HunterZero

So you removed the AY-3-8914 sound chip, and put an NTSC AY-3-8900-1 STIC where the sound chip was? In some Intellivisions the AY-3-8914 sound chip is soldered in, in others it's socketed. When reversing the changes, did you socket the sound chip? The symptoms you are reporting definitely indicate a bad sound chip unfortunately, but double check any soldering work that you did. You need to be very conservative with heat and be careful of static discharge when working with ICs. This mod ONLY requires soldering to replace the 4.00MHz crystal. What model Intellivision? Do you have a pic of your logic board?

Yes, the oscilloscope will show you if the volts are held at 5V or 0V, or pulsing between. A digital 'scope with a memory can 'pause' the waveforms so you can read the data on the lines. - J

A logic probe connects to 5V and ground reference points, and you can then probe chip data legs/lines in 5V logic circuits for activity. The pen will then tell you if that line is held high, low or pulsing. An oscilloscope can do the same thing, but can display the pulses on the data line.

You should be using 60/40 tin-lead solder (it's easiest to work with), and a soldering iron suitable for electronics work. Ideally a temperature controlled one, so you can boost the heat when needed. If you have a temp controlled station, I find around 300-310 degrees C works for most general work, boosting the temp up a bit for ground planes. When desoldering: 1. Tin the tip of your iron (melt some solder on it and wipe on the wet sponge pad or use a wire wool cleaner), the tip should be bright silver 2. Optionally add flux to the joint (you can buy flux pens cheaply at the electronics store, it will last you ages) 3. Heat the joint with your iron and add new solder to the joint to help the old solder melt and flow 4. Use a desoldering pump or braid to wick away the old solder 5. Clean the pad using isopropyl alcohol and cotton tip For a good solder joint... 1. Optionally apply some liquid flux to the pad being soldered 2. Heat the joint with the tinned soldering iron for a few seconds FIRST, then apply solder to the joint (NOT the iron!). The solder may not form a nice cone initially, keep the heat on it and it should flow into the correct shape and stick when it reaches the right temperature. The solder should flow easily into the joint when it's hot enough, almost instantly in most cases. If the solder doesn't appear to stick after several seconds of direct heat, either your iron isn't hot enough (check if you are soldering a ground plane connection), or the surface being soldered is not clean enough. 3. Clean away any leftover flux with isopropyl alcohol The pads on the regulators are not very large, so be careful not to feed too much solder in. If you do, you can always wick or suck some solder away and retry. Be careful not to lift the pads. If the pads lift it's not the end of the world, you can work around it. Note pads that are connected to large trace areas eg ground planes can require more heat. If the solder is not sticking, then either the pads are dirty, or you didn't use enough flux, or you used not enough heat. Ripping the ribbon cable - Ugh, not ideal, these are so fragile and fall apart so easily. Try taping it to keep it together but check continuity is good. Someone on here did have some new old stock ribbon cables, but you can replace the 5 pin connectors with 2.54mm 5 pin connectors and some ribbon wire. Eg:

Indeed it looks like an address line between the STIC and GROM is stuck high (0x00 background card is displaying as 0x80). All the sprites and custom background cards look to be displaying fine. Clean the cartridge slot and look for bent pins. On the motherboard, look for obvious shorts or visually defective components. Check the continuity between the STIC/GRAM chips and the RA-3-9503 GROM chip, reseat and clean the GROM, and if that fails the next step is to use a logic probe to check which data pin is stuck on U7/U8/STIC/GROM (not oscillating). Check that the 74LS86N logic gate at U17 is working correctly too. - J

The different region/TV standard Intellivisions should all have different model numbers. Eg, the Australian PAL 50Hz Intellivision 1's are model 3668, while the USA 60Hz NTSC is 2609. Your SECAM model is model number 5156. Within each model, there may be multiple revisions (or local mods) of the same board. - J

Yes, the STIC chip allows for 8 moving objects (MOB), the same thing as sprites. Each MOB can be 8x8 or 8x16, and can be single height (pixel height is 1/2 a background pixel) or double height (pixel height is the same as a background pixel). Pixels in MOBs are always the same width as the background pixels. I believe that each sprite is a single colour 1-plane bitmap, which means each pixel can be on or off, ie, either a single sprite colour, or see-through so the background will be shown. You can make moving objects with more than one colour by overlapping multiple sprites in the same position with different colours. The Intellivision can redisplay the same sprites on different scan lines going down the screen with some clever programming to give the illusion of even more objects, a trick known as multiplexing, but this tends to cause sprite flicker. As far as I know, the Intellivision would not easily be able to do software sprites, due to the background card method of accessing the display. - J

