Post by NPAudio on Sept 30, 2022 15:49:30 GMT
vinek
Here's the pictures of your repaired WM1A and modification.
I ended up having to use a psuedo single ended derived from the balanced amp as the single ended is damaged on the s-master (higly distorted) components were tested/replaced and damaged pads repaired.
Balanced out damaged pads were also repaired and I took no chances by using plenty of liquid tape 😅
Unfortunately I don't have before pics but here's a brief rundown, it took me much longer than I anticipated.
Here's the pictures of your repaired WM1A and modification.
I ended up having to use a psuedo single ended derived from the balanced amp as the single ended is damaged on the s-master (higly distorted) components were tested/replaced and damaged pads repaired.
Balanced out damaged pads were also repaired and I took no chances by using plenty of liquid tape 😅
Unfortunately I don't have before pics but here's a brief rundown, it took me much longer than I anticipated.
Removing Audio Note caps
Solder cleanup from cap legs
Straightening of cap legs
Testing of caps uf, esr and voltage leakage.
Some didn't measure well and were binned.
Some became none stable at operating temperature so had to be removed again and binned.
Some became none stable at operating temperature so had to be removed again and binned.
Recut, sand, clean and check for shorts on board cuts.
Thoroughly clean flux and all the solder balls from the circuit board.
Re-wet/clean all solder pads.
Re-wet/clean all solder pads.
Repair missing / damaged solder pads under microscope.
Cut the chassis centre prong back more and lower also plus the two raised areas on the back.
Thoroughly clean all solder balls and aluminium cuttings from in the chassis, and button circuits.
Some solder balls were melted into top plastic so covered this in liquid tape.
Removed the top right screen bubble in the screen loca glue.
Aluminium black dyed all the scratched areas of the chassis.
Reinstall remaining caps plus some new ones.
Install extra super cap.
Cut copper ground plate to accomodate extra supercap.
Install ground wire
Install battery thermistor bypass resistor
Single ended was distorted on both channels after repairing pads and re-replaceing audionotes for poscaps and testing all other components, the signal coming from the s-master was not the same as a working one so s-master must be damaged (over heated) from shorts. I've seen this happen on the balanced side of the s-master before.
A single ended derived from the balanced amp was used instead.
A single ended derived from the balanced amp was used instead.
, I always love seeing his (porn)