Line 6 DL4 flashing preset LEDs

[Mick Bailey]

I have a DL4 that flashes its preset LED on A B or C when selected. Works fine otherwise. Anyone know why this is?

[doctor]

If you think that this is wrong, perform a hard reset:

Press the far left and far right switches while plugging in the left/mono
guitar input (when the left/mono input is not plugged in, the pedal is powered off).

[Mick Bailey]

Thanks. I tried that when I got the pedal, but no change. I've just noticed that occasionally the tap tempo LED with flash a repeated sequence and then stop. It looks to me like it could be giving an error code, but I can't find any further information other than on the Line 6 forum one of the Line 6 guys said he's seen this when the technicians initiate a diagnostic routine within the unit, but the information is proprietary.

The customer tells me he's also had problems with the pedal flashing the A and B LEDs and it not working. The DC voltages are good and it sounds fine, but without any further info I guess I'm at a dead end with this.

[Mick Bailey]

I've kind of got to the bottom of the problem, though not entirely sorted yet. There's 0.56v AC ripple on C40 that's getting carried through the MAX887 step-down IC and putting 0.46v ripple onto the 3.3v rail. When I'd originally checked the voltages I was looking at DC levels.

The circuit is drawing 135mA - not a great deal, and would expect some ripple given the half-wave rectification. Powering the unit from 9vdc shows it to be working correctly.

So, the ripple on the 3.3v is causing the problem - maybe causing a continuous processor reset. If the level across C40 is normal then maybe the MAX887 is suspect. The line regulation is given as 0.2%/v so I wouldn't expect any significant ripple on the output.

Anyone got any views on this?

[Jazz P Bass]

I find it odd that certain caps are specified as "47uf Tantalum or 220uf Electrolytic".

[effectsbay]

I've kind of got to the bottom of the problem, though not entirely sorted yet. There's 0.56v AC ripple on C40 that's getting carried through the MAX887 step-down IC and putting 0.46v ripple onto the 3.3v rail. When I'd originally checked the voltages I was looking at DC levels.

The circuit is drawing 135mA - not a great deal, and would expect some ripple given the half-wave rectification. Powering the unit from 9vdc shows it to be working correctly.

So, the ripple on the 3.3v is causing the problem - maybe causing a continuous processor reset. If the level across C40 is normal then maybe the MAX887 is suspect. The line regulation is given as 0.2%/v so I wouldn't expect any significant ripple on the output.

Anyone got any views on this?

[ATTACH=CONFIG]34831[/ATTACH]

Hello

This is exactly what I'm experiencing right now? I measured volts on C40 and it was reading from 8.1 to 8.4v and it appears to be 'ok'. Did you ever resolve this problem? I'm hoping to NOT have to replace the MAX887 at U14 to get this to behave properly.

I actually posted about this today: http://music-electronics-forum.com/t40256/

Thanks!
hank