No Signal on Meter

[IggT]

Inherited a DP 24. Installed a new SD card and formatted it. Created a song, did the assignments, connected a known good source, pressed the record buttons, turned up the trim pot, but saw no signal on the meter. Tried all inputs. Any suggestions?

 

[Mark Richards]

If, for example, you've connected a line level source to the line jack of Input A; Assigned Input A to Track 1; Set Input A Trim Knob full left to "Line"; Set your source output signal to an appropriate volume level; and engaged the Track 1 Rec Button (record standby); then you should see a signal level on the Track 1 multitrack display screen meter.

If you then set the Track 1 Fader to unity gain (zero on the scale), and set the Stereo Bus Fader to unity gain (zero on the scale) the Track 1 signal will also appear on the Stereo Bus Meter and be heard on the Stereo Bus.

[Hint]
The more precise the description, the easier it is for us to troubleshoot the problem.

Also note the Trim Knob is not a volume control. As a general rule, the Trim Knob should be set far left ("Line") for a line level source; far right ("Mic") for a mic level source.

I see you've just joined in December 2023. If you haven't yet done so, I also strongly suggest that you take the time to read the "New Members" sticky thread pinned in the shaded area at the top of the "2488 and DP-24/32/SD Digital Portastudios" forum page for very important information about using your DP-24.

 

[IggT]

Using Phil Tipping's guide, I did the procedure on page 46, "How to create a song", the procedure on page 50, "How to load a song", and the procedure on page 90, "Scenario: How record your first mono song." After doing those procedures, I could see, on the Home screen, the inputs assigned to the tracks and the red lights indicating that those tracks were armed to record. Using a mic and cable that was pre-tested through a PA I plugged the mic into an input and adjust the trim pot slowly end to end as I spoke into the mic and saw no signal on the meter. I repeated this with each input. There is no mention in the procedure of needing to adjust the faders to get a record signal.

 

[-mjk-]

Right. The faders are for monitoring the tracks. The record level is set by the level of the source and the trim knob.

What happens when you assign the source to Stereo?

Can you confirm that the machine is in Multitrack mode?

 

[David Porter]

You said you tested the mic and cable with a PA.... just to eliminate this.... can you confirm that you're using a mic that does not require phantom power?

 

[Phil Tipping]

Inherited a DP 24

Not sure if you did a factory initialise as part of the steps you quoted, but if you didn't, I would recommend doing that to reset all settings left by the previous owner.

 

[IggT]

I was using an AKG C1ooo with a battery in it.
I did not did a factory initialise because the previous owner was a member of our band and we had been using it to record before he passed several years ago. The machine has sat idle from then until we got it from his family. I assumed the previous settings (which were our settings) would still be what we wanted. I will try that, though. I don't have my hands on it at the moment. It's at the house where we practice weekly. I posted the original question from there and am working through the member who lives there for now. I live near St. Louis and the weather is not fit for any but the most necessary travel for the next few days. Thanks.

 

[IggT]

I just got confirmation that it is in Multitrack mode.

 

[David Porter]

I was using an AKG C1ooo with a battery in it.

Just because you can - you may want to consider plugging that AKG C1000 in with an XLR and powering with phantom.

 

[David Porter]

And another thing - please pardon for stating the obvious - just trying to help eliminate possible causes from a distance....

I have one of the old AKG C1000 mics.... just remembered that the mic itself has a little on/off switch. Might want to double check that too....

 

[IggT]

We tried it through the PA before we hooked it to the recorder, so yes, it was on. I used to troubleshoot protective systems for power plants and learned not to trust anything as being known good unless I tested it to be good. As we have gone through this, we've redone every step at least once and with different people reading the instructions and performing the steps. I had two people proofread my original post to make sure I didn't leave something out. And, yes, sometimes the most obvious is the one thing overlooked because everyone assumes it has to ok. Thanks for the thought.

 

[-mjk-]

@IggT that sounds frustrating! You just know it's something really small and super easy to over look. I have those in my studio too! All you can do is just keep at it.

I'll share a quick story that I read, about a mechanic that was troubleshooting a car some years ago that was put in his garage for repair. None of the 4 headlights functioned. He went through the entire system from the dashboard switch, through the battery and all the way to the headlights. He just could not figure out why none of the headlights were not lighting up, until he checked the individual lights. All 4 of them were burned out. Apparently the owner had driven the car through 3 light failures and when the 4th one failed, he finally brought it in for repair, of course neglecting to tell the mechanic that they were actually burned out. According to the story the customer just said "the lights don't work" and left the mechanic to figure out why.

 

[IggT]

The frigid weather passed, the ice melted, and the dense fog finally lifted, so the band got together Thursday night. It was Bert, the bass player's first time there since we got the DP24 from the family of our deceased member. He and I had worked together for several years back in the day and have a history of troubleshooting together. I sat with my laptop and tablet and let him man the recorder. We wanted to start as close to right out of the box as possible. We downloaded and loaded the latest firmware. We reformatted the SD card. We re-initialised the factory settings (which we figured was overkill, but we did it anyway). We created a song using current settings. We loaded the song and assigned inputs to tracks. Using a dynamic mic we talked into the mic while adjusting the trim pot. There was no indication of a signal on the meters. We tried this on multiple inputs. We tried assigning the inputs to the stereo bus- nothing. We connected a line signal to multiple inputs-nothing. We tried a condenser mic using phantom power-nothing, until we got to input E. When we turned on the phantom power the machine shut down immediately. It didn't turn off normally, the display went black immediately. We waited a while and turned it back on, and it powered up as it should. We decided to look at the block diagram and we both realized together that the first indication of a signal presence would be the overload light. I took the condenser mic, turned on the phantom power, put the mic to my lips, cupped my hands around the top of the mic, and screamed into it. No light. We were convinced, at that point, that there was something wrong with that input board. We were explaining to the other guys what we thought was wrong with it when a friend of the band came through the door. He saw the machine was on and asked if we were tracking. We explained what we had tried and what we thought was wrong. He said the only thing he knew about them was that people say that if you don't use the original Tascam power supply they won't work right. He asked if we were using the original, and we didn't know. We hadn't set it up. SO, we turned it off and looked. It was NOT a Tascam supply, it was a Behringer. AND, it wasn't a 12 volt DC supply. It was a 9 volt AC supply. Any decent DC powered equipment will have blocking diodes to prevent reverse powering, so the fact that it was an AC supply didn't worry me, but it was being awfully under powered. We went through the whole house and found a 12V supply of adequate current capability, correct polarity, and matching barrel size, powered it back up, and five minutes later had recorded and played back a track. No problem, including with the E-H phantom power.

 

[-mjk-]

[facepalm] Holy cow... yeah that would do it. Glad you got it working and appreciate the followup!

 

[Max Relic]

Thriller story with a happy ending!

 

[shredd]

Kudos to @IggT for sniffing it out - and for the incredible persistence/thoroughness of the process! Many would've given up or sent it off to Tascam-repair.
And extra-bonus-props to the guy that walked in the door and asked about the p/supply. I learned this the hard way...bought a much-anticipated piece o' gear used and it arrived DOA - only to be revealed that they'd sent one a p/s they grabbed out of a box of them, and it was wrong for the unit.
Once corrected - worked like 'butta!!!

 

[-mjk-]

And extra-bonus-props to the guy that walked in the door and asked about the p/supply.

I wonder if he is a forum member....

 

[David Porter]

It's a win-win! You figured it out AND shared the outcome with the forum. Yay. Glad you got it sorted out.