JBL Creature, pc/ipod 3.5mm stereo, line level input, amp/wo

[N_Cook]

How to get inside the casing?
8 screws under removed and I've got a plectrum between the 2 main case
parts and can see presumably fixing catches but soon I'll be splitting
the case, rather than it coming apart. What looks like hidden fixings
under the label are moulding injection/blow-hole marks.
Very low level sound on all 3 speakers is the problem once I get inside it.

 

[N_Cook]

On 18/06/2014 20:39, N_Cook wrote:

How to get inside the casing?
8 screws under removed and I've got a plectrum between the 2 main case
parts and can see presumably fixing catches but soon I'll be splitting
the case, rather than it coming apart. What looks like hidden fixings
under the label are moulding injection/blow-hole marks.
Very low level sound on all 3 speakers is the problem once I get inside it.

Initial separation point along a side , not under the logo , that I
decided on. Internal corner posts seem to be the holding points,
screwdriver blade at those points and prize apart.
Full metal, not matalised plastic knobs, are glued to the pot shafts,
small blade digging into the metal at the lowest point in the casing
hollow and twisting against the plastic case, forces them off.
2004 is the date , will work on the electronics tomorrow

 

[N_Cook]

Must be mark 1 version, not recent 3.
0.1V 400Hz on combined pins 9&16 of the TDA8512J produces 1.7V over 4R
speaker so that presumably is ok.
Twizzle sticking elicited nothing.
+4V and 26.6V DC rails looks a bit odd but only one main cap, maybe the
4V should be 9V or so
Then to find what the Q12 N448AB transistor does, also on the heatsink.
Why some digital chips in there?
This funny bell shaped thing was working, put on an indoor shelf for a
few years and then next to nothing when brought out of retirement.

 

[N_Cook]

main caps ESR'd ok. The 4V dc is probably mains ac sampling for some
compensation purpose. What is the 4011,4013 and a couple of other 14 pin
digital devices for?

 

[N_Cook]

Looks as though a case of forgetfulness and RTFM.
Put aside as one satellite had failed, forgotten about, notorious
problem with these , glue fails and the speaker magnet is pulled to the
front by the suspension and then cone movement is bottomed out, so just
amechanical problem, plus bad ESR cap inside the orange satellite at
some point.
The digital is for the vol control , that is stored NV, and still set as
low years later. Control is via 2 little buttons on the "orange" failed
satellite. Bass and treble pots on the main unit