Who Can Read a Circuit Board ?

N

Nilesh

Enthusiast
Hi Guys , I have some problem to bypass an onboard transformer to a replacement one . I have bought the replacement transformer but i can't figure out where to solder the Output 12V Red And Black Cable. Anyone can help ??
 
slipperybidness

slipperybidness

Audioholic Warlord
Hi Guys , I have some problem to bypass an onboard transformer to a replacement one . I have bought the replacement transformer but i can't figure out where to solder the Output 12V Red And Black Cable. Anyone can help ??
Pictures are you friend.

Where does the original transformer connect? You are almost certainly gonna need to disconnect the original transformer. Otherwise, the 2nd transformer will be sending its signal back through the secondary turns on the original tf.
 
N

Nilesh

Enthusiast
The Original Transformer Is Soldered On The circuit board itself. I am uploading pictures .....Just 5 minutes .
 
slipperybidness

slipperybidness

Audioholic Warlord
http://i64.tinypic.com/20p3qc6.jpg

Circuit Part
Ignore The Red Red Black Cable. These are mis soldered . Thats Why i am asking if you can tell me where to solder them ??
OK, this may be tough to help remotely.

But, here is my first set of questions:

1) Are you 100% certain that the transformer is faulty? Are you 100% certain that the transformer is the ONLY fault? It is fairly rare to have a transformer die, what are the symptoms that you are experiencing here? Have you checked the fuses for continuity with a continuity meter (don't rely on visual inspection)?

2) Why not completely remove the faulty transformer from the board? that should be maybe a 10 minute task with some fresh solder and a solder sucker. If you don't have this basic skill set, then I really have to advise that perhaps you should not be working on this board solo.

3) Does the transformer on the board output a single voltage or a dual-voltage rail? So, a single voltage will have a common connection line and a power line that will be something like +5V or +12V etc. On the other hand, a dual voltage output will have a common line and something like a +12V ouput AND a -12V output.

4) What voltage is you mains line?

5) Does your replacement transformer have single-tap windings or dual-tap windings? And, this question goes for the primary windings and the secondary windings too.

If any of these questions or terms are over your head and/or confusing to you, then you really need to take a step back and learn these terms, or at least become familiar enough with them to communicate effectively for proper support.
 
N

Nilesh

Enthusiast
Have you got the pictures ? .Its because the system does allow photos.above 1mb . I had to use tinyurl...If you did.not.got it , let me.know
 
slipperybidness

slipperybidness

Audioholic Warlord
Have you got the pictures ? .Its because the system does allow photos.above 1mb . I had to use tinyurl...If you did.not.got it , let me.know
I saw the pics, then asked the questions.
 
N

Nilesh

Enthusiast
OK, this may be tough to help remotely.

But, here is my first set of questions:

1) Are you 100% certain that the transformer is faulty? Are you 100% certain that the transformer is the ONLY fault? It is fairly rare to have a transformer die, what are the symptoms that you are experiencing here? Have you checked the fuses for continuity with a continuity meter (don't rely on visual inspection)?

2) Why not completely remove the faulty transformer from the board? that should be maybe a 10 minute task with some fresh solder and a solder sucker. If you don't have this basic skill set, then I really have to advise that perhaps you should not be working on this board solo.

3) Does the transformer on the board output a single voltage or a dual-voltage rail? So, a single voltage will have a common connection line and a power line that will be something like +5V or +12V etc. On the other hand, a dual voltage output will have a common line and something like a +12V ouput AND a -12V output.

4) What voltage is you mains line?

5) Does your replacement transformer have single-tap windings or dual-tap windings? And, this question goes for the primary windings and the secondary windings too.

If any of these questions or terms are over your head and/or confusing to you, then you really need to take a step back and learn these terms, or at least become familiar enough with them to communicate effectively for proper support.
1) Yes , the transformer on onboard is dead , because before unsoldering it partly i tested the output voltage which gave nothing . Its a 12V AC output .Fuses Onboard Are All Beeping with continuity test .
2) Yeah Sure I can do that ..I can Desolder it Fully .
3) I am.Not Sure Since It got the Soldered On the Board With The Piece Of Metal Strips . How will i identify the wires :( , You seen the photos :(
4) Mains Line Is 220/240V ...
5) Single Tap Windings . See link of.new transformer photo http://i64.tinypic.com/no8rab.jpg
 
N

Nilesh

Enthusiast
What I forgot to tell you that i have already cut off Mains Line To The Circuit Board . I connected The Power Switch Directly To The New Transformer Input .
 
