[ashy79]

hi... after reading this mx5021 mod guide, I'm so tempted to try it out on my ancient acs45.1 & without much hesitation.. I did... mess it up >.<

the ori caps are
10KµF 25V X 1
1KµF 16V X 2
220µF 16V X 1
100µF 16V X 3

replaced by
pana TSHA:
22KµF 25V
pana FM:
2.2KµF 16V
470µF 16V
330µF 16V

stock opamps are 5 x ST's MC4558CN (googled, they're dual)
all replaced by national's LM4562NA

made sure (I think I did) all the solder points are properly connected... tested with multimeter... near to 0 ohm

after it's all done... when I switch on... the speaker make WOO WOOO noise as if it's in very high volume & the signal is disturbed... I cannot turn it off by pressing both volume buttons (this is how acs45.1's button works), the on/off indicating light is always on.. turn bright & dark everytime the volume button is pressed

I then tried to plug in audio jack & played some songs... nothing came out....

pics will be up in few hours... charging batteries now, any inference to be made based on just these? thanks in advance... any help will be greatly appreciated....

 

[ashy79]

amplifier is TDA7375, data sheet here
22KuF 25V is temporarily removed due to its bulky size...

FRONT:

REAR
before

after

traces that came off were probably contacted back... bad trace 1 was a tad too serious... so I used wire... all points were checked & shown connected though.... the bad trace on opamp actually caused me to spend quite some time on it... do opamp spoil easily due to overheating?... after a soldering move I blow on it to cool it down... though....

stock opamps: (legs aren't in good shape now...)
http://i42.photobucket.com/albums/e3...tockopamp1.jpg
http://i42.photobucket.com/albums/e3...tockopamp2.jpg
http://i42.photobucket.com/albums/e3...tockopamp3.jpg
http://i42.photobucket.com/albums/e3...tockopamp4.jpg
http://i42.photobucket.com/albums/e3...tockopamp5.jpg

miscellaneous (some view on other caps etc on board...)
http://i42.photobucket.com/albums/e3...s451/misc1.jpg
http://i42.photobucket.com/albums/e3...s451/misc2.jpg
http://i42.photobucket.com/albums/e3...s451/misc3.jpg
http://i42.photobucket.com/albums/e3...s451/misc4.jpg
http://i42.photobucket.com/albums/e3...s451/misc5.jpg

seriously need you guys' expertise... please help... would really appreciate it T.T thanks lots again in advance T.T

 

[TzeYang]

sometimes, if it's a two layer board, you cant just simply jumper it to fix it. You have to know whether if there are two set of traces connected to that particular point. I suspect a short or something weird happened when you tried fixing the board.

As for the opamp swap or cap swap, I'm sure they arent the cause of the problem.

EDIT: Have you tried swapping back the old opamp to be 100% sure that those arent the cause of the problem?