djlotus Posted February 2, 2017 Share Posted February 2, 2017 Been while since I've been here but I am hoping someone can help. Similar to http://www.digitalvertigo.co.uk/forum/index.php?showtopic=39832&hl=rane I am trying to repair a ttm 56. My problem is a bit different though as I have no idea what could be wrong. The mixer won't "mix". Any input coming into the mixer is routed directly to the outputs and the faders have no effect at all. The transform switches work properly as do all of the audio controls (gain, volume, eq). Another symptom is the PGM lights act erratically. Sometimes they "go to the beat" and sometimes they are just doing their own thing or not working at all. I have tried several things to fix the issue:swapping the faders arounddisconnecting the faders one-by-onedisconnecting all of the fadersdisconnecting the PGM boardunplugging everything except a single inputtaken all boards and connectors out and checked for signs of damageNone of these things, or combination of these things help. Rane support is MIA after being sold to inMusic and I fear they are gone forever. Web searches have come up empty with the exception of adjusting the hall sensors. I have not tried this because the odds of all 3 faders getting misaligned at the same time is slim to none. Any ideas or suggestions? I should add that last year I installed new fader blocks which Rane sent me, but the mixer worked perfectly for months after. Quote Link to comment Share on other sites More sharing options...
Jam Burglar Posted February 2, 2017 Share Posted February 2, 2017 Just out of curiosity, have you tried calling Rane HQ in Washington? After the sale they swore up and down that they were still offering service and whatnot, left a phone number on DJ Worx, etc. That being said, the warranty is long gone on the 56. Even before the sale the Rane factory told me they were no longer servicing them (although this was after the announcement and before the sale so maybe they were just pushing me off because of that). I have some schematics if you can't find them online but beyond that I'd just be throwing suggestions into the wind. Did you check all of the ribbon cables for good connection? That would be an easy place to start. Quote Link to comment Share on other sites More sharing options...
Guest rasteri Posted February 2, 2017 Share Posted February 2, 2017 Sounds like you have a problem on the 5v power rail. Check the 5v regulator (Q3 on the bottom PCB). (btw, here's the full ttm56 schematic with the pages missing from the one on the rane site - https://drive.google.com/open?id=0B7FEmphzxtnxdW5CWkllTGZJNEU ) 3 Quote Link to comment Share on other sites More sharing options...
djlotus Posted February 3, 2017 Author Share Posted February 3, 2017 Just out of curiosity, have you tried calling Rane HQ in Washington? After the sale they swore up and down that they were still offering service and whatnot, left a phone number on DJ Worx, etc. That being said, the warranty is long gone on the 56. Even before the sale the Rane factory told me they were no longer servicing them (although this was after the announcement and before the sale so maybe they were just pushing me off because of that). I have some schematics if you can't find them online but beyond that I'd just be throwing suggestions into the wind. Did you check all of the ribbon cables for good connection? That would be an easy place to start. Tried calling. No answer. I had great experiences with their customer support in the past but, as of Sept. of last year, nothing. I saw their support admins were back on their forums so I posted there as well. I don't expect much from them on there though. I have the schematics that came with the mixer and the ones available on their site. They are pretty difficult to follow though as they aren't in the block format I am used to and there are no ratings for the components so testing them is not an option. I checked all the ribbons for proper fitting and signs of failure but found nothing. Same goes for all the boards/connectors. Sounds like you have a problem on the 5v power rail. Check the 5v regulator (Q3 on the bottom PCB). (btw, here's the full ttm56 schematic with the pages missing from the one on the rane site - https://drive.google.com/open?id=0B7FEmphzxtnxdW5CWkllTGZJNEU )I will look into this when I get home tonight. I'm hoping the docs you link to have more info than I currently have. ---I absolutely love this mixer and hope I don't have to sell it for parts. Anyone know off-hand if the 56s or 57sl share components with the 56? Would make locating parts easier. Quote Link to comment Share on other sites More sharing options...
evil98 Posted February 3, 2017 Share Posted February 3, 2017 sorry can't be of much help here but taking notes for the future I'm constantly on the look out for parts so if I come up with anything Ill let you know. Quote Link to comment Share on other sites More sharing options...
djlotus Posted February 3, 2017 Author Share Posted February 3, 2017 sorry can't be of much help here but taking notes for the future I'm constantly on the look out for parts so if I come up with anything Ill let you know. I'd appreciate that and I will do the same in return. I just got home so I'm going to be digging into this. I'm going to start with the power supply and work my way in. Quote Link to comment Share on other sites More sharing options...
