I'm glad someone else said this. Multimeters inject voltage and small current into a circuit to determine the readings. This why it is hard to determine the readings you are seeing without knowing what they are supposed to be. Inductors will always show as low resistances as they are designed to filter/condition current, when used in conjunction with a resistor and capacitor, they create a frequency filter.
Spectacular fix! 😊 Regarding the short/no short; You might be charging a capacitor with your multimeter. (Think of the multimeter as a very small bench power supply.) So the capscitor flows back and makes it look like a short for a moment Thats one of the many reasons its hard to measure things in circuit.
@@StezStixFix i know how it feel , did that on my xbox one x retimer chip did work for a few months till it die again. but on xbox it's a common issue, i do the same freaking ask myself a lot while doing electronics repair/projects can't help myself but try. LOl good video cheers
Couple of things to remind yourself in situation like that; It was already not working when you started. If it is not working at all, you can't make it work less.
You make these calls and second guess yourself thinking it was luck but you are a very intelligent guy and you have learned so much over the years you need to give yourself more credit! I do love how you stay humble tho. Such an awesome guy!
@dudewhoareu Yes, well said. Steve is one awesome fella, but just needs a bit more confidence in himself. "Can I Fix It", 9 times out of ten, he can. Unless it's one of those disgusting "blob chips" or a part that is not obtainable, but that would beat all of us. C'mon Steve, YOU CAN KICK ASS AND FIX IT DUDE. Thanks for your comment Sir. 🤜🤛🫡🫡🫡🫡🫡🫡🫡😊😊😊😊😊
Must be tempting to see if reflowing like that would fix some of the other projects you've had to shelve in the past. Reflow compilation video? :D Can I get a _RE_ flow! ...sorry.
Just want to thank you for your videos. It has been a source of inspiration for me for a while. I've been fixing some stuff like Game Gear, PS1 or NDS and your videos taught me a lot. My brother is currently dying at the hospital after a tough fight against leucemia. Your videos are the only thing I bear watching tonight while I can't sleep
You want to know something? When I first started watching this channel, those patreon songs were such 🔥🔥🔥 that I thought you were paying a musician to make it for you. It probably took at least like maybe around 10 videos before I realized it was you 😂
Steve. I don't know where these beats come from but I love them. I was bobbing my head at work subconsciously with this video on in the background. I forgot I was listening to a song about your viewers for a min.
7:07 your multimeter has to inject voltage and a small amount of current to the system. this can charge up a few capacitors. and resistance is technically a voltage drop. the resistance of your multimeter is pretty high, so there is just a little little current when measuring a resistance. so the multimeter is reading the voltage drop, that's available in the circuit.That's also the reason why often measured resistances go up and down while you're reading them. 9:05 Coils: coils are frequency dependent. Just measuring the resistance is just not always enough. If the leads inside a coils are touching, you still read 0 Ohm, but the frequency related resistance is not the same as before.
Do this as a test, it should explain why you get continuity that disappearsd Grab a random capacitor, test for resistance on lowest range, you should see a near short that changes resistance the longer you are connected, now reverse the leads, you'll get the same When you test for continuity, you are charging capacitors, leave the leads on longer if it looks like a short when testing. You need an LCR meter to check coils, prferably out of circuit
@ 11:44 - it is a measure of inductance, 2R2 means 2.2uH (micro Henries). The resistance across the coil will be very small: the only time (!) the resistance is important is if the coil has gone open-circuit (high resistance).
11:40 xRx values are in micro Henries (μH) Three digit values are in nano Henries (nH) or micro Henries (μH), depending on manufacturers choice First two digits are the value Third digit is the multiplier (or number of zeros added to the value) If there is an R, its acts as a decimal point, and there is no multiplier Examples: 472 = 47*102nH = 4700nH = 4.7μH (Coilcraft) 472 = 47*102μH = 4700μH = 4.7mH (Bourns) 4R7 = 4.7μH
Hey man, great fix! Are you sure that replacement coil fits under that heatsink? The main chip might be overheating after a while for not making appropriate contact.
I would guess if you're getting a short then going back and checking and it's not there, your power from your multimeter is charging either a coil or something in circuit to cause that issue. Iirc, EEVBlog has spoken about such things in the past.
