Pioneer DDJ-SR USB not recognized repair

[vlatkojordanov90]

Hi Everyone,

I would start my post by explaining that my DDJ-SR was used only in home environment and wasn't exposed to any smoke, dust or whatever it may affect it, also it wasn't transported that much, just 2-3 times in an outdoor environments far from any liquids or whatever it may harm it, practically it's kept in pristine condition!!

Now what happened next was kinda weird, after some time (and I use the original USB cable provided with it 1.8m!) the DDJ started acting up and wasn't being recognized so I had to unplug the cable, plug it in different port (USB 3.0 and nothing else connected on the hub so it's not power issues!) and until one day I sat on my desktop and powered on the DDJ and I got the same issue, except this time it was it's last one and it never came back!!

I decided to open it up and have a visual inspection by myself as I do have some knowledge in electronics (not expert but I can do basic checks) probed in continuity mode to see if there's any short to ground but couldn't find any shorts so I ordered a new USB B female port and replaced that one (used hot air and wick being careful not to knock off any of the diodes nearby) thinking the connection might be bad and that would do the trick, but no luck. I measured all the voltages down the lines and everything is present, the DDJ lights up just fine but it's not being recognized which points me to a communication error!

Next thing I did was I ordered a new TUSB3200AC streaming chip without realizing that this would have to be re-flashed with the pioneer firmware for it! Of course using hot air I replaced the chip but that didn't helped obviously as it came with empty bootloader and firmware on it.

I soldered the old chip back and I realized I would need to ask for professional help finally lol (now I didn't do this because I thought it might be a simple fix, a blown diode/capacitor/resistor etc. but that wasn't the case. The guy in the shop I guess followed the troubleshooting block diagram provided in the DDJ-SR service manual and he spent more than 2 hours of troubleshooting (not sure what he did in those two hours) but when he returned the board back with an unsuccessful fix I saw that he removed the L13 choke (ACM2012) on the data lines before the TUSB3200AC and wired the traces directly, I guess to see if the coil was doing anything to it?? nonetheless he left it like that he didn't put back the choke so I have to order a new one, however in the SM it doesn't say what's the ohmage so I guess I will have to figure that one out or if someone has an idea please share.

I tried one more shop (official for my region that services Pioneer) and I explained what I did to which he said "well, don't bother bringing it to me since you got that far I can tell you over the phone that'd be a no fix and I would just charge you money for checking something you already done it yourself". I asked if he has a donor board but unfortunately he doesn't have one and that made me very sad!

I bought the controller year after it came out or something, I barely used it and now I need to throw it away or sell it for parts? I don't want to do that! - I mean even in the SM communication block diagram it doesn't even try to fix it thoroughly, bottom line is if X3 oscillator is fine it advises you to replace the motherboard, like really? "UCOM (IC20) is defective. Replace the I/O PCB Assy."

A new motherboard costs ~$400 or something which is the cost of a new controller almost I mean come on guys. Why wouldn't Pioneer agree to send a flashed TUSB3200AC for certain amount of money for example, or a replacement microcontroller?? Why does it have to go to waste immediately? That's kinda sad guys, come on!

So said the above, what I would like to ask everyone is if someone is able to source an TUSB3200AC from a donor board I would be really grateful! I would pay you money for it up to certain amount of course and cover shipping from wherever you are

Please help me fix my DDJ-SR and I will forever remember your name

Sorry for the long post but I wanted to be as clear as possible!



Kind Regards,

Vlatko

[CapLeaker]

Re: Pioneer DDJ-SR USB not recognized repair

I am not much of a help in your case, but I can tell you how I did successfully fix the same problem on different hardware.

Case is basically the same thing, unit itself works, however the computer didn't recognize the piece of hardware. It also didn't make the connecting sound. I quick look at the hardware manager in windows revealed, that the USB hub that is built into the hardware was missing, as a bunch of other audio stuff related to the equipment.

Troubleshooting the problem: This piece of gear was close to the 10k mark to replace, so fixing the problem was priority. I found in the service manual that a specific IC on a specific card was the acting USB Hub inside the unit. I made sure all the connection and traces were o.k, I proceeded to change that USB controller IC and all was fine afterwards.

First you were on the right track, then I think you got sidelined and now are barking up the wrong tree with the Audio amplifier IC. You need to check the IC that's on the USB. I'd say you have data going in, but nothing coming out.

It doesn't really help having no pictures and a service manual to look at.

[vlatkojordanov90]

Re: Pioneer DDJ-SR USB not recognized repair

I am not much of a help in your case, but I can tell you how I did successfully fix the same problem on different hardware.

