Boss PH-2 Phaser - Low output

[nikooO_o]

I have some problems with my Boss PH-2 Phaser pedal.
When active, the output volume drops to a level where the sound can barely be heard. Adjusting the rate/depth/res/mode knobs still changes the sound as expected.
Below are the results of measurements done while the pedal was running on battery power.
Any help would be appreciated.


The schematic: http://img.photobucket.com/albums/v474/mhammer/PH-2_2.png
D5 and R9 are removed and replaced by a jumper, for the pedal to be powered by a 9v regulated PSU.

The following measurements were made
Q1
S 4,85 V
G 3,70 V
D 8,18 V

Q2
S 4,08
G -0,09
D 4,09

Q3
S 4,10
G 0,12
D 4,10

Q4
B 0,59
C 0,01
E 0

Q5
B 0,61
C 0,03
E 0

IC1 M5218AL
1 4,08
2 4,08
3 4,07
4 0
5 4,08
6 4,08
7 4,08
8 8,16

IC2 NE570N

1  0,99
2  1,81
3  1,81
4  0
5  1,80
6  1,80
7  3,01
8  1,80
9  1,80
10 4,64
11 1,81
12 1,80
13 8,15
14 1,85
15 1,81
16 1,13

IC3 IR9022

1 4,08
2 4,08
3 4,07
4 0
5 4,07
6 4,07
7 4,07
8 8,15

IC4 IR3109

1  5,46
2  5,46
3  2,54
4  5,45
5  5,47
6  2,57
7  5,50
8  0
9  5,43
10 5,46
11 2,55
12 5,45
13 5,46
14 2,57
15 5,50
16 8,10

IC5 IR9022

1 4,04
2 4,05
3 4,05
4 0
5 4,05
6 4,05
7 4,05
8 8,11

IC6 IR9022

1 4,04
2 4,04
3 4,03
4 0
5 4,04
6 4,04
7 4,04
8 8,08

IC7 IR3109

1  5,44
2  5,44
3  2,59
4  5,41
5  5,45
6  2,65
7  5,50
8  0
9  5,41
10 5,44
11 2,56
12 5,38
13 5,44
14 2,67
15 5,52
16 8,07

IC8 IR9022

1 0,64 or 7,43
2 3,90 - 4,15
3 1,4 - 6,7
4 0
5 3,97 - 4,18
6 3,97 - 4,19
7 1,6 - 6,5
8 8,06

IC9 HD14053BP

1  4,03
2  4,03
3  4,02
4  4,03
5  4,03
6  0
7  0
8  0
9  0
10 0
11 0
12 4,03
13 4,02
14 4,02
15 4,02
16 8,05

IC10 IR9022

1 4,03
2 4,03
3 4,03
4 0
5 4,03
6 4,03
7 4,03
8 8,07

D1

A 0
K 8,06

D2

A -0,23
K 0,03

D3

A 0,06
K 4,88

D4

A 0,03
K 5,45