Members BassDemon Posted January 5, 2006 Members Share Posted January 5, 2006 I have a QSC PLX 2402 that I use in my bass rig.I just hooked up two cabs and found that the cab on channel 2 was distorting and putting out a much lower volume.At first I swapped cables - same problem.So I swapped cabs over and the cab that was fine on ch1 has the same distortion / low output on ch2Hooked both cabs to ch1 and they were fine.It looks like the output on ch2 is the problem. I'm running the amp in parrallel mono with the clip limiter on and the 50hz filter engaged on both channels.I've just checked and all the dip switches are in the right place. could this just be a dirty speakon jack or is it something more sinister ?I'm not far from a service centre but I don't want to pay to have it fixed if it's something I can do myself. Link to comment Share on other sites More sharing options...
Members agedhorse Posted January 5, 2006 Members Share Posted January 5, 2006 Unusual problem, but the first thing I would check (again) is the dip switches. I would also verify operation by putting it in the stereo mode (w/ dip switches) and try each channel independantly. This is the type of symptom you will see if one] of the dip switches ine the parallel mono or bridge mono section are incorrectly set. Link to comment Share on other sites More sharing options...
Members BassDemon Posted January 5, 2006 Author Members Share Posted January 5, 2006 The yellow light for parrallel operation is on. All three switches looks OK. I will try it again in stereo mode and see if I get the same problem. Link to comment Share on other sites More sharing options...
Members agedhorse Posted January 5, 2006 Members Share Posted January 5, 2006 If one switch is incorrectly set, you may not be able to depend on the LED mode indicator. Link to comment Share on other sites More sharing options...
Members BassDemon Posted January 5, 2006 Author Members Share Posted January 5, 2006 This gets weirder In stereo mode Ch1 is fine Change input to Ch2 and cab to Ch2 Volume drops by half (same cab same cables, same input device, attenuators set the same on each channel)It also crackles and cuts out. Back to parrallel mode, CH1 is fine, CH2 output (same cab / cables etc) is half the volume (with attenators set the same)and it's started to crackle and cut out too. How hard is it to replace the speakon output ? Link to comment Share on other sites More sharing options...
Members Unalaska Posted January 5, 2006 Members Share Posted January 5, 2006 That isn't a connector issue, sounds like the guts themselves. I'd strongly recommend getting it serviced before it takes one of your bass cabs out... p Link to comment Share on other sites More sharing options...
Members agedhorse Posted January 6, 2006 Members Share Posted January 6, 2006 Originally posted by BassDemon How hard is it to replace the speakon output ? Why would you possibly think this is the problem? Link to comment Share on other sites More sharing options...
Members BassDemon Posted January 6, 2006 Author Members Share Posted January 6, 2006 Originally posted by agedhorse Why would you possibly think this is the problem? The signal cuts in and out. I had a cab a few years back with a faulty speakon connection that caused the same sort of thing. I will haul the amp over to the service centre next week. Thanks for the help everyone Link to comment Share on other sites More sharing options...
Moderators MarkGifford-1 Posted January 6, 2006 Moderators Share Posted January 6, 2006 Could this be an older model that had the bad ribbon connector? It seems like intermittent cutting out was one of the symptoms of that. MG Link to comment Share on other sites More sharing options...
Members agedhorse Posted January 6, 2006 Members Share Posted January 6, 2006 Originally posted by MarkGifford-1 Could this be an older model that had the bad ribbon connector? It seems like intermittent cutting out was one of the symptoms of that.MG It's possible, though that was not a very common problem, nor did it affect very many units that I am aware of. Link to comment Share on other sites More sharing options...
Members BassDemon Posted January 16, 2006 Author Members Share Posted January 16, 2006 Originally posted by MarkGifford-1 Could this be an older model that had the bad ribbon connector? It seems like intermittent cutting out was one of the symptoms of that.MG Ding Ding Ding - We have a winner Just back from the service centre and it was indeed a faulty ribbon connector. Amp was made in Feb 99 so it's almost 7 years old Cost was $241 (NZ) Link to comment Share on other sites More sharing options...