Case is basically the same thing, unit itself works, however the computer didn't recognize the piece of hardware. It also didn't make the connecting sound. I quick look at the hardware manager in windows revealed, that the USB hub that is built into the hardware was missing, as a bunch of other audio stuff related to the equipment.

Troubleshooting the problem: This piece of gear was close to the 10k mark to replace, so fixing the problem was priority. I found in the service manual that a specific IC on a specific card was the acting USB Hub inside the unit. I made sure all the connection and traces were o.k, I proceeded to change that USB controller IC and all was fine afterwards.

First you were on the right track, then I think you got sidelined and now are barking up the wrong tree with the Audio amplifier IC. You need to check the IC that's on the USB. I'd say you have data going in, but nothing coming out.

It doesn't really help having no pictures and a service manual to look at.

Hey buddy, thanks for reaching out!! Damn that repair must have felt like you climbed mount Everest saving those 10k

So just to quote myself from the text I know it's long so no one would bother reading it in full the TUSB3200AC is actually the USB controller and audio streaming, that's not the amp chip, actually there's no amp at all as it's a midi device, I mean there's an DAC chip but that's just to convert signals and that's far from what I am looking at currently, so as I said in my original post I am aiming at communication error, and the USB chip was replaced but it was empty read above.

You're right I forgot to mention that this was tested on multiple PC's/laptops and same repeatable error.

Not able to upload the SM as it's too large for the forum standards so here's a downloadable link - this is where I have downloaded it from as well: https://elektrotanya.com/pioneer_ddj.../download.html


V

[CapLeaker]

Re: Pioneer DDJ-SR USB not recognized repair

If I read that service manual correctly you'd have to troubleshoot different voltages, diodes, resistors, a crystal and an inductor. It does state that if U16 is defective to switch out the whole board probably for the reason that it needs to be programmed first.

Did anyone check the resistance of R18, R19, R20? If those aren't right, nothing will happen either.

[vlatkojordanov90]

Re: Pioneer DDJ-SR USB not recognized repair

If I read that service manual correctly you'd have to troubleshoot different voltages, diodes, resistors, a crystal and an inductor. It does state that if U16 is defective to switch out the whole board probably for the reason that it needs to be programmed first.

Did anyone check the resistance of R18, R19, R20? If those aren't right, nothing will happen either.

I was following the same block diagram and I checked all components as described in the original post, everything has the correct values, the diodes are not shorted too, well the crystal is not something I could have checked as I don't own an oscilloscope at home but I bet the guy in the first shop did checked it and didn't find anything peculiar happening with it, I doubt that the osc will fail but anything goes, so I'll put that in my order list as well for the choke/inductor as currently there are just two wires directly connecting the lines (I think that's there just to match the USB cable length impedance and the guy tested with shortest cable possible) and see if that'd make a difference but my expectations are low that anything would come out of it

[CapLeaker]

Re: Pioneer DDJ-SR USB not recognized repair

I am not so sure if the other tech looked at this with an oscilloscope. Other than that, he would not have had to straight wire the inductor either. All he had to do was to check the data lines for data while doing some plugging in / out action. If the resistance is off on one of the data lines U16 -> resistor -> inductor -> USB jack, nothing will happen.

You kinda need an o'scope to check the crystal, the USB and the I2C data lines. Check the diodes on the I2C data line between the MCU IC20 and USB IC16. I would expect no action either, if these 2 IC's can't talk to each other.

After this, you A: need a proper programmed replacement IC, or B: a replacement board if you can't find the problem or parts.

[vlatkojordanov90]

Re: Pioneer DDJ-SR USB not recognized repair

I am not so sure if the other tech looked at this with an oscilloscope. Other than that, he would not have had to straight wire the inductor either. All he had to do was to check the data lines for data while doing some plugging in / out action. If the resistance is off on one of the data lines U16 -> resistor -> inductor -> USB jack, nothing will happen.

You kinda need an o'scope to check the crystal, the USB and the I2C data lines. Check the diodes on the I2C data line between the MCU IC20 and USB IC16. I would expect no action either, if these 2 IC's can't talk to each other.

After this, you A: need a proper programmed replacement IC, or B: a replacement board if you can't find the problem or parts.

What you said makes sense, if he used an oscilloscope he would have known if something is faulty by looking at the data lines. So, I won't be going through the hassle of finding an oscilloscope or bother someone. That said I've ordered new 6mhz crystal and a choke however not sure what impedance should I get, so little help would come good since as I said I am a bit illiterate when it comes to such things, I mean is it even possible to calculate the impedance on that choke?

So as you said next steps are to keep trying to find a donor board (going extremely hard) or find someone to dump and re-flash the TUSB3200AC chip.