Another broken DL4 Pedal thread.

[a1exi]

Hi, I bought a DL4 brand new from the states a few weeks ago. I currently live in England. It worked fine battery operated for a few days, but I left the batteries in overnight with the jack still connected to the input, so by the time it was morning, the batteries ran out. I then went and bought the power supply. I connected it and nothing... recharged the batteries, put them back in and nothing.. knowing that I don't have a warranty as it was purchased from another country, I opened it up. I checked the voltages and I got the following with battery:

D12: 3.3v
D16: nothing (only with power supply)

U14: 2.6v (pin 1 and 5)
U20: 1.6v (pin 8/1 and 5)
U21: 1.6 (pin 1 and 3)

With the power supply:

D12: 9.2v
D11: 9.9v
D16: 0.4v

U14: 7.7v (pin 1 and 5)
U20: 1.8v (pin8/1 and 5)
U21: 1.8v (pin 1 and 3)

Now I know these reading are a bit messed up. I replaced the U20 and got the exact same reading, so that cant be the problem. I also replaced the D16 and it's also the same. What could be the problem?

Thanks,

Alexi

[Enzo]

Can you post or link a schematic?

[zimbu]

At the + of C40 you should have +3.6v DC
If you don't the most likely culprits are <in order>
D16 <3.6 V 1 Watt Zener>
or D11 & D12 <both 1n4002>
When all is well You should have 3.3v DC at + of C58
And +6.6V DC at + of C48 .
The unit will not work unless the board is screwed back onto the chassis because
the chassis is used as part of the ground-path.

Zim