Saturday, September 16, 2017

Sayona SHT-1132BT Woofer repair dead now repaired

A few days ago I got a knock at my gate very early in the morning and I wondered what could have necessitated the visit and I almost came out armed.

Upon opening the gate I found one of my neighbor standing there holding a woofer and after excusing himself he told me that he wanted it checked urgently and he suspect it burnt after the power surge though I can’t remember experiencing any in my house.

I took the machine and kept it in my workshop which is within my house and went to work. In the evening I came back and went straight to the woofer and before opening I could smell something burnt inside and after opening this is what I saw.

Yes! The four bridge diodes were burnt beyond recognition.

Before continuing I decided to check if the transformer was gone or not and after dis-connecting it from the board I applied the power and I was able to test all the outputs and were okay and with this I concluded the transformer was okay.

To me this was a big relief since getting the spare for this kind of transformer is not easy in my place.

I decided to replace the four diodes and therefore I removed them carefully and replaced them, since the two fuses were okay I did not suspect any more components shorted.

I then decided to apply the power with the motherboard connected but since I was not sure if there were any other component shorted I decided to use my series lamp current limiter.

After applying the power I noted the bulb remained bright and this means there was still something shorted in the system.

To get the culprit I decided to use the touch method whereby after applying the power via the series bulb for a few minutes dis-connected the power and started touching main suspect component which are prone to shorting like transistors, I.Cs and I after touching one of the amplifier I.C TDA2030A I noted it was very hot for my finger and concluded this must be one of the culprit.

Also keen observation I noted one of its leg was dark meaning it was getting very hot to the point of changing the color as you can see the picture above.

I pulled it out of the circuit and again applied the power and this time the series bulb lite and then went off.

This is a good sign that no more shorted component in there and therefore got a replacement ic TDA2030A which was readily available in my store.

I replaced it and after applying the power I got aloud humming sound from the woofer and I concluded I may have finally got the system working again.
Here is the inside of the woofer

Thank you guys
See you in the next class


  1. Dear Sir,

    Thanks for your useful classes, will you please explain me, How to add the USB port option in old CD player.

  2. My sayona lost the should. What could be the problem.

  3. My sayona transistors are hot and are meassuring a shot .what may be the ploblem ?

  4. My sayona has just went off from functioning and i am told that the problem is the usb/sd port. Where can i get one thats made from sayona repair accessories