Cornet 2 Transformer Switch Hookup

Quicksilverproac · « **on:** 13 Jan 2012, 03:01 pm »

Its built ...and I even mastered the chassie work. I am at the end and I have been unable to hook up the transformer /switch. I have gone over it many times. I see line & l and s & switch.....Does someone have a clear photo or instructions. It seems simple ...but for me its not.

poty · « **Reply #1 on:** 14 Jan 2012, 10:14 am »

I think pages 9-10 describes the process in great details (including some pictures). Actual wiring would depends on outlet voltage.
For example, for 110V:
Blue, Brown/yellow, Black and White/black wires of the transformer would go to the terminals on PCB marked "0"
Blue/Yellow and Black/Red - to "L"
Brown and White - to "N"
All other wires should go to terminals of their own colors marked next to them.
The rest is according to the description.

Quicksilverproac · « **Reply #2 on:** 14 Jan 2012, 08:14 pm »

I am sure I have the transformer & switch hooked up right. However...I am blowing fuses. When I put the meter on L & N it beeps....dead short I think. Could I have a bad transformer? I went over every thing and all looks good. Have these transformers every been a problem? I am not sure how to proceed. Thanks, Allan

poty · « **Reply #3 on:** 15 Jan 2012, 12:50 pm »

First of all - don't panic!

Really - it can be anything!
You have a meter (I hope you use it while your Cornet is not connected to the mains outlet and in resistance position). Lets begin to test!
Earth lug of IEC socket should go to chassis only - so it shouldn't show any resistance (open circuit) to either L or N lugs.
Disconnect all wires from the transformer to the PCB. Try to test the connectivity of the L and N lugs of IEC socket to LINE and NEUTRAL connectors of the PCB. The L to LINE connectivity should be switched by the power switch of the IEC socket. If your Cornet behave in different way - there must be some mistakes in wiring the IEC socket, switch and the PCB.
There should be NO connectivity between L and N. If the connectivity exists - there are mistakes in wiring or probably broken C100.
Connect Blue, Blue/Yellow, Brown, Black, Black/Red, White/Black, White wires to the PCB (according to the outlet voltage chart). Isolate the ends of 2 Reds, Red/Yellow, 2 Yellows, Yellow/Black, 2 Greens, Green/Yellow wires. Do not connect them together!!! Power on the unit. All should be OK. If it is so - the problem is not in the wiring or in the transformer - the problem is in soldering parts or probably bad parts. I'd recommend (after switching off the unit from the outlet!) to try to connect Yellow - Yellow/Black - Yellow wires first (power on - power off), then add Green - Green/Yellow - Green wires (power on - power off), then Red - Red/Yellow - Red (power on - power off). The blowing fuse at each step should indicate what circuit is the problem.

Quicksilverproac · « **Reply #4 on:** 15 Jan 2012, 05:09 pm »

The PCB checks out ...it appears there are no shorts. I connected the primary wires as you said and the fuse pops....It appears there is a short in the transformer. Is this fixable? Thanks very for your help. Allan

poty · « **Reply #5 on:** 15 Jan 2012, 08:45 pm »

What voltage is in your outlet? What wires of primaries do you connect to what terminals?

Quicksilverproac · « **Reply #6 on:** 15 Jan 2012, 08:59 pm »

120...I followed the 120 on the pcb...

Quicksilverproac · « **Reply #7 on:** 15 Jan 2012, 09:00 pm »

I did check the transformer...and it seems ok..?

poty · « **Reply #8 on:** 16 Jan 2012, 07:34 am »

If you test the transformer, the PCB - to - IEC socket wiring is correct, the only things I can think of are:
- solder bridge somewhere between "L" and "0" or "N" and "0"
After pulling out all transformer wires from PCB try to test if there is connectivity between L's, N's and 0's. There should'nt be any! More than than there should'nt be any connectivity between 0's themselves.
- mistake in connection of the transformer
Isolate Blu/Yellow, Brown/Yellow, Black/Yellow, White/Black, Black, White ends from the transformer.
1. Connect only 2 wires from the transformer: Blue to L and Brown ro N. Try to power on the device.
2. If all is OK - power off, add Black to L, White to N, power on.
3. If all is OK - power off, connect Blu/Yellow, Brown/Yellow, Black/Yellow, White/Black, Black, White to different 0's, power on.