Members agedhorse Posted January 17, 2006 Members Share Posted January 17, 2006 Great guess. That was a pretty rare pronlem, though after 7 years maybe we are seeing a new round of deterioration? Link to comment Share on other sites More sharing options...
Members ATOMICDOG1 Posted January 17, 2006 Members Share Posted January 17, 2006 I thought I had a bad channel 2 input on one of my RMX2450's. I haven't bothered to fix it yet because I don't use the channel 2 input. It actually had the same symtoms, but when I use it in dual mono mode, it doesn't cut out or distort. only when I'm using the input on channel 2... hmmm, I wonder. Link to comment Share on other sites More sharing options...
Moderators MarkGifford-1 Posted January 18, 2006 Moderators Share Posted January 18, 2006 Originally posted by agedhorse Great guess. That was a pretty rare pronlem, though after 7 years maybe we are seeing a new round of deterioration? I don't think it was that rare - I was looking at a used PLX about 4 years ago and the store (a QSC dealer) told me all about it. It was the whole line, for the first few production runs. They had a list of SN#'s and QSC would pay shipping back AND forth, as well as eat the repair cost. They knew they screwed up, and did a fantastic job of making it right, IMHO. MG Link to comment Share on other sites More sharing options...
Members BassDemon Posted January 19, 2006 Author Members Share Posted January 19, 2006 Originally posted by MarkGifford-1 I don't think it was that rare - I was looking at a used PLX about 4 years ago and the store (a QSC dealer) told me all about it. It was the whole line, for the first few production runs. They had a list of SN#'s and QSC would pay shipping back AND forth, as well as eat the repair cost. They knew they screwed up, and did a fantastic job of making it right, IMHO. MG Hang on a sec - if this was a known issue how come the local QSC agent charged me to fix it. Bastards ! Link to comment Share on other sites More sharing options...
CMS Author Craig Vecchione Posted January 20, 2006 CMS Author Share Posted January 20, 2006 Originally posted by BassDemon Hang on a sec - if this was a known issue how come the local QSC agent charged me to fix it. Bastards ! Possibly out of warranty? How old is the unit, and what is the warranty out of the US? Link to comment Share on other sites More sharing options...
Members agedhorse Posted January 24, 2006 Members Share Posted January 24, 2006 The number of units involved was very small. A bigger problem was the addition of the internal processing modules by folks without the proper IDC tool for installing the ribbon cable ICD ends. That was a problem, though not of QSC's doing. I can't even find reference to the problem in my service support technical paperwork, though I recall seeing something several years ago. Link to comment Share on other sites More sharing options...
Members JohnnyGraphic Posted January 24, 2006 Members Share Posted January 24, 2006 Originally posted by MarkGifford-1 I don't think it was that rare - I was looking at a used PLX about 4 years ago and the store (a QSC dealer) told me all about it. It was the whole line, for the first few production runs. They had a list of SN#'s and QSC would pay shipping back AND forth, as well as eat the repair cost. They knew they screwed up, and did a fantastic job of making it right, IMHO.MG Similar thing happened to the RMX 2450's too (Not sure if affected other models). But, QSC sent me shipping boxes with prepaid labels and paid for the repair and the shipping back too! Not sure if it was ribbon cable or just a cable that was defective...But, they totally took care of the problem!!! Johnny Link to comment Share on other sites More sharing options...
Members agedhorse Posted January 24, 2006 Members Share Posted January 24, 2006 Originally posted by JohnnyGraphic Similar thing happened to the RMX 2450's too (Not sure if affected other models). But, QSC sent me shipping boxes with prepaid labels and paid for the repair and the shipping back too! Not sure if it was ribbon cable or just a cable that was defective...But, they totally took care of the problem!!!Johnny There WAS a known problem with some RMX units, covered under a service bulletin. This was also an early production problem. There was no relation between any PLX and RMX ribbon cable failures at the two lines are built in different countries with different component vendors. Any time you have a connection, you have the possibility for a failure. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.