NetworkSound Here: We traced the issue to assembly tech grabbing the wrong solder spool by mistake (Kester - Water soluble) for this batch of boards. Back to the normal solder and flux cleanup remover, the splitter is working well. The affected small batch of boards have been isolated/recalled. All other issues are also addressed to the customer satisfaction.

H i guess i the black thing in the 4:21 position is a precision voltage divider to scale down 10V to 100mV it might consist of a 199880 Ohm and a 20Ohm vesistor , that are very well matched in tempco and value to give the 100:1 attenuation

Iam a noob at electronics but always willing to learn, i read the esx/emx have a debug connector, i immagine the ER1 ETC. dont have such a thing since you desplser the whole memory chip and put it in a reader, my ER1 is working but has some strange parameter like bug, hard to understand if it is a hardware problem wich you would guess is most likley, but everything else works perfectly and i'm almost convinced it could be some kinda of software bag within the firmware or something, so i was hoping for a way to reflash the firmware or something.

Update: people form NetworkSound watched this and worked with my friends to fix the problem for them. They also said that they will fix the production process.

Thank you very much. I ran into the same problem. The speaker wouldn't turn on, and when turned off, the display backlight was blinking. Inside, I didn't see any signs of damage, all components were intact, including capacitors. I checked the voltages - there was actually 4V on the 5V bus, the other buses were fine. I started looking for information and found your video. I checked the capacitor that you replaced. Mine was also damaged - the capacitance was 90 μF instead of 1000 μF, although it looked fine visually. After replacing the capacitor and checking the voltage on all buses, everything was OK. Now it works.

坏点是什么功能实现？

What is substitution for IC CL2106OH ? KRK ROKIT 5 G4 power supply. Can't find datasheet. Thank you.

Very good video ! If you can help me, I have a problem with my Amp. Same model. After a source change from my daughter with max volume the soft clipping which it was on is failed. What can I do/check in order to fix it by myself. The amp is working perfectly after than incident but the soft clipping is not activated led is off !

the older version is 16-bit which is why it sounded so good unlike the 24-bit which is more high quality but not as gritty and tough

I'm pretty sure that the rack version can record 32/64 channels if you connect it to a daw. It's only 2 channels if you are recording directly to the SD card slot.

For sure I'd contact the manufacturer (if possible) and just point them to this video...very disappointing and ever more so frustrating!

It looks like defective or poor quality PCB material, or perhaps the PCB material was contaminated with something conductive during manufacture. In my line of work I came across circular multi-pin connectors from a well known manufacture that had defective/conductive rubber grommets, in the few megohms to tens of megohms like your PCBs. The rubber had a manufacturing defect so such things can happen. I like the idea of making replacement PCBs, there must be many more units out there that need this repair. Your point to point wiring turned out nicely but no doubt time consuming.

Actual experience: Equipment was used at a seaside location with humid salty air, and salt laden moisture was absorbed into the PCB. Cleanings had some effect, soaking and baking had more effect, but the only permanent solution was to replace the PCBs and apply conformal coating. The PCB material was that tan porous "consumer electronics" junk though.

Wow! makes me think of carbon loaded plastics, like all this black around, but you tested the PCB with nothing else connected I think (will run it again) so these huge resistances are an artifact of the PCB manufacture. Can you stick a bare PCB in the oven 100 C overnight and bake it ? But again the big change with the wired version was the black connectors so I dunno....but personally I would hit Kicad and get one made ! surely less painful than wiring that lot up.

If you have a scrap board available: remove the solder resist on a channel and see what happens. Looks a bit like some bozo put a can of 'anti-static' paint in the machine that applied the solder resist?

Some PCBs show an effect called "Conductive Anodic Filament" (CAF) which reduces the isolation resistance. But it is observed especially at higher voltages. Maybe the PCB contains some impurities leading to a migration of copper ions.

We missed your meticulous investigation on fixing electronic test equipments.

PCB moisture contamination => Put the PCB into ventilated oven and test. If wrong change PCB

Hate to say it, but you get what you pay for. Tell them to buy hand-wired boxes that work, instead of these 'modern' failures-in-waiting.

My guess is that there is moisture in the circuit board.Try to remove all connectors and cook it in an oven at like 140c see if that works ,I've never seen this one before Good find.

Make your own box and call it FeedbackNoLoop 😁

Make new PCBs, once you’ve got them you can repair as many as you need in very little time, maybe even just make your own and not bother with that junk at all.

