DD6 clean signal but no delay

[trombleymd]

Hey guys I have a Boss DD6 and when the pedal is on the clean signal comes through but the delayed signal is not present.  The pedal has mostly SMD and I can't really find a schematic but wonder if anybody else has worked on this issue with the DD6. 

[slacker775]

I snagged a broken one off eBay and I have similar symptoms.  The lack of a schematic has slowed my debugging but I have noticed that the chips near the bottom of the board get super hot.   I've started to check the power path to see if something is amiss there but again, lack of schematic has made that a slow process.

[trombleymd]

Yep same here, I must mention that IC6 and Q15 have looked like they been through something.  None of the voltages seem to be out of place but with no schematic that doesn't say a whole lot.

This is how my board looks:

http://img138.imageshack.us/img138/8370/closeupq.jpg

[slacker775]

Mine look very similar.   As if they had either been swapped or possibly fried.   I don't have a known good unit to compare with.  Mine seems to possibly operate fine when setting tap tempo and the like, but no delay ever actually occurs.

[duck_arse]

I was messing with a dd20 recently, and it had an extensive self-test setting, flashed all the flashing and lighting things, and with some boss plugs would do audio setups stuff. is there anything similar in the dd6?

what are the parts numbers that are getting hot on that board?

[trombleymd]

Seiko S-8520E33MC-BJS (IC6) and a 78L05 (Q15).

I checked the voltages (V) and here they are:

IC6:
     Pin1: 9.15
     Pin2: 0
     Pin3: 3.3
     Pin4: 6.5
     Pin5: 9.15

Q15:
     Pin1: 6.5
     Pin2: 3.3
     Pin3: 9.15

data sheet: http://www.mouser.com/ds/2/360/seiko%20instruments_s8520_8521_e-328921.pdf      (IC6)
                 http://img.alibaba.com/img/pb/952/266/682/682266952_244.jpg           (Q15)

From what I can tell it seems like IC6 is functioning just like the data sheet says with an output of 3.3 V and the regulator seems to be fine too except that when I follow the trace it goes to a diode that is from ground to 3.3 and the 3.3 is what ties into pin 2 of the Q15.

[trombleymd]

The components are also not getting hot.

[Suicufnoc]

I fixed one of these a year or so ago, and was able to find the schematic from the service manual.  Ill look tonight

[trombleymd]

I fixed one of these a year or so ago, and was able to find the schematic from the service manual.  Ill look tonight

That would be awesome!!!!

[duck_arse]

the voltages on the reg are all wrong. you want 5V out of a 5V reg, not 6V5. and with 3V3 on the ground pin as ref, it would measure 8V8 at output if it was working correctly.

[trombleymd]

the voltages on the reg are all wrong. you want 5V out of a 5V reg, not 6V5. and with 3V3 on the ground pin as ref, it would measure 8V8 at output if it was working correctly.

Ok cool.  I think I'll order the parts and throw them in and see if that fixes the issue.