Jam Burglar Posted February 4, 2017 Share Posted February 4, 2017 Sounds like you have a problem on the 5v power rail. Check the 5v regulator (Q3 on the bottom PCB). (btw, here's the full ttm56 schematic with the pages missing from the one on the rane site - https://drive.google.com/open?id=0B7FEmphzxtnxdW5CWkllTGZJNEU ) Thanks for posting that. I was looking at the schematics earlier and couldn't find the faders. That explains why. Quote Link to comment Share on other sites More sharing options...
djlotus Posted February 4, 2017 Author Share Posted February 4, 2017 (edited) Sounds like you have a problem on the 5v power rail. Check the 5v regulator (Q3 on the bottom PCB). (btw, here's the full ttm56 schematic with the pages missing from the one on the rane site - https://drive.google.com/open?id=0B7FEmphzxtnxdW5CWkllTGZJNEU )Well, I have checked the board. Not sure how familiar you are with with what voltages should be present and where. I have 9v present on both sides coming from the transformer. That makes sense because its a 18vct. When I get to the 5 volt regulator and I have 2.5v to the input, 0 to output, and 0 to adjusted. Not sure how to tell if that's wrong. I think it is since that circuit is supposed to have 5v once it continues past resistor 384. Another thing I'm noticing is that the other regulators are registering 0 volts on all three pins. I am measuring everything to the line side of the common circuit inducer. Not many answers there I can figure out. Any more ideas? Edited February 4, 2017 by djlotus Quote Link to comment Share on other sites More sharing options...
Guest rasteri Posted February 4, 2017 Share Posted February 4, 2017 Thanks for posting that. I was looking at the schematics earlier and couldn't find the faders. That explains why. BTW, If anyone has page 5 of this - https://drive.google.com/open?id=0B7FEmphzxtnxelBDa2RDS3VoNjg - then you get one special rasteri token to be used however you like. and I mean HOWEVER. Quote Link to comment Share on other sites More sharing options...
djlotus Posted February 6, 2017 Author Share Posted February 6, 2017 Any chance you want help me a bit more troubleshooting this thing rasteri? You knowledge far surpasses mine. Should I start by replacing the voltage regulator given the voltages I stated in above post? Quote Link to comment Share on other sites More sharing options...
Guest rasteri Posted February 6, 2017 Share Posted February 6, 2017 Sorry. You shouldn't be getting 0v on anything, you sure you don't have your meter set to AC? Quote Link to comment Share on other sites More sharing options...
djlotus Posted February 6, 2017 Author Share Posted February 6, 2017 I'll verify when home. It's always a possibility. I am also picking up a nte1929 in hopes that I can use it to replace the lm317 voltage regulator if needed. Only regulator I can find in stock without having to purchase online. Looks like if all the caps and resistors are still good, this regulator should work fine. Quote Link to comment Share on other sites More sharing options...
Jam Burglar Posted February 6, 2017 Share Posted February 6, 2017 If it was me I would probably take it someone who can actually diagnose and repair with some precision. If you replace the transistor and that doesn't work you still want to shotgun the repair then you might try replacing the caps in the power supply. I don't think it's all that uncommon for those caps to fail (happened in my 54 and Chris at Rane told me it's a pretty common thing.) I hate to suggest shotgunning the fix but if you're going to, caps are a good place to start. I almost never hear about resistors going bad. Quote Link to comment Share on other sites More sharing options...
djlotus Posted February 6, 2017 Author Share Posted February 6, 2017 If it was me I would probably take it someone who can actually diagnose and repair with some precision. If you replace the transistor and that doesn't work you still want to shotgun the repair then you might try replacing the caps in the power supply. I don't think it's all that uncommon for those caps to fail (happened in my 54 and Chris at Rane told me it's a pretty common thing.) I hate to suggest shotgunning the fix but if you're going to, caps are a good place to start. I almost never hear about resistors going bad.Are you referring to caps in the transformer casing or the the caps in the power supply circuits? Def some food for thought. I'm trying to work through it on my own (read: not pay for repair) for a little education. I'm pretty handy with things like this so I love learning. This has me a bit baffled though. I am trying to avoid paying to get fixed simply because of the cost associated. There are only a few reputable places within 60 miles from me. All have a minimum $75 drop off/diagnostic fee and average $90-100 per hour for repair. I would guess the least it would cost would be $250-$350. I have plans to buy a new mixer if I can't fix this one soon so this will be a project I work on until it's done. I'll replace every part on the board eventually if I have to. Quote Link to comment Share on other sites More sharing options...
djlotus Posted February 6, 2017 Author Share Posted February 6, 2017 I changed the batteries in my meter and it seems to have helped. I now have +5v out of Q3, +15v out of 10A, and -15v out of 10B. Now I'm trying to trace the circuits around the boards to see if I notice anything wrong elsewhere. Quote Link to comment Share on other sites More sharing options...