I believe those coils are measured in micro-henries and the generic electronic parts/transistor testers/identifier should be able to verify the value. (The measurement involves determining Inductance of the coil (by using an applied voltage), so a measurement of continuity doesn't really show the value of the micro-henry).
Those Pandora Boxes are junk. Tell the owner to swap it out for a Mister FPGA. Seriously though, those coils are technically inductors and need to be read in inductance/microhenries as opposed to resistance. You’d need to know the microhenry rating to know if they are within spec or not. Resistance measurements only tell you if it’s open or not. Great fix!
Stez, coils are measured in henries, or micro henries, mostly. Coils work using INDUCTANCE. Your meter may have an inductance measuring mode. If not, then inductance meters are available over the internet. Just look out for any meter, handheld, pocket wonders from China, or anything that measures inductance. By the way, inductors are probably better measured out of circuit if possible. Hope this helps(?) Nina ❤️❤️❤️❤️❌️❌️❌️❌️❌️
So the thing where you're checking for shorts and the multi-meter beeps breefly it means that the multi-meter is charging a capacitor, usually when a surface mount component/device (SMC/SMD) like a ceramic capacitor gets cracked it WILL BE a dead short 0 Ohms, Edit: Coils/inductors will always register as short, if it's cracked or O/L it's bad
Steve, best I remember and I might be wrong but when checking coils, you need a meter that reads henry's and micro henry's. Coils are like that wire you use to make jumpers it has a coating on the wire that makes up the coil. Often times, they get hot, melt the coating and dead short. Using a meter that has henry's on it might help you. Idk.
Short no short, charging a cap but is usually visible or switching on a MOSFET so leads the right way around Sir!! Inductors (coils) basically are a dead short at DC so hard to measure unless they are open but at AC its another kettle of fish, you would need to test at about 100 Khz AC. Resetting the trans optical wave differential oscillators time vector circuitry using heat was a cracking idea !.....cheers.
I know your Huapar broke and youse fixed it. Good fix vid that one too btw. I want one as the equivalent Flir is ridiculously higher priced (they aren't worth it imo) but the price for the Huapar has moved further north since your fixed-it video. More like £360+ after vat.
7:15 what is happening when you have the multimeter in continuity (or Ohms), is it's trying to pass a small DC current between the leads. When it can't, it displays OL (Open Loop). When it can, it measures the voltage drop across what's between the leads and translates that to an Ohms value*. That's fine for measuring resistors, but if you measure a capacitor (or a resistor with a capacitor in parallel), it will measure as an effective short until it's nearly completely charged (only then does it become harder to add charge and you begin to see a voltage drop). So it'll beep when the capacitor is discharged, but then stop doing it after a while (or multiple attempts) as the little current from the multimeter has charged the capacitor. Edit: coils can fail in two ways without losing DC continuity: the core can crack, introducing a change in permeability, meaning it resists magnetic flux more, reducing it's efficiency as a coil.The coil you replaced might have mechanically cracked due to whatever (stress due to uneven cooling during production?), which might have been "a problem", but not "the problem". Turns can also short together (a coil is a bunch of thinly insulated copper wire wound tight around a core, if the insulation breaks down, turns become "shorted"), which makes the coil act as a transformer where the secundary side is shorted, iow. all the energy you put into the coil gets dissipated as heat, making it self destruct. You've seen this in earlier fixes. Now read the above 10 times to make sure you don't forget again... (*): or a beep or not. When this happens depends on the brand of multimeter, but, usually a beep means it's less than 25 Ohms and no beep means it's more than 150 Ohms. What happens in between is undetermined: it might beep, it might not. It might oscillate the beep on and off. Again, depends on the brand.