I would not try to dry the PCBs in an oven because it is quite likely that the problem will reoccur. In my opinion, there are two solutions: replace the PCBs completely with wire connections or have new, high quality PCBs made.

I would try to unsolder everything, then a bath of pure acetone, preferably with ultrasound, then a bath of pure alcohol, and let it dry in the oven at 60ºC for 2 hours.If this fix it, after resolder everything, put some uv top coat.

Maybe the flux wicked up the conductors and is on the other side of the PCB as well and was protected during your cleaning by the connectors? I would try cleaning the board you removed the connectors from again with regular soap and water, if that does not fix it I'd try acetone and if that does not fix it maybe put it in an oven for 24 hours and if that still does not work I'd design new PCB's, very interesting video :)

The damper pedal in my piano with this model is a bit stiff. Is there an adjustment screw that I can loosen a bit?

Tough soldering job - well done! I guess they used cheap PCB material, might be low quality / bad CEM 3.

My first thought was bad vias without proper clearance to the ground plane. It looks like almost every trace goes through a via (on the back of the board anyhow). Really poor PCB quality at any rate. If you do end up redesigning the PCBs and post the files online, it may help out some other people that have those same devices. Because with three bad examples on your bench alone, there a probably thousands (?) of faulty units out there. Either way, glad to see you posting a lot of videos recently. Longtime fan of the channel!

i think to design a PCB for them is a good idea as they are garbage and the used market is probably going to be flooded of that model used but almost brand new not working so your friend if he need more can get them for almost nothing plus the price of the repair

Maybe take the unpopulated pcb's and put them in a oven for a while and see if it dries out any moisture in them

My first hypothesis was hygroscopic flux as well, as I've had it happen before in my multimeter. But this issue must be the related to the boards themselves. PCBs do absorb moisture as well. At the assembler where I work we dry PCBs before reflow soldering if the package has been open for too long. Obviously these boards are just wave soldered, but the same moisture absorption can happen over time, I guess. I've never seen a device fail because of conductive boards before, though. Suggestion: Put them in a small, temperature controlled oven at 60-70C (140-158F) for 24 hrs. See if it makes a difference.

Perhaps contact the manufacturer or go with another one. This is not acceptable.

I have had a LED dimly lit for no reason, but after a PCB wash it fixed it. Don't know why your wash didn't work, unless it's something insolvent with what you washed it with, or the PCB is maybe porous and absorbed something - maybe possible on the edges, but not very likely in the centre -.

Were they made by Tom Evans? 🤡

The problem could be in an inner layer if it's a multi-layer board. It would be interesting to see it x-rayed.

Incredibly poor PCB quality. I think that is the cheapest and easiest way to go. Probably not the quickest however.

maybe the PCB's absorbed moisture somehow? Depending on what kind of material they were made of, I suppose it could be a possibility. If you put them in oven to get the moisture out then....

PCB's becoming conductive is such a frustration. I like your point to point fix, but it is a TON of work. Historically, that's the way it once was done, and worked for decades.

Are you seeing the same resistances across a dismantled bare board? Maybe better make your own boards? You can get xlr type rck cases, maybe make your own?

Bad PCB process. this is not repair. This is REMAKE!!!

If the PCBs in the breakout boxes are bad, what about the PCBs in the mixer itself?

Can this be described as anything other than shoddy design and manufacturer?

Replacement PCBs

Once we used a _no clean_ Flux on a job that required high reliability. It was a nightmare. OC insisted the no clean Flux needed not to be cleaned. It turned out this specific Flux likes to soak up humidity, and then it becomes quite conductive. We measured on unrelated signal trace resistance as low a one kilo Ohm. Try again cleaning the boards, perhaps with Isopropyl in an ultrasonic bath.

My G4 rokit 7 LCD has gone blank but the speaker still powers on and works?? Could it possibly be the same issue and capacitor i wonder...

Nice video

몇년전 우연한 기회에 입수한 QSC 1400, 분해해 보고 나의 설계철학에 가장 부합한 1PCB에 입,출력, 전원만 투입하면 동작하는 가장 이상적인 설계, 호기심에 상위기종 1310, 입수, 결론은 신호경로 최소화로 음이 깨끗하고 순수한음, PCB와 일부부품 고급화만 이루어 진다면, 대출력, 내구성, 가격등 빈자의 마크레빈슨에 전혀 손색없는 최고의 AMP,

Only a Genius can figure trhis out ...Bravo !

replacement for fluke tools is very difficulty, sometimes asking them they are not respond, they want customer througvto the bin and order new one, very disappointed this brand

Thank god for fuses.