Questions About The Numark MixDeck Onboard DC Port

[TurcoLoco]

Hello all,
I have a Numark MixDeck from 2011. The power supply seems OK but the DC port within the deck itself seems broken or loose.
The device will not power on until the DC connector is inserted and then turned a little counterclockwise then it works but if you touch the cord, poof!

I am guessing the cube shaped DC port on the board is bad and needs to be replace?
Does anyone know what this part is called so I can check on DigiKey or somewhere?
TIA

[TurcoLoco]

I think I lucked out as I believe I located it on DigiKey: https://www.digikey.com/en/products/...T-4S-S/9990090
Can someone at least confirm these are not fixable, meaning I just need to replace the part?

TIA.

[CapLeaker]

If you know the pinout on the jack that corresponds to the wires inside the cable, just unsolder the jack, cut off the plug on the wire and solder the wires to the traces on the board. Cost = Zilch.

As for the jack… I can’t see the bottom of your board to verify the pin arrangement to see if it fits to the PCB.

[TurcoLoco]

Unless I didn't quite get it, what you were suggesting would permanently fixate the power to the unit, right?
I can't do that because it is not mine.

I know the pictures are a bit limited but looking at it from the top the pin locations are a match as well as other details. Data sheet also confirmed the measurements too.

I am trying to not take it all apart because I want to see if something I tried fixed the problem or not, using a special bent tip needle-nose pliers I pinched the metal tabs on the sides inward a bit more.
Not sure if these little tabs located on the side holds the connector firmly in place or not but I want to check to see if that helped before taking the board out.
Thank you!


PS. After 20+ posts, site still needing human verification? Come on!

[CapLeaker]

Aah… well, if it isn’t yours, a new jack it is!

[m1ch43lzm]

Take the board out and inspect the solder joints on that connector, or if in doubt, apply fresh solder to the connector pins; cracked solder joints can also cause the issue you're describing
Also to check if the replacement connector fits the same footprint on the PCB

[TurcoLoco]

Take the board out and inspect the solder joints on that connector, or if in doubt, apply fresh solder to the connector pins; cracked solder joints can also cause the issue you're describing
Also to check if the replacement connector fits the same footprint on the PCB

Thank you. I was going to right after I check to see if the issue still existed or not.
There are like 10-12 screw at the bottom where almost everyone of them had various degrees of cracks where the screw screws into.
I had to do something so, I dropped a little B-7000 around them and for the ones with the big cracks, used mini clamps. One was completely broken off.

Tomorrow should be totally cured then I will reconnect all the cables and check. If no go, then since I will have to take the board out for the new part, I'll double check the solder joints.
The port seemed fairly stable and firm though but you are right, doesn't hurt to check.

Thank you!

[CapLeaker]

Isn’t B7000 flexible glue? Should have used epoxy.

[TurcoLoco]

From experience, it has not been. It is also extremely strong, waterproof, absorbs shocks.
It is clear plus it has very little build-up unlike epoxy. I use epoxy for those tiny embedded nuts on laptop covers that often break off.
If I need to take the motherboard out, there is almost no room between the screw stud and the board hole.
At least for now, I wanted to stay away from doing anything that could prevent me from taking the board apart.

[CapLeaker]

Hmm… gotta be similar to that clear Gorilla glue in the tube. Kinda like shoe goo.

[TurcoLoco]

Never used shoe goo but I do know regular (brownish/reddish) Gorilla expands like crazy.
I really like the B-7000 is a much superior product to Crazy Glue but it is not as fast acting (need to hold the pieces for at least about minute -though head speeds things up)
T7000 is the same but instead of clear, it is black so for black surfaces/components like in this case, T7000 could also be used but it is also a bit slower to dry and seems to dry less firmly.

Well, squeezing in the side metal tab thingies did help but still had to turn the connector for it to power on but still not staying on so ordered a new socket.
Did check the solder joints but they look as good as any I have seen. There was no visible issues or looseness anywhere.
Will update once I get the new part and put it on.