If something wrong detected on the step 1 I think you should try to deinstall the transformer and connect a plug, switch, fuse, transformer wires Blue and Brown in serial (to be shure all connections are right) on a clear surface. If fuse blows anyway - the transformer should be replaced. I don't think you can do anything with it.
The step 2 should not reveal anything. If it is so - there are some mistake with wiring (agree - sounds dull, but we are all - humans with complex thoughts

) or some short-circuitings on PCB.
If the problem appears on step 3 - it definitely points to short-circuiting on the PCB.

Quicksilverproac · « **Reply #9 on:** 16 Jan 2012, 02:44 pm »

The yellow /red lug on the pcb shows connectivity to ground. Is that correct?

poty · « **Reply #10 on:** 16 Jan 2012, 02:52 pm »

If you mean R/Y marked lug - yes it should go to ground. But at the stage you (I think) not connect anything from the seconds of the transformer? Then we should find something near primary.

Quicksilverproac · « **Reply #11 on:** 16 Jan 2012, 03:10 pm »

I just blew the fuse with the transformer blue and brown ...in the wall outlet....

poty · « **Reply #12 on:** 16 Jan 2012, 03:27 pm »

If the test was clear (only one coil was connected directly to outlet through a fuse, all other wires are free - not connected together and to anything else) than the only problem left is transformer itself.

Quicksilverproac · « **Reply #13 on:** 16 Jan 2012, 03:35 pm »

Yes....I think its a bad transformer. Thank You Very Much. Allan

poty · « **Reply #14 on:** 16 Jan 2012, 07:41 pm »

I think you should try to give the transformer good visual check: broken wires, if the cover cut into the wires' isolation, maybe some signs of burns, smell...
Then you should be shure if the wires is not short-circuited to the iron.
Try to measure resistance between wires. It should be like:
WHT – BLK =   18.227 Ohm +/-20%
BRN – BLU =   19.586 Ohm +/-20%
RED – RED =   434.813 Ohm +/-20%
YEL – YEL =   0.163 Ohm +/-20%
GRN – GRN =   0.136 Ohm +/-20%
If a value is significantly different you can look at the wires more thorougly.
I hope you will be able to send the transformer back and replace it with good one.

Oh, forgot one more thing - are you sure you use the fuses with right current capability?

Quicksilverproac · « **Reply #15 on:** 19 Jan 2012, 03:06 pm »

1 1/2 amp....I will try it with one amp. I was turning it up with a Variac...could that be a problem. Thanks, Allan

poty · « **Reply #16 on:** 19 Jan 2012, 08:43 pm »

Should be slow blow version. If you use variac the version is not so important, but I then worry about the resulting voltage you used (I mean - to what voltage you stop rising voltage).

Quicksilverproac · « **Reply #17 on:** 20 Jan 2012, 04:09 pm »

I installed a new transformer.....now it works. It was full of hums... worked on both sides. I tracked down the hums with going over all the grounds. However now it only works on one side. The one side sound perfect! If it worked once it should be work now. anyway thanks again for all your help.

poty · « **Reply #18 on:** 21 Jan 2012, 12:14 pm »

Quote from: Quicksilverproac on 20 Jan 2012, 04:09 pm

I tracked down the hums with going over all the grounds.

What could this mean? What you've done exactly!

Quicksilverproac · « **Reply #19 on:** 21 Jan 2012, 09:30 pm »

Only the right side is working. I went over everything...redid the RCA's, looked for cold solder,& shorts & checked the interconnects. Still no left side.