psarkissian

Mac OS compatibility notice is right above on the screen.

I've never had to try safe mode.

have it done by a Line 6 authorized service tech, they know what tubes to use and bias to set.

Yes, tubes. When was the last time they were changed out?

It may be a hardware issue. When was the last time the tubes were changed out? Old or failing tubes can pull down on a circuit and create a number of issues. Also the incorrect tubes and bias can result voltage pull-down issues. Tubes choices to use for the DT Series,... DT-50 Series: 12AX7EH Electro-Harmonix approved for the DT50 pre-amps. EL34EH Electro-Harmonix (matched pairs) for the power amps. DT-25 Series: 12AX7B China for pre-amps. EL84EH Electro-Harmonix (matched pairs) for the power amps. Power amp tube choices are crucial, and must be properly biased by a tech or Line 6 authorized service center who knows the product. Don't do this yourself, the shock hazard is too great,... and it hurts when you get electric shock. Leave it to a tech trained who is for this. These valve amps are particular about tubes and tube brands. Do Not use substitutes, No Mesa, Groove Tube, Tung-Sol or JJ or (etc) substitutes. No hot rodding of an already Bogner hot rod amp. Your unit was built way after the tech bulletin range, so that won't be an issue.

-What computer OS are you using? -Is there a USB hub connected to the computer? If so, disconnect it while connecting to Monkey or Workbench HD. -Use a MIDI Uno interface.

Don't go adding a JTAG header,... that would be bad. Don't do that.

:)

Based on tone by known artists (Albert Lee, Maroon 5, and others). And then season to taste.

If it has been serviced, then it was by someone else, have no service history on it. Sounds normal. Takes a minute for the processor to wake up the system and warm up. Typical even with all analog tube amps of old. Very good.

Opto-isolators in MIDI circuits are usually very reliable. MIDI in the DT50 is for connecting to Line 6 Monkey. Be aware that DT Edit is 3rd party app and is unsupported by Line 6. And yes, don't poke around in there.

That trace is damaged. A new jack plate assembly is needed.

No, the FBV and Spider V don't have a Variax Digital Interface (VDI) connector.

Serial number is on the back panel. I would be able to check the service history. The only way for you to see the service history is to buy it, then register it in your account.

Power tube element is failing. Have a Line 6 authorized service center deal with it, replace and properly bias and check the amp. Don't do this yourself, the shock hazard is too great and dangerous.

Use a guitar cable with TRS (tip, ring, sleeve) plugs and not a TS plug. This is an active circuit guitar. Tip = Signal, Ring = +Vdc from battery, Sleeve = ground return. The pick-up film can sometimes interfere with the Model switch. If those do not fix it, then it may be the battery box control circuit itself, LED's showing good battery, but sending a false low signal to the main processor board.

If there was a serial number in the photos, I could look up its age and service history (if any).

If it's not cable impedance mis-match, then that would narrow it down to being single coil pick-ups in a electrically noisy environment. It's the reason humbuckers were created. Might not be hum in the usual sense, but the noise floor overall is higher with single coil pick-ups. People who typically go for single coil like that noise floor,... it's a warm sound. Minimalist use of a noise gate might be helpful. Find the no signal noise floor, then adjust threshold to a low minimal setting for smooth gate transitions.

Sounding more like an impedance mis-match, quality of cable not as well matched to the interface input, the interface input, or both.

What crusinon2 said. Also, lights and other devices can give off their own noise emanations that single coil pick-ups grab. Try to not get too close to those.

Cocked to one side too much and it will bind. Each side adjusts a little at a time, for that kind of bridge post. Looks like the set-up in general needs to be checked out.

He had to send it in,... turned out to be something with the guitar, couple of minor hardware circuit things. Interface and cable checked out fine. Phone help first, to see if it needed a return. Glad It could help. :)

- Using the VDI and the 1/4" output simultaneously? - No, can't fix it, the circuit trace looks damaged. BTW, it's not a resistor,... good guess though. - The jack plate assembly has a longer cable,... it's for a JTV-59. You will need one for a Variax Standard. Check for Line 6 authorized service in your area,... https://line6.com/find/service_center/

https://shop-us.line6.com/hardware/parts-and-accessories/

It's a safety issue. If you damage something, Line 6 will not support it because of the modification. If you get injured, it's becomes your responsibility. Li-Ion batteries are not something to be messed with. Charge/discharge specs have to be correct. There are variations between manufacturers that can cause issues. Use the correct and official battery. In this case, taking the cheap route can be dangerous.