Hi Steve all your videos are amazing 👏 very professional and you are master of the master can you have a look at my Sony MZ-DH10P minidisc player it was working and just stopped working no power to it ? It will be very very good video for RU-vid as there is no videos of this minidisc on RU-vid please kindly let me know thanks waiting for your reply Thankyou
I feel like maybe that wasn't fabric or a hair under the IC, but more like a bug that worked its way under and shorted something out? I would think you'd see debris during the reflow, but 🤷
Cracked joint, or maybe not enough superheat during initial reflow to fully make a joint in the centre (could have been ‘sintered’) reflowing it with direct heat will have remade the connection (obviously)…
Dave I like the way that you know quite a lot but not everything and it seems you just kinda bodge job it, obviously that's not true but it's the way it looks pretty much the way I used to get networks back in line at my work I kinda new what I was doing but couldn't explain to someone what I did. But I always seem to achieve my purpose. Not as in depth as what you do tho dave. 😮
Unfortunately this fix may be temporary. It depends if solder joints broke, in which case it may last longer or if it was internally damaged. In which case it may work for some time, but in a few months it can fail.
The important question is did this board ever work? If it never worked, its a bit of a stretch but maybe the contaminant under the Rock chip prevented all the solder mask balls from making a connection when it was manufactured and the reflow fixes it once the contaminant was removed.
I'm wondering if that dinky little aluminum plate just isn't a big enough heatsink for that Rockchip and it had a broken solder ball from heating and cooling.
haha another great vid ,i actually have one of these and they are great 10000 games on it but i think there’s lots of doubles ,and 1000s ive never heard off just fillers me thinks anyway nice 1 keep this great content coming please you crack me up 👍
Looking for one of these portable screens, which one do you use? I need one that does both USB C and HDMI, oh and most of them unless is a noname one don't seem to have a headphone socket. Sorry to be a pain but you list all your kit but that came on the screen and I thought I'd ask!
U know I've been trying to find the words to why I love watching your vids and can't it so frustrating but I figured out what also makes me feel the same if it helps am a 1980 child and love nostalgia and thing that remind me of those times and if u know u know but I get the same vibe as stranger things lol
13:04 During a lot of time I thought you were saying "let it solder" instead of "leaded solder" as a joke, cause english is not my first language. I think I'll continue to listen to it as "let it solder" if u don't mind 😂. Fantastic job!
Wherever you see a small inductor, with a small black IC nearby - that is a power supply for one of the power rails. You should get a good steady DC on one side of the inductor. The other side will have rapidly switching square wave, which might show as DC on a multimeter. Better to look with an oscilloscope.
Here's a funny story on reflowing chips. About ten years ago I had a coworker ask me if I could fix his laptop. I told him I'd look at it and see what I could do. He tells me it doesn't show any signs of life. Also he tells me that if I fix it, don't look at his pictures because he has nude pictures of his girlfriend. I asked him why would he even tell me that because I wouldn't have looked if I didn't know that bit of info. He was convinced I wouldn't fix it. Long story short I reflowed the Southbridge and it came to life. I brought it back to him and he asked what he owed me. I told him it's free of charge, and by the way, you're a lucky man. 🤣
I'm going to take a guess and say that the manufacturer isn't actually testing them before they leave the factory. I don't think the cpu came loose, I think it was never on properly to begin with
I really like the pandoras boxes but it's a shame they're all mostly made to the cheapest standard possible. If you were to make one from the best available it would be like owing your own arcade. Same goes for emulation handhelds really. Imagine both using the latest Snapdragon and having 16gb or so of ram, good switches and joysticks they could kill off game consoles.
Since the board is under the controllers, maybe an angry player hit the middle of it a few times after losing and broke a connection? Also, I heard you cannot resist as 0 ohm resistor.
The Pandora box because kinda cheap because they removed the fan and heat sink to cool down the main chip. It's also a good idea to add some thermo-paste and a heat sink/fan.
you had your pins of the multimeter the other way around first when you checked the capasitors (6:15) after you removed the heatplate and then you realized it (6:46). you had first the red one on ground and then the other way around. So no trolling only you made a mistake. Can happen.
All capacitors appear as a short circuit, when voltage is first applied, your meter charges the cap when you put the probe on, once its charged no more current flows
Is it possible the chip got so hot that basically it’s disconnected itself? I say this because you’d think it would have a heat sink but that looks more like a clamp to keep the chip against the board.
I know you've already recorded this video and done everything but you shouldn't be testing a circuit board on top of a metal frame of course there's going to be some shorts the board is shorting out on the metal case
