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DT50 finally fixed. Here's the steps I took....
by whiteop on 2010-12-03 14:00:37.4240

If using the HD500 with it:

  1. Download and install Line 6 Monkey program here - http://line6.com/getrelease?rid=3578
  2. Plug a midi to USB cable in the back of the DT-50 and run the other end into your computer. This one works well...http://www.m-audio.com/products/en_us/Uno.html
  3. Now run the Line 6 Monkey and update your amplifier even if it already appears to have the same operating system. It will take about 10 mins or so.
  4. Plug your guitar into the Guitar In jack of the HD500; NOT into the amplifier.
  5. Set up the L6 Link from the HD500 to the DT-50 up using a regular M to F XLR going from the HD500 L6 Link output jack into the back of the DT-50 L6 Link input jack.

Re-flashing my DT-50 fixed my problem.



Re: Is my DT-50 DOA?
by Nick_Mattocks on 2010-12-03 14:49:49.9040

Hi

OK - the amp shouldn't be DOA.  That's a real bummer.  Sorry to hear that,

With the amp off and unplugged, take a look inside the back.  There should be four tubes.  Two bigger ones are EL34's (power tubes) and two smaller tubes nearer the front should be 12AX7 (ECC83).   It is possible that one of the tubes is not correctly seated following transportation

When you turn the amp main power switch on wait about 20-30 seconds and you should hear the relays click into play inside the cab.  At that point you should be able to turn Standby on and the amp should make sound.

Flick the amp to Class A mode, it should hum like a Class A amp.   There should be a slight hum through the speakers when the Standby switch is in the On position.

Check the 32mm tube Protection fuse is intact - replace with the exact same type and rating as necessary

If the tube protection fuse has blown - it may indicate a power tube problem or maybe just a power surge caused it to pop.

If you still aren't getting any sound through the amp, try plugging your guitar directly into the Power Amp Input which should at least give you some signal

Nick



Re: Is my DT-50 DOA?
by whiteop on 2010-12-03 14:54:42.9440

Nick:

The amp does come on. All the lights and relays come on plus you can see all 4 tubes glowing. Just no sound AT ALL. I'm pretty sure I've done everything that a reasonable person would do to check plus I was trained as an electronic tech in my earlier years. I'm waiting to hear back from Guitar Center investigator on this matter. I'm one too by the way just a different field...;)

Thanks anyway.



Re: Is my DT-50 DOA?
by spaceatl on 2010-12-03 15:12:23.9110

Sorry to but in...Did you check the speaker lead? Maybe one of the QDs slipped off...Also test the speaker itself...You can do this with a 9 volt battery...pull the speaker plug and tap the battery contacts on the Sleeve and Tip...Tip should be the positive...If the phase is correct the speaker will move out on contact...If you don't hear anything, it could actually be the speaker itself that is the problem...anyway...just thinking outloud here...

EDIT: Oh I see you checked the connections...try the speaker test just to be sure it works...



Re: Is my DT-50 DOA?
by Nick_Mattocks on 2010-12-03 15:30:15.6810

OK - sorry didn't realise you were electronics trained.  Sounds like you worked through everything already.  I work with computer systems and their users in my day job, so again a different field from this

The tube protection fuse is accessible at the back BTW

Good luck.  I hope you get it resolved soon.

Nick



Re: Is my DT-50 DOA?
by spaceatl on 2010-12-03 15:41:15.0350

I think there might be another fuse...My SV MK2 blew a power tube shortly after arriving...The rear protection fuse was fine...To my surprise, I got no sound at all after I stuck the new tubes in it...It turned out that there is a plate fuse on the Power amp PCB in the Spider Valve...I would tend to think that the DT-50 probably has one of these also...When this plate fuse is blown, all the tube heaters light up and they look like they are working...only the plates are turned off...I am not 100% certain of this in the DT-50 as I have yet to open mine up...But I tend to think that it might have one since the same cool dude designed it...



Re: Is my DT-50 DOA?
by tommy1170 on 2010-12-03 15:43:32.6810

This happened to me the first time I plugged in my DT50 and I was bummed.  However, good news, try this.  Let the amp warm up for a couple of minutes then turn it on.  Plug in your guitar to the high inputs and make sure the guitar volume is turned up.  Now, turn EVERY SINGLE knob on the front, EXCEPT for the volume knob up to 10.  Then turn up your volume knob and see if you get some sound.  My amp came with all the controls (i.e., drive, bass, mid, treble, presence, reverb, ch volume) turned to the "zero" position.  When I plugged in I got no sound and was horrified.  I then turned up all the knobs and "presto" there was the sound.  This was a one-time only issue.  I know this sounds very basic and you may have already tried it but if not, give it a shot.  That's what happened to me and mine works fine.

