Pioneer DDJ-SR USB not recognized repair - Page 1
Forum section: electronics / repair

author: vlatkojordanov90
author_rank: Newbie
timestamp: December 01, 2021, 11:34:49 am
content: 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 arePlease help me fix my DDJ-SR and I will forever remember your nameSorry for the long post but I wanted to be as clear as possible!Kind Regards,Vlatko

author: KevinA
author_rank: Regular Contributor
timestamp: December 02, 2021, 08:09:49 pm
content: Service manual on Electrotanya.Section 5, repair diagnostics.Section 6, self diagnosis and test routines.

author: Audiorepair
author_rank: Frequent Contributor
timestamp: December 02, 2021, 08:30:34 pm
content: Unfortunately the Service Manual only goes to prove the hopeless situation here.The USB socket is directly connected to a USB controller IC, that cannot be replaced without somehow being able to program the new IC.I have never actually come across this situation, pretty much every case I have seen of any unit not being recognised over USB has been down to a damaged USB socket, that can usually be replaced.(Firewire faults, on the other hand, often similarly destroys the firewire IC the firewire socket is also directly connected to, but replacing this chip usually solves the problem, it doesn't need to be programmed)Edit:It should be noted here that USB design protocol demands that any short between any of the USB connector pins should be tolerated indefinitely by the connected circuitry.Thus, USB circuitry is generally very reliable under fault conditions - change the USB socket and all is good again.Firewire plugs can be forced upside down into sockets, and this condition immediately blows up the firewire IC due to power going into stuff that blows up.That's really rather a crap design IMHO.

author: vlatkojordanov90
author_rank: Newbie
timestamp: December 03, 2021, 12:37:21 pm
content: Hi Guys, thanks to both for jumping in!!Quote from: KevinA on December 02, 2021, 08:09:49 pmSo basically I was going top to bottom over and over in the service manual since day one and I did went through the troubleshooting diagram in section 5, specifically for the comms error and that led me to take actions step by step by diagnosing the componetes listed as I described in my main post.section 6 didn't do much as the device is not being recognized at all, I tried "service mode", "firmware mode" and "factory reset" of course but that didn't helped at allQuote from: Audiorepair on December 02, 2021, 08:30:34 pmIt is weird if a short did this to the IC!! plain stupid to be honest, and I think I was being careful enough not to damage the port behind but it may have happened without me noticing - thinking this thing is too damn fragile, what if it happened during a performance :OStill mad at Pioneer for not being able to source a programmed IC, I mean, if it's a "security" thing to protect themselves against competitors I mean anyone that has access to internet could have easily spent $300-$400 on a 52pin TQFP programmer and dump whatever is on that TUSB3200 chip so not really sure what's the deal there. This feels like sending your iPhone to an apple repair store and the only possible outcome of that is - well we all know it, we need to replace your motherboard lol....So... my next steps are:-Figure out what's the impedance on that L13 choke (ACM2012) that the first tech removed and order one via AliExpress.-Order a new 6mhz crystal to replace X1, probably I'll order a replacement for X3 which is an 8mhz since that's what it states in the TS diagram. Not sure if the tech checked them on an oscilloscope so since I don't own one the easiest way to go is to replace them.-And finally be persistent to find a donor board and replace the IC16 the TUSB3200AC chip which goes damn hard as there seem not to be many out there.It might take some time for the spares to arrive as I order them via AliExpress so I'll keep myself silent for some time on this thread, but if someone has anything more interesting to share please go ahead I am all ears! eyesCheers,V-

author: Audiorepair
author_rank: Frequent Contributor
timestamp: December 03, 2021, 01:21:26 pm
content: The datasheet for the IC doesn't show any chokes, just the same resistors Pioneer use, so perhaps they are not strictly necessary, or at least not for testing purposes.pg 47https://pdf1.alldatasheet.com/datasheet-pdf/view/29306/TI/TUSB3200AC97.html

author: vlatkojordanov90
author_rank: Newbie
timestamp: December 03, 2021, 02:49:27 pm
content: Yeah I saw the same earlier, they don't reference any chokes on the data lines. Not sure what pioneer engineers tried to accomplish here, smoothing out any ripples or?

author: Audiorepair
author_rank: Frequent Contributor
timestamp: December 03, 2021, 03:32:02 pm
content: Maybe helps to keep it within the EMI levels required?