Watson AS4541 no power

[budm]

Re: Watson AS4541 no power

The heatsink is not connected to the circuit ground, right? Does the heatsink have the electrical connection the Negative power supply?
It sounds like you have bad connection since it works some time.

[Morsus]

Re: Watson AS4541 no power

Checked the connection between the heatsink and transformer input jack pins - none or the 3. Next I started searching for connections through the board and found out that this branch is actually connected to the heatsink.

Another thing that I noticed is that this one jumper maybe touches a diode it shouldn't so I separated them as best as I could. The result was the same.
I don't know what told me to check the fuse again and I found it with a burn mark on it. Checked it and yup it was broken in one of my previous attempts of testing. I am on my way to the electric shop to buy few more of the same kind.

[Morsus]

Re: Watson AS4541 no power

Okay, I'm back. I told the store workers that I need a 0.25A 250V fuse but they don't have the same exact ones so they gave me 0.65A 220V. The markings on the fuse are M530/250C. Is this really fine?

[madan1]

Re: Watson AS4541 no power

No, it is not fine.
Until you have a working unit you should not experiment with higher gauge fuses.
Even when you are sure that the unit is operating properly you should not use fuses with higher limits than the ones which the manufacturer specified in the documentation.

[budm]

Re: Watson AS4541 no power

The main AC fuse is rated at 0.25A? And it blew the fuse when you did what test?
BTW, so the heatsink is connected to the (-) supply which makes senses since the tab of the IC is for negative supply (-VCC).

[Morsus]

Re: Watson AS4541 no power

I'm not sure,I was measuring a lot xD

[Morsus]

Re: Watson AS4541 no power

I found the exact same fuse. The woofer worked for a whole day. This morning when I started it it wouldn't power on. After opening the case again, disconnected all cables, found two "might be bad" caps. After putting it all together without doing anything else it worked again. And it still works but I guess its just a matter of time for it to stop working again. here are the pics of those two caps, could those be bad? The one has the same orange-brownish goo on and under it, I am guessing its only the secure glue.