Tom



Re: Is my DT-50 DOA?
by whiteop on 2010-12-03 16:04:11.5730

Tommy:

Your method worked the first time but not the 2nd time. I think I have a bad amp. I am sooo disappointed...;(



Re: Is my DT-50 DOA?
by Nick_Mattocks on 2010-12-03 16:51:35.0590

spaceatl wrote:

I think there might be another fuse...My SV MK2 blew a power tube shortly after arriving...The rear protection fuse was fine...To my surprise, I got no sound at all after I stuck the new tubes in it...It turned out that there is a plate fuse on the Power amp PCB in the Spider Valve...I would tend to think that the DT-50 probably has one of these also...When this plate fuse is blown, all the tube heaters light up and they look like they are working...only the plates are turned off...I am not 100% certain of this in the DT-50 as I have yet to open mine up...But I tend to think that it might have one since the same cool dude designed it...

Yes that's right - I took a peek inside mine last week and there are other fuses inside.

Nick



Re: Is my DT-50 DOA?
by tommy1170 on 2010-12-03 17:02:40.9270

Great news WhiteOp!  Glad this worked for you.  I have officially made my first "real" contribution to the forums.  The people and L6experts on this forum have really helped me out with questions and issues I have had over the past few years and I am only now "stepping up" to see if I can provide some useful bits for others.  Glad to have helped you out and enjoy your new amp.  It rips!!!!

Tommy



Re: Is my DT-50 DOA?
by Nick_Mattocks on 2010-12-03 17:05:10.2780

That's excellent news.  Well done.  An easy mistake to make - we've all done it or something like it



Re: Is my DT-50 DOA?
by spaceatl on 2010-12-03 17:57:29.9040

speak for yourself Nick...I have never done that...not :-)...btw I just finished modifying my Dt50 and now it goes to 11...it's 1 louder and all it took was a little paint pen... :-) nice one Tom!



Re: Is my DT-50 DOA?
by Nick_Mattocks on 2010-12-03 18:11:17.7500

C'mon space you must've done something daft at some point in your long illustrious career LOL   No-one's that perfect.... are they?

Oh yeah - I remember when I first got my POD 2.0 after having borrowed my mate's POD 2.0 and successfully using it for a couple of days - I don't know why but I was convinced that the input jack was on the side it wasn't and because I hadn't put my specs on I couldn't see the word HEADPHONES on the 'guitar input'.   Oops! Yep how stupid did I feel when I realised after nearly a full hour of cursing and swearing, so yes I was speaking for myself LOL.  Oh how we laughed.......

You got anything you want to confess?  

PS is your DT50 really 1 louder than mine?  Where do you get these paint pens?



Re: Is my DT-50 DOA?
by spaceatl on 2010-12-03 18:20:04.7860

the capacity of a single post couldn't possibly capture them all...One that got several times was when I switched from the Flex3 to the SVmk1...one my flex I generally have all the patches set with a vol min of 80% or so...the boost trick...I was in the habit of putting the heel down on the shortboard volume pedal for a couple of years...I would be there getting ready for sound check and nothing coming on...plugging my loop in backwards...just too many...yep, my dt50 goes to 11....I now have that little extra to push it off the cliff... :-) btw I am doing the rear bias pots and test points mod pretty soon...gonna do up the mk2 at the same time...sorry about the spelling...I am posting from the iPhone.



Re: Is my DT-50 DOA?
by Nick_Mattocks on 2010-12-03 18:47:43.0750

Noooooo..ooo.oooo.oooo.....

You can't push it off the cliff..... wait!  I'll get some mattreses to put at the foot of the cliff.  Which cliff would that be and when?   I'll be there to catch it....   Don't forget you will need castors on that baby to get it to the top of the cliff!..... Nothing wrong with your spelling.  It's 2:45am - got to go to bed or I'll not be able to play around with my HD500 and DT50 tomorrow.

Nick



Re: Is my DT-50 DOA?
by whiteop on 2010-12-03 21:12:06.6450

Nick:

The problem returned and now Tommy's method won't even work. Oh well I have a good Rivera Slavemaster that's 100 watts and it has all the bells and whistles. I'll just use it at church. I don't know if I can trust the reliability of the DT50 now which is sad because I had expected it to be a great amp.



