Thanks, Andy! :)

Great comment.

The errors really do help. I've learned patience through mistakes, you do a great job of demonstrating errors with grace! It definitely serves as a great model!

electronicsnerd I've been trying to champion the chisel tip for years. lol I use a 2.5mm chisel on my Metcal station, and it serves me well for both the tiniest 0402 SMD components, and normal through-hole stuff. Those pointy conical tips seem to come with so many irons / stations, and are half the reason people seem to have so much trouble. I started off with the big shovel tip irons when I was about ten, and they are almost as bad for generally frying the boards and lifting pads / traces etc. Thermal capacity of the iron itself is another issue - many beginners think that because they have a 700-degree F 60W iron that it will necessarily work well on large ground planes or heatsinks. That mainly depends on the ability of the iron or station to supply the heat fast enough, and that's a totally separate thing to the maximum temp, of course. ;)

Chuck Smith I was yelling at the screen too!

But, it's more fun to take it out to the gun range and pump the sucker full of holes until it's a billion pieces. Alas...this channel is about saving the troubled tech. Not caving in to frustration and satisfaction for primitive destruction.

hahaa dudes got more patience than me thats for sure!

Yeah, but Rich @ Thisoldgame makes most or a lot of it.

Interesting!

John's Arcade Game Reviews & Tech That "Ground" connection on the old flyback is likely just for mechanical support. It makes sense just to connect it to ground on the original one anyway, but it's not an electrical requirement. The ground pin on the focus / screen pot is absolutely definitely required though. :p The pots are literally just set up as a voltage divider... (where "G2" is the "screen" voltage.)... www.electro-tech-online.com/attachments/image-jpg.94172/ You can see how the flyback is normally connected to the HOT as well. "+ VCC" on the diagram is the "B+" supply that goes to the primary winding of the flyback. The other end / pin of the primay winding goes to the Collector of the HOT. (On those TO247 transistor packages, the middle pin is very often connected to the uninsulated tab, but not always. On the NPN types, the middle leg is quite often the Collected, but again, not always, so the datasheet should really be checked, even just when replacing a part.) The Emitter is normally connected to Ground, so you can imagine that when the HOT gets a pulse on the Base pin, it switches on, and allows current to flow from the B+ supply, through the primary winding, through the Collector and down to Ground via the Emitter. ;) With the HOT shorted directly to the chassis ground, it could possibly have damaged the old flyback because the current will be permanently supplied to the primary. Almost all modern monitors normally have current-limiting and other protections on the B+ supply though. IIRC, part of the reason it's called a flyback transformer is that the bulk of the HV pulse actually happens after the HOT is switched OFF. This is because the field inside the flyback collapses, and induces current in the secondary windings. It's also because the horizontal scanning of the beam obviously correlates to the pulse on the flyback. See "usage and operation". It has a good explanation of the current pulse on the primary winding vs the secondaries... en.m.wikipedia.org/wiki/Flyback_transformer

John's Arcade Game Reviews & Tech I thought you'd get that flyback in easily after straightening a few pins. lol tbh, I never had any issues with fitting the flybacks. Just need to line the pins up, see which ones might not be on target, bend them carefully with the pliers, then try again. Need to be careful not to snap that ground pin on the pots though. 40:40 - you will often find that most of the pins on the flyback seem to test as "grounded", but you are basically just measuring the windings themselves. Going back to that schematic in my previous post, you'll see that there are multiple other secondary windings for supplying voltage to other parts of the monitor, like the RGB driver transistors on the neck board etc. In many cases, the other end of the secondary windings will be connected directly to the ground plane, and the windings will have a very low resistance of only a couple of Ohms (or far less). So, it's one of the pains of transformers that you can't always use continuity around them. Some of the better meters can do really accurate low-Ohms readings, but even then it's a PITA to figure out what is true ground and what isn't. lol btw, it's better to always twist the strands of wires together before tinning them, and also always add a dab of fresh solder to the joint you will be attaching the wire to. ;) 42:20 - the Focus wire almost always goes directly into the CRT socket, as it's quite a high voltage, so it gives it extra insulation, but there's also a spark gap in there for if the voltage gets too high. The CRT sockets normally un-clip, but some are a pain, and the clips can be brittle on the older ones. I feel your frustration on these vids btw, but replacing parts without being able to properly diag the fault or test the old parts is unfortunately going to result in lots of frustration. It's quite likely that the old flyback was still working too. They are usually a tad more sturdy than people might think, and it's quite easy to build a test circuit to make sure they don't have a dead short on the primary or secondary. I want to visit some day and help fix this stuff. lol I miss working on CRTs, and it still amazes me what a genius invention they are. Even more amazing when you realise what the different voltages do inside the electron gun and tube. ;) The heater in the neck is there to "boil off" electrons, and basically create a small cloud of them. (there is also a Cathode plate just after the heater.) The G1 voltage goes to the "Control grid", which is the first stage which attracts the electrons, and starts them accelerating towards the front of the tube... The G1 voltage is what is driven by the RGB transistors on the neck board - Because the electrons are negatively charged, the more positive the G1 voltage, the more electrons are attracted to that plate, and the DARKER the screen. So the voltages on the output of the RGB drive transistors are actually inverted compared to the brightness of the incoming video signal. (this was news to me when I was first learning. lol) The G2, or "screen" voltage is fixed, and is the next grid along, and helps accelerate the electrons faster still (the number of electrons in the bunch being affected depending on the voltage on G1, of course). The focus voltage is G3, and the voltage is actually lower (more negative) than the G2 voltage, IIRC? The arrangement of the focus grid(s) means it either repels or attracts the electron beam, so either squishing it into a tighter beam, or expanding it. I guess the exact voltage setting of the focus pot depends on the initial width of the beam, the distance from the neck to the front of the tube, and the relative voltage of G2. Lots more info here... lateblt.tripod.com/bit71.txt