In addition to all the different brandings/model numbers, there were several revisions of the Intellivision main logic boards too. Some mainboards are green, some are light tan. - J

You might have a bad/dry/cracked solder joint on the 12V regulator. You could try reflowing the solder on the regulators as a quick fix. But I would definitely replace the voltage regulators by the sounds of it. Don't forget to use a small blob of heatsink compound between the backs of the regulators and the heatsink. When you reflow or resolder the regulators, remove any existing solder and use isopropyl alcohol to clean away any ancient flux so you can make sure the pads are as clean as possible when you apply fresh solder. - J

The static in the audio will very likely just be the volume control dial on the Intellivoice. Clean with deoxit and spin the dial up and down a few times. Adjust the volume so the voices are a similar volume to the rest of the game sounds. As for the freezing/black screening, your power supply board may not be providing enough power under load. Have you cleaned the cartridge slot, power connectors and power switch with deoxit? Check the voltage on the 5V and 12V lines under load. If the voltage on the 5V is dipping too low, it could explain the black screens and crashes. Are either or both of the voltage regulators on the power board getting very hot? If you don't have another power board to swap in to try, a shotgun approach would be to replace the electrolytic caps and the 7805 and 7812 voltage regulators on the power supply board. The regulators should be quite cheap, the 2200uF 25V and 10000uF 16V/25V parts will be a little bit pricier for quality parts (Nichicon, etc). But since these parts are now more than 30 years old, replacing them is probably a good idea. The 7805 5V regulator is probably a good place to start. - J

My PAL 3668 unit gives the standard olive green-brown colour for the title screen background, the same as the NTSC version. I did notice that Thunder Castle when played on a USA unit has a black title screen background, while the PAL Intellivision displays the the default olive colour. However when I changed one of my units to a PAL60 unit, the background changed to black, so this appears to be game timing related, not to do with colour circuitry. There look to be three trim pots on the daughter board on top. I'm pretty sure that is the colour board that generates the video signal. Have you tried the adjusters on this top board? Maybe a previous owner twiddled those pots? Can you get a better detailed pic of the front and the back of the daughterboard that's on top? That would be the colour board. Especially useful would be chip numbers. Or better yet if someone has a schematic...

The INTV System III that I have does not have an RF shield. If they were all this way then overheating would have been somewhat less of an issue.

It's technically the same as they Intellivision 1. After the Intellivision II, INTV corp returned to the original design for the INTV System III. But they are a few years newer, and made from newer batches of GI parts, so might be a little more reliable. One of the units I have that worked all the way with no repairs needed is an INTV System III. - J

I believe that the red connector in this case is the 5-pin AC input connector from the transformer. You can try cleaning that connector with deoxit and see if that helps. Make sure that the pins are making proper contact inside the connector. Sometimes the 2-pin STIC wire can be a red connector too, that can come loose and need attention as well. The junk on the capacitors is indeed glue used to hold the larger capacitors in place. If this glue has disintegrated over time, there may be some stress on the solder joints that requires reflowing. The brown gunk on the solder side of the board is leftover flux from manufacturing. Isopropyl alcohol will get rid of it. I had one power board that had particularly bad flux residue, it's good practice to remove it. As a matter of course for two of my main Intellivision units, I replaced the three electrolytic caps and both the 7805 and 7812 voltage regulators on the power supply board. The SHOEI branded electrolytic caps are generally very good quality but they are over 30 years old now. Replacing these parts fixed a black rolling bar picture issue on one of my units. Your picture looks pretty good - The black shadows looks like it could be some RF interference or fine tuning. Have you tried the unit with an old CRT? Try a better shielded coaxial cable? Manually fine tuned the analogue signal a hair? A certain amount of artifacting (shadows and colour bleed to the immediate left of contrast areas) is normal. - James

I always really liked the disc controller. The number keypad was just OK after getting used to it. I kinda like the bubble top feel. The biggest problem is the side buttons, they are just too small and too stiff for rapid repeated presses. They make games like Nova Blast very difficult, almost impossible to play. I get the feeling that the game designers mostly shared these opinions, as most games use only occasional side button or keypad presses rather than rapid presses. Where rapid shooting is needed, they sometimes came up with ways around it, eg the gave you autofire in Astrosmash.

