Can you test a silicone rectifier with a MM?

[budm]

Re: Can you test a silicone rectifier with a MM?

2.103 'M' Ohms? That is 2.1 Millions OHMS., no it is not shorted.

[mikay786]

Re: Can you test a silicone rectifier with a MM?

So how come on the irfp9240 its was only 0.511m ohm and this irfp240 its 2.103m ohm. Quite a difference.

Anyhow some snaps of the board and readings from the irfp240. The polarity on this one is the opposite of the other, is that normal?

Sub is blowing the external T2a fuse. Internal fuses are ok (They are encapsulated T3.15a fuses)

The silicone rectifier measures ok and only one way in diode mode @

0.48v
0.48v
0.5v
0.48v

[budm]

Re: Can you test a silicone rectifier with a MM?

So how do the rectifiers get the AC from? A power transformer somewhere we are not seeing in the pictures?
Make and model of this sub?

[mikay786]

Re: Can you test a silicone rectifier with a MM?

Yes a transformer

Model is a REL Quake (100w mosfet)

[budm]

Re: Can you test a silicone rectifier with a MM?

Did you use time-delayed type fuse for the main fuse?
Does the main fuse blow if the secondary of the transformer is not connected to the rectifier?
The TOROID transformer has very high inrush current when power is first applied to the transformer winding.

[mikay786]

Re: Can you test a silicone rectifier with a MM?

Yea I only had T3a glass fuse which I pulled out of another sub and it blew that. Its the fuse at the back of the sub.

The fuse in the AC cord is ok.

Erm ive not tested with the transformer disconnected yet. Which colours are the secondary (All of them connecting to the main board). Theres yellow, grey, blue and red going into the main board.

[mikay786]

Re: Can you test a silicone rectifier with a MM?

Speakers hasn't been connected

[mikay786]

Re: Can you test a silicone rectifier with a MM?

Can hot glue cause a short? Large sections of the board was covered in hot glue which I have removed, but tested with glue on.

[stj]

Re: Can you test a silicone rectifier with a MM?

no.

try running it through a light-bulb to limit the inrush.

[mikay786]

Re: Can you test a silicone rectifier with a MM?

Yes T3a fuse just blew only connected to transformer, so transformer is bad? No wires connected to mainboard.

Somebody has already been inside this sub, I'm wondering if this is wired correctly. UK 3 pin socket

Rectangle is fuse. Top of triangle is top pin.

[stj]

Re: Can you test a silicone rectifier with a MM?

no earth connection!!

[mikay786]

Re: Can you test a silicone rectifier with a MM?

TTO-10717-02 transformer

2x33v
1.21a

[mikay786]

Re: Can you test a silicone rectifier with a MM?

There's no other cables inside, just two orange cables.

[budm]

Re: Can you test a silicone rectifier with a MM?

So there are two orange wires on the transformer then?
What is that big black blob on the top left with black cable tie on it?
https://www.badcaps.net/forum/attach...2&d=1448240886
You can probably get other transformer to replace it.
Do you have any scraped linear power supply?

[mikay786]

Re: Can you test a silicone rectifier with a MM?

2 in and 4 out to the board. The black blob is just a cover that goes over the terminal.

Stj mentioned no Earth on the AC in the terminal, but that only has 2 wires going out of it into the transformer.

[mikay786]

Re: Can you test a silicone rectifier with a MM?

To earth would I just make a connection from the ground/earth pin on the terminal to say the bolt next to it making contact with the chassis?

[budm]

Re: Can you test a silicone rectifier with a MM?

To earth would I just make a connection from the ground/earth pin on the terminal to say the bolt next to it making contact with the chassis?

Earth pin of the AC Inlet to the chassis.
So now you need to get new transformer.
The two wires on the transformer are the primary winding of the power transformer.

[mikay786]

Re: Can you test a silicone rectifier with a MM?

Is it possible to repair transformer?

I don't think it will be possible to get a replacement?

[stj]

Re: Can you test a silicone rectifier with a MM?

if there is insulation breakdown near the end you may be able to do something.

can you get any meter readings between the primary winding and any of the outputs?
(i hope not)

[budm]

Re: Can you test a silicone rectifier with a MM?

Is it possible to repair transformer?

I don't think it will be possible to get a replacement?

No, the replacement does not have to be TOROID type transformer, anything from 25-0-25 to 30-0-30 with 1.5A or more will work.