I forgot to Sub, I did now... =)

Weird. I see that now. Odd.

Are you talking about the thing at 17:28? Right after he said "I heard some kind of tick sound"? I think that could be dust. It didn't look like a spark to me.

I think you're right. It's dust. You can see it fly off the screen

Right when he says that's, you can hear a tick or spark, along with the flash. Could just be dust, hard to tell.

ebay!

found 'em at Radio Shack too John!

Lol.

Nope, I bought it at Target on day one. Normal price.

You lucked out big time John, struck while the iron was hot!

+scroeffie it is standard res.

Austin LaPlante ¥€$

Bob Marley so long as the bench isnt conductive you are fine. Most of us monitor techs hang the chassis off the back and upside down to probe them with a scope.

Read this. It talks about what you are doing when shorting the tube to frame.: www.andysarcade.net/personal/tech/discharging.txt

John's Arcade Game Reviews & Tech While most of that guide is fair enough, if you really want to protect the HV diode on all flybacks (because most of them will have a diode - they output DC pulses, which get smoothed by the CRT capacitance itself), you should still ideally discharge all CRTs via say a 1K power resistor, just to be sure. The idea is that you are discharging the capacitance on the tube itself though, but you can get a charge on the flyback side too (some might have an internal HV cap), so there's still a slight risk of damage if you short the anode to ground directly. Also, gloves and extra insulation on the screwdriver and wires aren't stupid ideas either - if you've been repairing them for years, then fine, but, as you found out, if the croc clip falls off the chassis, or the wire looses contact with the screwdriver, the arc can still jump to you thumb. Guess how I also found that out once. lol

John's Arcade Game Reviews & Tech 54:30 - the HOT is actually LESS likely to die if the Collector is directly shorted to the chassis ground. ;) If you look at that schematic I posted before, you can see why... www.electro-tech-online.com/attachments/image-jpg.94172/ With the Collector (top pin on the diagram) shorted to ground, it will just be doing what the transistor normally does when it switches on, ie. essentially connecting one end of the flyback primary winding to ground. In that "common emitter" style configuration, the transistor can only ever pull that pin on the flyback down to ground. (the current is only supplied to the flyback at the other end of the primary winding, ie. on a different pin.) The only other problem is that shorting across the collector and emitter means that the flyback will be getting constant current from B+ through the winding. Well, until the PSU hopefully shuts down. The pulses to the HOT (and thus through the flyback primary) are normally quite short, so the average current isn't that high. But, if the HOT collector is shorted to Ground, the PSU should detect the over-current, then shut down rapidly, hence the ticking. I think you're probably right though - the old flyback might have had a dead short on the primary, and that's why the original HOT failed, and also why the new one did when it was tested briefly. (you can get shorts between different windings too, and that's never a good thing. lol)

#SOON

#yes #arcadesarefunbutiwanttoseehowyoufixanEMpinball

Luzur ME TOO

Yeah, for sure! It's super cool. A lot like the trench in Star Wars.

Maxx Fordham He did start saying it correctly for a couple episodes a while back, then he reverted to "pull-it" haha

Heheh, give me the links and times then, so I can hear them.

I don't know if I could ever find it again.. Might have been during the jump bug restore

Haha, oh, well that's way back there!

+Brian DuBose I never give up. :) We will get it!