Identifying Part from Schematic

[paulstef]

Re: Identifying Part from Schematic

The primary windings on transformer all have resistance with one another.

Would it be possible to use two seperate transformers? I have plenty of room and can mount another inside chassis.

Just out of curiosity, what resistance do you measure? And what fuse did you use?

I'd say it's not impossible to use separate transformers, you'd need to find the right wattage...

[mikay786]

Re: Identifying Part from Schematic

Have done, on the AC socket it's 0.L on all points. On voltage selector is 0.L on points, aside from 2 which depending on position of switch, so that seems fine.

The primary windings on transformer all have resistance with one another.

Any idea on a replacement transformer? I'm guessing it's difficult due to dual different output voltages, 55ac and 12vc?

Would it be possible to use two seperate transformers? I have plenty of room and can mount another inside chassis.

[budm]

Re: Identifying Part from Schematic

If you disconnect the primary winding from the circuit and then check the resistance between the terminals where the primary winding wires of the transformer were connected to, the resistance should show infinite resistance, but more likely you have bad transformer with shorted turn.

[stj]

Re: Identifying Part from Schematic

good, based on statistics the rest of us wont see one for a year!

[mikay786]

Re: Identifying Part from Schematic

I would probably disconnect the transformer completely and measure resistance of primary first before continuing to blow up fuses...

But from what you describe it really seems to be your transformer. I think I never had a faulty low frequency transformer

This is my 2nd in a month!

[mikay786]

Re: Identifying Part from Schematic

you could just put a 200v 25a rectifier in knowing it's over-rated.
got a foto of the one you have for size comparison?

btw, shit design - it needs a couple of fuses on the outputs from the rectifier or caps.
as it is, if you have a shorted output transistor it will overload everything until the mains fuse blows - or something else does!

I put in a 400v 25a rectifier, then found out I have a dead transformer. Lesson is always test transformer before worrying about and spending money on things further down the line.

[mikay786]

Re: Identifying Part from Schematic

Yep disconnected output side so just transformer on its own

[paulstef]

Re: Identifying Part from Schematic

you could just put a 200v 25a rectifier in knowing it's over-rated.
got a foto of the one you have for size comparison?

btw, shit design - it needs a couple of fuses on the outputs from the rectifier or caps.
as it is, if you have a shorted output transistor it will overload everything until the mains fuse blows - or something else does!

I thought he had the secondary disconnected from the board...

[stj]

Re: Identifying Part from Schematic

you could just put a 200v 25a rectifier in knowing it's over-rated.
got a foto of the one you have for size comparison?

btw, shit design - it needs a couple of fuses on the outputs from the rectifier or caps.
as it is, if you have a shorted output transistor it will overload everything until the mains fuse blows - or something else does!

[paulstef]

Re: Identifying Part from Schematic

tested the filter caps and they seem fine, kinda of torn the transformer apart now !! well just the outer layers to see if there was a short up top.

Well another lesson for the future, ill see if I can put it back together later and tried without connecting to switch. Erm would I just wire directly to the socket bypassing the voltage selector?

I would probably disconnect the transformer completely and measure resistance of primary first before continuing to blow up fuses...

But from what you describe it really seems to be your transformer. I think I never had a faulty low frequency transformer

[mikay786]

Re: Identifying Part from Schematic

tested the filter caps and they seem fine, kinda of torn the transformer apart now !! well just the outer layers to see if there was a short up top.

Well another lesson for the future, ill see if I can put it back together later and tried without connecting to switch. Erm would I just wire directly to the socket bypassing the voltage selector?

[paulstef]

Re: Identifying Part from Schematic

No, I didn't. You mean the film caps and the ac selector?

Yes, just to make sure...

[mikay786]

Re: Identifying Part from Schematic

No, I didn't. You mean the film caps and the ac selector?

[paulstef]

Re: Identifying Part from Schematic

Just to make sure, you tested the primary side also disconnected , right? There is still a switch and a capacitor on the primary side which could be at fault.

[mikay786]

Re: Identifying Part from Schematic

are there any less powerful options if this original is too hard to replace?

[mikay786]

Re: Identifying Part from Schematic

I don't think that's the problem as is blowing fuses, just done a continuity test and all the primary cables have continuity between them!

[budm]

Re: Identifying Part from Schematic

That is the thermal protection device in case the transformer winding gets so hot that it may catch on fire, this device will cutoff the power to the transformer winding. That device should show <1 Ohms between the two leads.

[mikay786]

Re: Identifying Part from Schematic

What is this, inside the primary side

says

17 AM
033A5

[mikay786]

Re: Identifying Part from Schematic

I got it from avforums, someone posted it up on there. Not been able to find anything else.

[mikay786]

Re: Identifying Part from Schematic

There's nothing on it apart from sticker saying 185230533, lucky it has markings on the board or would have absolutely nothing to go on.

I feel this is going to be difficult!