Use the search function, there is another thread on here where a member had some new-old stock parts to sell, including STIC chips.

Yes that could change things, since you'd be splicing into the video signal before the RF encoding - Have you removed the SECAM daughter card completely? Where are you getting the video colour/luminance from? What colour system chip does the SECAM board use? Do you have a pic of your modded board? The mod is so simple you may as well try it (if you have the parts) - Swap the 4.00MHz XTAL for 3.579545MHz one to get the correct clock rates, and swap the AY-3-8910 CCIR STIC for an AY-3-8900-1 NTSC STIC.

I have had several Intellivisions through my hands, and only one didn't have some kind of issue, and that was an INTV System III. I had to make various repairs on the rest. The Intellivision has a very complex logic board for its time, with lots of ICs. The smaller board with the two big blue caps is the power supply board. It has AC to DC rectifiers, and 12V and 5V voltage regulators. It has a 2 pin connector with 1 wire, and a 5 pin ribbon cable. Be careful with the ribbon cable, it can disintegrate easily. Problems with the power supply will usually result in the console failing to boot at all, giving either a black screen, a striped screen or no picture at all. You can check this board is working OK by checking the voltages at each pin against the back pin on the 2-pin connector. The two large caps can have cracks in the solder, so reflowing those solder joints is sometimes necessary. These caps are usually hot glued to the board at the factory to prevent this happening. Does only Diner cut out in the middle of level 8 at the same place every time? Any symptoms with other games? If this is so, it sounds more like a logic issue rather than power supply, possibly RA-3-9600 SRAM. - J

No, I don't think that this will work. PAL is an amplitude modulated signal, SECAM is frequency modulated. As far as I know, there is only a 50Hz standard for SECAM, whereas PAL has 50Hz and 60Hz variants. - J

Funny this should come up - I just bought this last week. Haven't had a chance to start reading yet, my son is being very demanding that I continue reading Harry Potter to him

You may have a grounding issue with the RF output, or some other short. When you disassemble the unit, check if the shielding has been removed or not. There are 2 adjusters you can get to without opening the shielding, one is for audio and one is for video: If the video adjustment doesn't help, you'll need to crack out the soldering iron and open the shielding. Check around and inside the RF modulator (the lid clips off) for solder bridges or cracks. Most PAL model 3668 Intellivisions have a daughter board that does the colour generation as mr_me says. There are ribbon cables that connect where the AY-3-8915 would go to the daughter board, check these for continuity. The daughter board contains a couple of adjusters on it, and a number of electrolytic caps. The SHOEI caps in Intellivisions are generally good quality, but still at least a visual check for leaked caps is a good idea. You could try replacing the 4.43361875 MHz crystal, as this is the one that generates the PAL colour frequencies (the PAL Inty should have 2 crystals - one at 4MHz for system clock, and one at 4.43361875 MHz for colour subcarrier). Check too that the power supply voltages are correct, in particular the 12V across the back 2 pins on the power supply. - J

It has to be asked - How did you manage to kill two Flashback units? - J

Check the pins in the cart slot are straight and not shorted. Pin 12 is a reset line. Do you have any other game carts to test with? Check the voltages at the 5 pin header with the ribbon disconnected. What does it do with no game inserted, does it still flash or just blank screen? If it still flashes with no game, the reset circuit is fairly straightforward to check. Check cap C26, C9 and diode CR7. Lastly try swapping the STIC.

Very sad news, my condolences to Keith's family and friends. Thanks to Keith for his work with the Intellivision and tending its legacy, bringing decle coded goodness to younger generations. He left his indelible mark on video games history for sure. - James

Yes a few more pics of other games would be useful. If the graphical glitches are restricted to the sprites, it does sound like the STIC is the best place to start, and if that doesn't fix it I would look at the RA-3-9600, then GRAM. A bad RA-3-9600 SRAM can cause all sorts of weird and wonderful crashes and glitches. Make doubly sure that all the cartridge slot connections are clean and solid. Try carefully removing and cleaning the pins of the STIC (and other socketed ICs) and reseating, then if that doesn't help swap the STIC for another. Get some deoxit spray for the cart slot, chip sockets and pins. - J