Please help

[iMAD]

Hi there all members Electro Tech,

I wonder if i can ask for your help regarding an electronic item,

It's a massager chair that had an Adaptor INPUT: 120VAC 60Hz 42W & OUTPUT: 12VDC 2A. I tried to connect this machine to UK Voltage Adaptor INPUT: 230-240V 50Hz OUTPUT 12V 1.67A 20VA. After that the machine stopped working and the Voltage Regulator (LM7805 MX511) was very Hot. So i tried to replace the Regulator with LM7805C & TS7805 but non of them work. I attached a photo of the circiut SORRY NOT VERY CLEAR PHOTO.

I really appreciated your input.

Have a nice holidays

Imad

 

[audioguru]

I think your replacement power supply had an AC output instead of a DC output like the original one, so now most circuitry is fried.

 

[iMAD]

Thanks Audioguru,
Dos that mean it's not repairble ? even if i replace all the component on the circuit ?

 

[Russlk]

The UK adapter is not powerful enough. You need to supply 12 volts at 2 amps, 1.6 amps is not enough. If the adapter was supplying AC, it did not do the circuit any good but it is still repairable. Get the proper adapter and try it again.

 

[iMAD]

Thanks Russlk,
I used UK adaptor only once to see if it's gonna work but the machine start making a funy nois so i quickliy discounct it & never used it again. Right after that i used the original adaptor connected throught my 240V-110V
transformer & it was working fine,(that how i was using befor) but the very next day when i tride to use it again it stoped working & burning smell coming from the volltege regulator.

 

[Russlk]

Try replacing the voltage regulator and the input and output capacitors.

 

[iMAD]

wonderful staff Russlk,

I 'll try & i 'll post back the result

 

[iMAD]

It diddn't work !!

I have replaced the vollteg regulator + two capacitors one was rated at 100uf 25V and other one was 220uf 25V.

I guss i have to give up !

But thanks for the valuable replys, and i really injoyed the challange even though i have failed

Imad

 

[Hero999]

Your chair is probably broken because the adaptor was DC instead of AC.