Jam Burglar Posted February 7, 2017 Share Posted February 7, 2017 If it was me I would probably take it someone who can actually diagnose and repair with some precision. If you replace the transistor and that doesn't work you still want to shotgun the repair then you might try replacing the caps in the power supply. I don't think it's all that uncommon for those caps to fail (happened in my 54 and Chris at Rane told me it's a pretty common thing.) I hate to suggest shotgunning the fix but if you're going to, caps are a good place to start. I almost never hear about resistors going bad.Are you referring to caps in the transformer casing or the the caps in the power supply circuits? Def some food for thought. I'm trying to work through it on my own (read: not pay for repair) for a little education. I'm pretty handy with things like this so I love learning. This has me a bit baffled though. I am trying to avoid paying to get fixed simply because of the cost associated. There are only a few reputable places within 60 miles from me. All have a minimum $75 drop off/diagnostic fee and average $90-100 per hour for repair. I would guess the least it would cost would be $250-$350. I have plans to buy a new mixer if I can't fix this one soon so this will be a project I work on until it's done. I'll replace every part on the board eventually if I have to. I'm referring to the caps inside the mixer, in the power section of the PCB. I don't even know if there are caps in that external block. Another thing you can do is check continuity at various spots (with the power off). My initial thought was that you had the mixer opened up to swap parts a few months before it started acting up and that maybe something got jostled enough that basic use caused a connection to come loose or a short. I don't fully understand circuit boards (rasteri actually knows what he's dong) but I've caught a few things by poking around. The other thing I've learned is that its super easy to make things worse! Be careful poking around with that multi-meter when you have power to the mixer. It's so easy to slip and send too much voltage to the wrong part of the board. Quote Link to comment Share on other sites More sharing options...
djlotus Posted February 7, 2017 Author Share Posted February 7, 2017 I've traced the circuit as far as I can keep up with the diagrams. Good voltage as far as I can tell. All the caps pass the eye test but, the more I try to make sense of the circuitry, the more I realize it's beyond my abilities.I've been very careful not to make things worse. I'm thinking now I'm going to ship it to someone to look at it.I love tinkering and learning, but this is a problem best left to professionals. I just hate having to pay a hefty price tag to get it fixed. Have to decide now if I want to spend the loot to get it fixed or put that cash towards a new mixer. I'm really going to miss those faders if I get a new mixer. Quote Link to comment Share on other sites More sharing options...
djlotus Posted February 10, 2017 Author Share Posted February 10, 2017 'Im pretty sure, at this point, the problem is in the micro-controller. I have tested for proper control voltage at every regulator, diode, op-amp, etc. I even have the proper voltages at the inputs to the mc. It appears the audio signal is fed through the mc, out to the faders, back to the mc, and out to all of the output channels. The mc they used is now obsolete and I can't find a 54 pin replacement online. I will be parting this mixer out. Thanks for you help everyone. I didn't fix it but, I did learn a bit. Quote Link to comment Share on other sites More sharing options...
Jam Burglar Posted February 10, 2017 Share Posted February 10, 2017 'Im pretty sure, at this point, the problem is in the micro-controller. I have tested for proper control voltage at every regulator, diode, op-amp, etc. I even have the proper voltages at the inputs to the mc. It appears the audio signal is fed through the mc, out to the faders, back to the mc, and out to all of the output channels. The mc they used is now obsolete and I can't find a 54 pin replacement online. I will be parting this mixer out. Thanks for you help everyone. I didn't fix it but, I did learn a bit. Is this that big IC? I was concerned that might be unobtainium if that was the culprit. Easier to replace that whole board than to try to remove and replace that pin with a donor. Quote Link to comment Share on other sites More sharing options...
djlotus Posted February 13, 2017 Author Share Posted February 13, 2017 You are right Jam. The only IC on the bottom board. Found some 6x and 8x replacements but no 54 pin. Got a 61 today.switched out the plastic fader carriers for the metal ones in the 56 and I'll just part out the rest. Quote Link to comment Share on other sites More sharing options...
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