RAM-chips, it's not that difficult. 

 

I like to remove one chip at the time and make sure it has metal gloss on pins. You can hold it under water (protects against ESD) and scrub it along the legs from top to bottom with steel wool/scotch brite/brass metal brush/melamine sponge until you have shiny legs again.

If you have a solder iron you can tin the legs and remove excess with desolder braid - it adds oxidation protection but it's slower. Dry and blow the chip, make sure there's no water left that can short it. You can blow it with a hair dryer if you want to be extra careful - but if it's not visible, it's not going to be a problem.

With all chips done (and in the proper direction, compare to your photo), preferably put the board back in the case, make sure the ground braid doesn't touch anything, reattach the white flat cable for power and populate the RF-connector, no need to reattach the cartridge holder yet. 
Now for a test... was it oxidation or something worse...  turn it on... any difference?
 

If it's a bit more than you want to handle you can print this, and a copy of the schematic and see if you can find someone with a solder iron (they likely have some experience). 
Next step would be to check chip functionality - it's easiest if you have another, working, unit to test your chips in.

 

Schematics: 
http://channelf.se/veswiki/index.php?title=Schematics
 

I have the reverse engineered schematic for the Channel F II as well but I only have Luxor and SABA versions of the second generation - which are the same apart from video output, that obviously work anyway so it's not interesting. 

If you want to pay shipping back and forth to Sweden (motherboard would be enough) I'm very likely to be able to send back a working board unless it's the custom 40pin chip FCMxxxx, not sure I have working versions of those - they need to be pulled from another board. Not really available on the free market. 
It might be cheaper than finding a commercial electronics repair-guy that might be helped by this information and the schematic. 

The UK Grandstand boards usually have all chips soldered but the 3850 CPU, they rarely suffer from these sort of problems. 
If you can make sure chips are working you could desolder sockets and solder the chips directly on the board to better future proof the functionality. 
Swapping the two 5V/12V capacitors could also be a good idea if soldering work is done to it. 

[Yosikuma]

Your offer to ship to Sweden and back sounds great except it looks like the chips are indeed the FCM custom chips, just as I feared. If those need to be replaced, I have no clue where I would source them. As opposed to when I needed a new TIA for my Atari 2600, I can’t just buy these chips online, clearly. 

[e5frog]

I meant, if they are broken it's difficult to source new ones, most other things I can replace. 
Atari 2600 was a bit more common, the TIA:s might have been used in other things as well... actually have a couple of those myself.

[Yosikuma]

Well I still may take you up on this. I am talking to a local guy here first to see if he has any ideas but he wasn't even aware the system existed until I told him, so I am not terribly hopeful.

[+atari2600land]

I am having horrible trouble trying to find a box the right size for Trimerous. I am wondering if people are okay with a bubbleope.

[e5frog]

Hey Chris! Nice to see you're still with us (not a Covid-19 victim).

 

Possibly, they're pretty sturdy with the cart inside, if box is cut and assembled. 
If you make fold/s on the uncut box along the pre-creases it might be easier to find a working size, perhaps one of those cardboard envelopes or book mailers in a large enough size. Wrapping the box print in bubble wrap will undeniably end with the box bent, maybe damaged. 

https://www.amazon.co.uk/292mm-Cardboard-Envelopes-Mailers-50/dp/B00HVXYWN0

 

There are companies you can leave goods to and an address list and they'll pack and ship it for you, might not be economically sane for such a small amount. Then it's on their warrant though and they'll pack well (and charge well).  

 

Perhaps someone in the US can help out, cut and fold all boxes. There are people with home X-Y cutting machines that could solve that part rather easily.
 

... I'm having trouble lately to get any box prints at all. Maybe I could ship Tetris in inside-out wrong creased Trimerous boxes (if I haven't dumped them in the recycle bin already) that I write Tetris on with a marker.     
Seems I'll loose money in that end anyway as nobody has ordered one or shown interest since I let ordering loose. Might as well take that loss later one.   (it's a joke, I'm bothering the printers every week, no replies).

 

 

Edited November 4, 2020 by e5frog

[+atari2600land]

I guess I'll keep looking for a good enough box.

[+stupus]

Wont they fit good in the small size usps boxes? Those are free too.

[+atari2600land]

The box won't fit very well. I think I've come to the realization that I'll have to put the boxes in a folder and mail them out separately. I went to an Office Depot store and their box varieties were lacking. You know those boxes shirts come in? If only I could get some like that. That would be perfect.

[+stupus]

You mean with the game box still flat it wont fit in the usps small flat rate box?

Man i have tone of boxes....i would be willing to send you enough but i dont know if thats a feasible thing to do?

What size do you need ideally? A larger than needed box usually doesnt change the cost if it stays under 12". Your mostly paying for the weight.

Sean kelly has a neat way of sending his vectrex games with the box flat and game cart in 1 end.

He uses a flat cardboard mailer but makes an extra fold on one end for the cart. So i end is like 1" and the other end flat. Hard to explain i guess but you can make it from a flat piece of cardboard even.

 

[+atari2600land]

Well, I'll go to the post office Friday and see what they have.

[+stupus]

This is the size of the free small one:

 

Small Flat Rate Box

USPS-Produced Box: 8-5/8" x 5-3/8" x 1-5/8"

[e5frog]

You get it down to 11x19.7 mm with two simple folds.

(4.33" x 7.76 " for the infidels)
Which means stupus recommends a box that fits.

 

 

Tada!
As I have understood it, boxes are shipped uncut?

I promise I'll deliver boxes ready to go next time - for two carts payment... I didn't know it was going to be difficult to do this. I have for ten years or so and now and then I've had a blister on the thumb from the scissors - which I have bought new and sharp two times during this time. Like a hot knife through butter.

[e5frog]

Cartridge is 20mm thick, 0.79" - so it should fit in that box as well with box folded twice.

[carlsson]

Now look at them yo-yo's that's the way you do it
You play the homebrews on the Channel F

That ain't workin' that's the way you do it
Money for nothin' and chicks for free (*)
Now that ain't workin' that's the way you do it
Lemme tell ya them guys ain't dumb
Maybe get a blister on your little finger
Maybe get a blister on your thumb

 

(*) Ok, I know this line should rhyme with F but the only words I could come up with were Jeff, chef and clef and I don't know who Jeff is in this context and why you should bring him chicks.

Edited November 5, 2020 by carlsson

[e5frog]

Carlsson... har du tullat på glöggen redan? 

{... have you already started on the spiced warm wine (which is a traditional Swedish Christmas beverage to enjoy in small amounts with almonds, raisins and whatever people put in there - preferably with gingerbreads)}

Should make it into a karaoke cartridge with music, the Sleisza music routine has a few cycles where it might be possible to put some graphics out, probably with a staccato effect.

[+atari2600land]

I found a box that fits. Oddly, the post office had 24 of them. Expect them to be on sale later today.

[+atari2600land]

On sale now! Get 'em while they last! (Trimerous cartridges, that is.)

[Yosikuma]

Okay, another System II question: got my hands on a functioning System II unit -- mostly.  There is something wrong with how it outputs a signal.  When you turn the system on or change to channel 3, the image is very briefly visible, and then the signal is lost.  Any ideas?