[TurcoLoco]

Update:

Got the new socket yesterday and put it on and everything looked OK.
Put it back together and press the power button and nothing!
I opened the case and from the small opening did a visual inspection and it all looked OK. Press the ON button again and noticed a tiny bit of smoke come from the marked capacitor behind the new socket.
With power removed, checked all the capacitors and the one with the smoke seemed shorted. Removed it and saw a quarter inch long 1mm thick solder piece on one of its legs to a nearby point (marked in one of the attached photos).
I removed that solder stick, cleaned up the glue and checked the capacitor with a ESR checker and everything was within range with no ESR build up either so I put the capacitor back on.
I don't think that was by design but if it really wasn't then was it a sloppy solder job by the factory or someone? Why didn't it cause an issue before? What was that smoke?

I scanned around with my thermal cam and nothing seemed to be heating up or no other smokes or visibly damaged.

Also, just to cover all my bases, I checked the power supply based on the diagram at the bottom of it and not getting any of the voltages shown.
It is a switching power supply but still shouldn't I get some reading? Does this 100% mean the power supply is faulty?
With the old socket, when the owner inserted the power connector and twisted it like quarter turn counter clockwise, the Power button purple LED would lit up and the system seemed to power on as well but it was super sensitive and could easily shut off if touched the connector, PSU or the unit itself.
So, based on these, did the power brick got bricked or is there anything else I can check?

This is a weird power supply with its unique connector so I can't find another to confirm.
Any ideas/suggestions?

TIA.

[CapLeaker]

Dunno… I guess your PSU is dead now. It’s a triple voltage PSU… how did you check it? Did you have the PSU unplugged from the unit and check it?
Either the PSU has a short or it shuts down because it is plugged into the unit and the short is there.
When you got the new jack, did you check if the pin out is the same as the old one was as I mentioned in post #3 before installing it? Only because you ordered something, doesn’t mean you got the right part. Suppliers do make mistakes here and there. Maybe take that capacitor off again and make another picture.

[m1ch43lzm]

Maybe the cable is broken inside the PSU plug? You should get the voltages there

The plug itself is available also at Digikey https://www.digikey.com/en/products/...PPX-4P/9990085

Looks like this PSU can be opened by removing the rubber feet, also seems to be available on ebay, same voltage/current rating but with different plug type, search for SNP-PA51
https://commons.wikimedia.org/wiki/F...-PA51-8655.jpg
https://commons.wikimedia.org/wiki/F...moved-1032.jpg
If you can open it, you can measure the voltages at the output (be very carefui not to touch the primary side when opening it or handling the PCB, you will get an electric shock , the main filter cap will store voltage, up to 170V for some time), to confirm if it's just the cable/plug that's damaged, or the PSU itself

[TurcoLoco]

Dunno… I guess your PSU is dead now. It’s a triple voltage PSU… how did you check it? Did you have the PSU unplugged from the unit and check it?
Either the PSU has a short or it shuts down because it is plugged into the unit and the short is there.
When you got the new jack, did you check if the pin out is the same as the old one was as I mentioned in post #3 before installing it? Only because you ordered something, doesn’t mean you got the right part. Suppliers do make mistakes here and there. Maybe take that capacitor off again and make another picture.

I was checking the PS not connected to anything other than the wall outlet.
Yeah, I really do not understand how the PSU would have gotten fried, was it already damaged even though it was kinda powering on with twisting (def. not normal) or was it something that happened afterwards.
I know my installation was fine and the new socket looked identical to the one I removed. I didn't see pin layout on the tech sheet but the per pin amp rating was more than adequate, other than that not sure.
I should have plugged in the new jack and check but didn't really occur to me.

Maybe the cable is broken inside the PSU plug? You should get the voltages there

The plug itself is available also at Digikey https://www.digikey.com/en/products/...PPX-4P/9990085

Looks like this PSU can be opened by removing the rubber feet, also seems to be available on ebay, same voltage/current rating but with different plug type, search for SNP-PA51
https://commons.wikimedia.org/wiki/F...-PA51-8655.jpg
https://commons.wikimedia.org/wiki/F...moved-1032.jpg
If you can open it, you can measure the voltages at the output (be very carefui not to touch the primary side when opening it or handling the PCB, you will get an electric shock , the main filter cap will store voltage, up to 170V for some time), to confirm if it's just the cable/plug that's damaged, or the PSU itself

Thanks. Not sure if the owner will be interesting in spending any more money as he might have lost confidence in me after a relatively simple DC socket swap failed like this.
I wish I knew what caused it but at this point, I really would like to fix it if I can. This was a side thing and I don't think he is in a super rush.
He said he has spare PS but didn't know if they were the 100% compatible.