N

Nilesh

Enthusiast
Okay, now i have dismounted the Onboard Transformer . Its out of the circuit board ..Can you help in soldering the replacement one ??
 
slipperybidness

slipperybidness

Audioholic Warlord
Okay, now i have dismounted the Onboard Transformer . Its out of the circuit board ..Can you help in soldering the replacement one ??
So, you say that the old transformer had a 12V AC output. You should be able to see the traces on the PCB where the output of the old transformer were connected, right? Is it just 2 connections on the output to the PCB?

The output (i.e. secondary windings) should be a simple swap to exactly where the old transformer was attached to the PCB. Did you have it hooked up like that before, while the old transformer was still on the board?

If that old transformer was shot, then it may have been shorted in the windings, and hooking up the new transformer without taking out the old one would be a problem if that were the case.
 
slipperybidness

slipperybidness

Audioholic Warlord
OK, this may not be trivial even if the board were sitting in front of me, much less trying to help with pics and a description.

Let's focus on the NEW transformer fist, and the inputs. The Input for a transformer is also called the Primary windings. These windings will be connected directly to the mains line from your wall. In practice, the mains will likely go through a switch and a fuse and then to the transformer. Does that make sense? Can you trace the traces on the PCB to figure out exactly where the old transformer was getting fed from the mains? That is where the new transformer primary windings will connect. Alternatively, you may be able to skip the PCB altogether and wire the primaries directly off the fuse on 1 connection and onto the common on the 2nd connection.
 
slipperybidness

slipperybidness

Audioholic Warlord
Next, let's focus on the Outputs of the NEW transformer, transformer outputs are also called the secondary windings.

So, you only have 2 connections on the secondaries. 1 of those will connect to the common and the other will connect to the +12V where the old transformer was connected.

Were you able to get a part # off of that old transformer? Did the old transformer have multiple taps on the output? That seems to be what you are telling me. If that is the case, the problem may be that the new transformer is not a suitable replacement. Could you find an identical transformer as the old one?
 
slipperybidness

slipperybidness

Audioholic Warlord
http://i64.tinypic.com/20p3qc6.jpg

Circuit Part
Ignore The Red Red Black Cable. These are mis soldered . Thats Why i am asking if you can tell me where to solder them ??
On this pic, I see what I think are 3 connections on that PCB from the old transformer. Are those the outputs (secondary windings)? The connection on the right has a + sign a little further up the trace. Is there a - a little further up the trace for the LEFT connection in that pic? And, perhaps a symbol for ground on that middle connection trace?

EDIT: Now that I zoom and look closer, that + sign that I see may just be polarity markings for diodes, so I may be on the wrong track with the above comments.
 
Bucknekked

Bucknekked

Audioholic Samurai
On this pic, I see what I think are 3 connections on that PCB from the old transformer. Are those the outputs (secondary windings)? The connection on the right has a + sign a little further up the trace. Is there a - a little further up the trace for the LEFT connection in that pic? And, perhaps a symbol for ground on that middle connection trace?

EDIT: Now that I zoom and look closer, that + sign that I see may just be polarity markings for diodes, so I may be on the wrong track with the above comments.
I think we need one of @TLS Guy famous advisory quotes about now.
 
N

Nilesh

Enthusiast
OK, this may not be trivial even if the board were sitting in front of me, much less trying to help with pics and a description.

Let's focus on the NEW transformer fist, and the inputs. The Input for a transformer is also called the Primary windings. These windings will be connected directly to the mains line from your wall. In practice, the mains will likely go through a switch and a fuse and then to the transformer. Does that make sense? Can you trace the traces on the PCB to figure out exactly where the old transformer was getting fed from the mains? That is where the new transformer primary windings will connect. Alternatively, you may be able to skip the PCB altogether and wire the primaries directly off the fuse on 1 connection and onto the common on the 2nd connection.
Yes thats what i did , i connected the transformer primary windings directly off the Main Switch .
 
N

Nilesh

Enthusiast
Next, let's focus on the Outputs of the NEW transformer, transformer outputs are also called the secondary windings.

So, you only have 2 connections on the secondaries. 1 of those will connect to the common and the other will connect to the +12V where the old transformer was connected.

Were you able to get a part # off of that old transformer? Did the old transformer have multiple taps on the output? That seems to be what you are telling me. If that is the case, the problem may be that the new transformer is not a suitable replacement. Could you find an identical transformer as the old one?
No , its difficult to get these type of transformer .The ones that get soldered directly onboard :/ .
Yes , the old transformer had multiple taps on the outputs .
 

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