國產合併AMP改機求救

手痕將部國產石amp2隻交連電容由4.7u 50v (non-polar)換造10u 400v (MKP), 之後完全冇聲。
請問是否u 數過大？ (底板上是寫住10u 100v)

Simple check the following step by step

1) did you unplug some cable ? i.e. Input source
2) did you destroy the solder pad when disassemble the old capacitor ?
3) Any dry soldering?
4) What kind of soldering gun you are using? May be your soldering gun have higher ESD to destroy the 2'nd stage amp.

KK



[quote:79e8c45aa6="iamstephen"]手痕將部國產石amp2隻交連電容由4.7u 50v (non-polar)換造10u 400v (MKP), 之後完全冇聲。
請問是否u 數過大？ (底板上是寫住10u 100v)[/quote]

kk sir,

Pls help me too!
lastnight my CDP suddenly stop playing halfway i play a cd, display show "no disc". try press play several time and try eject and play and try other CD still the same. checking all cable connection ok. so suspect is the cap (470uF/35v) show in picture cause teh problem because last 2 day i change this cap & incidently damage the solder pad so i just use solder to connect the2 copper strip on the circuit board and no problem for the last 2 day.

after trying many time last night still same problem display show no0. disc then i remove and reconnect all the cable and redo the soldering on the cap...thing get worse..the whole display dark, no light/word at all. But the power led, cd tray movement, tube supply all ok.
May i know what the function of that blue cap (470uF/35v in green circle)?? will it cause problem on the CD head read & movement?

Really need your advice/help!! thank you!!

Hi KK,

Thank you for your guidance.
I have found one solder pad did fell off from the PCB.
How can I fix this?

Besides, I am using the Goot solder gun (30/60w switchable), I use 60w most of the time.


Stephen

[quote:6d477c8ced="iamstephen"]Hi KK,

Thank you for your guidance.
I have found one solder pad did fell off from the PCB.
How can I fix this?

Besides, I am using the Goot solder gun (30/60w switchable), I use 60w most of the time.


Stephen[/quote]

Dear Kk sir,

I wish to know a better way/proper way on this also. Since if this happen i normally use another cable to bypass the the circuit board and connect to the component where the off solder pad suppose to connect to.

I have checked all contact points and fixed the loosen ones but still there is no sound. Will bring it to audio shop nearby to fix it.

全是英文,晕啊!

谈兄别晕 :

stephen说他检查了线路和交接点都没问题所以要拿去给他人修理。。。

而我的CDP问题暂时解决了，可能是换了些电容导致进入机头(LASER HEAD)的Voltage变了，又或是机头不太好了。 在机头后的调整器作了些调整后就运作如常了！

Since I have free time lately, will try to fix it by myself.
KK told me may be the 2nd stage amp is dead.
Does any body knows are they the 3-leg transistors or the large one binded to heatsinks?

Do I need to wear anti-static waistband to do the soldering this time?

Thanks in advance.