I will open the PS and take a look but yeah, last thing I need is to die with a Don King! hairdo!

May other concern is, whether he gets me a spare PS that is compatible or I find out the connector has gone bad, the question still remains: what caused this and more importantly, how can I be certain it won't happen again?
If I have a working PS, then I will definitely check the pins beforehand and also I am in the process of removing the new socket I installed so I can check its pins by connecting it to the PS which would allow me to confirm the layout.

To be continued...

[TurcoLoco]

Oh snap, I removed the new socket, took much longer than I expected, kept wicking solder over and over (which was a red flag in itself).
Anyhow, I clearly put too much solder to the center 4 pins which 3 of them carry voltage and two of them were bridged a tiny bit.

I wanted to make sure the socket had good contact and was solid but this is a thru-hole component where the bottom is not visible at all.
What I missed was the old one had its center pins bent so they used a very little solder almost like tack weld.
Cleaned it all up. Socket looks good but of course cannot tell if it was fried internally. My guess is that likely to have bounced back and fried the PS.

Tomorrow morning I will open up the PS to take a look. I am hoping there is a fuse in there that might have popped or something simple like that.
If I can get the PS working then I will check the socket before installing it again.

I will update when I get things rolling...

[CapLeaker]

Good that you found the short. I guess the power supply still does not work with the short removed from the board. Probably something is fried like a diode on that voltage rail that was shorted inside the PSU.

Another tip. Throw that Chinese solder away and get yourself some 60/40 solder from Kester and good flux. Yes, they cost something, but it is much easier to work with and you will have more success repairing things. Also checking things is the key. For a more entry guy, take as much pictures as you can (every step), they don’t cost nothing and you can erase them later. Also verify your work before powering it back on is very important. That simple step could have saved you the repair on the PSU.

[TurcoLoco]

I really didn't know this was a switching PS with center pins carrying different voltages and even one being ground. That was totally news to me (lack of experience, I suppose?)
I also thought the component would be much more durable/firmly in place if I used a tad more solder and due to the size of the holes, instead of my usual quality Kester (.6mm) I went with some cheapo 1mm one I don't I used before.
I could tell it wasn't flowing as smoothly nor had a shiny finish regardless of using proper amount of flux. So, those are definitely my faults, no denying that.

I really want to fix this as there is no one in my neck of the woods that really work on electronics (probably why the guy came to me).

How should I go about checking the PS? As usual that put that big blob of yellowish foam/glue on where I need to access.
That hardened glue would be very difficult to remove at it is fixated to the capacitors it is sitting on as well.
If I need to remove it, what method would be best? Any other approach would be better?

Dumb questions but I am a noob so gotta ask, red boxed area is my area interest, nothing to check on the other side, correct?
Btw, the green LED actually lights up when plugged in so it seems to be getting power up until that point.

TIA

PS. I have been taking a ton of pictures. I do this all the time and more so with unique stuff like this one.
Though at the spur of the moment, I missed a few like that weird solder piece under the capacitor that smoked a tiny bit.
That solder might have not been an issue but it was odd and I know that wasn't me.

[TurcoLoco]

Interesting, I decided to check the resistors & capacitors for short and the R20 resistor (front left) in the second picture giving continuity beep at 5 Ohm.
Uh, dang, according to DigiKey resistor value checker, that is actually a 4.7 Ohm resistor

Every other resistor seemed OK so not sure which other component to focus on.
I'd appreciate any help you guys can give so I can sort this out without further screw ups.
Thanks.

[m1ch43lzm]

Remove the PCB from the case, then measure on the bottom side where the wires are soldered

Before plugging in the PSU to mains, measure continuity from the PCB side where the wires are soldered, to the other end at the connector
Assuming the black wire is GND, the red, yellow, brown wires are the voltages, you shouldn't assume voltages based on wire color, but maybe red = 5V, yellow = 12v, brown = -12V

Carefully plug in the PSU to mains power, then measure voltages, black probe on GND (black wire), red probe on the red, yellow, brown wires
Don't touch anything outside the red rectangle with bare hands. especially the MOSFET legs or the big filter cap, use proper insulated gloves if necessary when handling the PSU while plugged in to mains

R20 looks like 4.7ohm resistor according to color code: yellow purple gold gold, it's fine