Re: Is my DT-50 DOA?
by Nick_Mattocks on 2010-12-04 02:03:55.4710

That really is bad news and a real shame.  I'm really sorry to hear that.   I can tell you are gutted - and rightly so.  To have the build up and excitement to have it fail is disappointing.

I seriously wouldn't give up on the DT50 just yet if you can hang in there with a replacement as it really is a gorgeous sounding amp when working.    It probably is a tube issue IMO but even so that should not happen really, however your amp was made in China and transported with all tubes in situ to the US and then to GC before being transported out to you and what we can't know is how gentle a ride that was or wasn't.

GC will sort it out for you I'm sure.

Best of luck

Nick



Re: DT50 finally fixed. Here's the steps I took....
by jchokie94 on 2010-12-25 14:02:54.4650

Just got my new DT50 212 today for Christmas and I have the exact same problem you had.  When I first powered it up after about a 10 second delay I heard a few clicks, left it in standby for a few minutes and then turned it on.  Nothing!  No hum, no hiss, nothing.  I tried the "turn everything all the way up" method as described above and still got nothing until about the 4th or 5th time I did it.  Then, I played it for about 20 minutes through the front of the amp and then another hour or so with the HD500 (another Christmas gift - who's got the best wife ever?).  After a break for lunch I came back to have another go and now it's back to nothing again.  I don't have a USB MIDI cable, so I have to wait until tomorrow to give that a try.

By the way, this is my first tube amp.  How long before the tubes start to glow?  It's been sitting in the 'ON' position for about 30 minutes and I don't see any signs of life on the back side.

Is there more to this problem than a firmware update?  Seems like an awful lot of money for something that I have to fix right out of the box.

Any other suggestions?  Should I try the firmware update ($40 cable) or just to a clean swap?

Thanks,

John



Re: DT50 finally fixed. Here's the steps I took....
by whiteop on 2010-12-25 16:52:41.3660

I'm embarrassed to admit it BUT what it turned out being was that I figured out that you don't plug into the front of the DT50 when you use it with the HD500. You just use the L6 link And hook them up using a regular M/F XLR cable. That was all it really turned out to be I think. It was a very DOH (and head slapping) moment for me... lol



Re: DT50 finally fixed. Here's the steps I took....
by jchokie94 on 2010-12-25 17:12:14.4310

I honestly hope it turns out to be the same for me, but it sure is funny how my symptoms matched yours precisely.  I am going to goof around with it some more to see what I can do.  I have tried the L6 Link and straight from the guitar to the front of the amp.  Both worked at one point.  Now it's neither.  Here's to hoping I can have a DOH moment too...



Re: DT50 finally fixed. Here's the steps I took....
by jchokie94 on 2010-12-25 17:45:43.0200

Should any or all of the tubes be glowing?  They all seem to be seated properly.  Power and Standby are in the "ON" position, but I don't see any glow on the tubes.  I have no sound whatsoever.  Still no hum, hiss, or whisper of a sound even with everything turned up.

I can get some clicks when I switch topology, etc.  But that's it.

Any thoughts?



Re: DT50 finally fixed. Here's the steps I took....
by whiteop on 2010-12-25 18:54:14.3120

Plug into one of the front input jacks with a reg patch cable and guitar without the HD hooked up. If you can hear it you know it's not the amp; it's how you have your HD hooked uo. Try the L6 link with the DT50 and your HD; no patch cable should be plugged into the amp when you use the L6 link.



Re: DT50 finally fixed. Here's the steps I took....
by Nick_Mattocks on 2010-12-26 05:40:57.2330

Hi

The clicks you can hear are the internal relays and these will change whether the amp is in standby or whether it's turned on fully.   If the power amp is working you should hear some pops through the speaker when you change topologies or the class mode of operation.  If you get no pops, then I would say there's a good chance that a fuse has blown or that your speaker is not connected properly.

There should be some signs of life and the tubes should have a faint glow from the heaters in both standby and full-on modes.  If the heaters aren't glowing, there is a chance that the heater circuit fuse has blown for some reason - maybe an intermittent power surge, and if this is the case it will need to be replaced with a good one of exactly the same type and ratings.

A dodgy tube might cause the heater circuit fuse, the tube protection fuse or the mains fuse to pop in which case you would need to replace any blown fuses and the dodgy tubes.  Your amp is brand new and so shouldn't have any dodgy tubes, but the fact is that it might, due to the ride it may have had from China to your doorstep.  No one can guarantee that the sea will provide a smooth passage every time.

Nick



Re: DT50 finally fixed. Here's the steps I took....
by jchokie94 on 2010-12-26 08:12:51.7380

Thanks Nick.  This one really has me baffled.  I understand the clicks are from the relays (normal), so something internally seems to be working when I change the respective settings.  However, I get absolutely nothing from the speakers under any circumstances.  No pops, clicks, hum, hiss, nothing from the speakers.  I can have everything on the amp turned wide open and the speakers do nothing.  It was the same way when I turned it on for the first time.  I followed the steps the one gentleman recommended before (turn everything to 10) and after a few tries, the sound ramped up (slowly like the volume was being turned up).  I played straight into the amp and it sounded great.  I then played through the POD HD 500 and it sounded good (lots of tweaking to be done).  Then, I took a break for lunch and when I came back it was dead again.  Since then, I have tried going straight into the amp and through the POD.  I checked the one fuse on the back of the amp and didn't see any signs of damage.  All of the tubes appear to be seated properly but there is no glow in the tubes at all (I did see them glowing when the amp was working).  I was going to try the firmware update, but this has me a little spooked.  Is it too early in the amp's lifecycle to take a chance on keeping it?

Is there anything else to try before I return her to the store?

Thanks,

John



Re: DT50 finally fixed. Here's the steps I took....
by Nick_Mattocks on 2010-12-26 10:01:15.0820

Hi

The front end of the amp which controls the relays would work if the heater circuit fuse had blown.  Obviously the mains fuse is working, and you've checked the 32mm 500mA fuse in the back of the amp (tube protectiuon fuse)  is OK.  The heater circuit fuse is inside the amp chassis, and if this has blown for some reason you won't get any glow from the tubes.  The tubes should all have a faint glow when in Standby as they get heated in this mode to allow the electrons to flow when you apply the High Tension current (HT) by turning the Standby switch to On.  If there is no glow at all (you might struggle to see it in normal light, so it's best to check in a darkened room), it would indicate that the heater circuit isn't working, and a blown fuse would cause this.  It's unusual for the heater circuit fuse to blow, but if one of the tubes had experienced an internal momentary short between the HT side and the heater circuit for some reason the fuse would pop for sure.

It's expected that you will occasionally replace your power tubes as part of normal amp maintenance, and as you may know, replacing the power tubes requires the amp to be re-biased and this requires that the amp be removed from the combo case.  Provided you do this properly and you don't cause any damage, you should not give Line 6 cause to invalidate your warranty - they are more concerned with your personal safety as valve amps in particular can store up a electrical charge which will give you a nasty shock should you touch one of the smoothing capacitor pins and the chassis at the same time.  These normally discharge naturally over a few days.  More importantly tinkering around inside an amp's chassis whilst it's turned on is VERY DANGEROUS and potentially DEADLY if you don't know what you're doing.   However, if you need to check the state of your amp's fuses you have to take the chassis out to take a peek - there is no choice, other than to send your amp back as DOA or take it to a repair centre.

You could update the amp's firmware without the power amp being active.  I always do mine with the amp in Standby.  This is worth a try before you start tinkering with internal fuses.   I haven't personally experienced the firmware causing the amp to go silent and I've probably applied 6 or 7 different firmware updates at least.

Good luck

Nick



Re: DT50 finally fixed. Here's the steps I took....
by jchokie94 on 2010-12-26 18:19:41.6020

I ended up taking her back today.  Don't get me wrong, I LOVED the sound of this amp for the few hours I got to play with it.  However, two things made up my mind.  First, I was obviously turned off by the fact that an amp this expensive showed up DOA.  While I certainly understand "stuff" happens, I just don't think I am ready to drop this much money on an amp I am not positive I can get 20 years out of.  Secondly, I am just some dude who plays mediocre guitar around the house with some backing tracks.  While I am extremely grateful that I have a wife who went to such extremes to surprise me with such a wonderful Christmas gift, I really think this is overkill for my needs.  For me, it's about like buying a Ferrari to go to the mailbox at the end of my driveway.

In the meantime, I have the POD HD 500 to tinker with.  Now I just need to find the optimal way to get it sounding good without the DT50.

Thanks for everyone's help.  For those of you who have this amp, I am sure you will love it.

Regards,

John



Re: DT50 finally fixed. Here's the steps I took....
by whiteop on 2010-12-26 19:20:36.0930

A Fender Super Champ XD or Bugera V22 might do the job then.




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