New RCA Cable->No Sound

[Apoplectic]

Soldered in a new RCA cable in the back of my SL-1900 and now I have no sound. I made sure I soldered them all into the right place. What could I have done to get nothing?

 

[gadget73]

No chance there is a solder bridge from ground to "hot" on the RCA connection is there ?

 

[Duane]

1) Are both channels failing?
2) Was it working before you replaced the wiring?
3) Did you mark or write down where the the two wires for each channel go on the table's connection block?

You will obviously need to do some trouble shooting. Do you have a volt/ohm meter or a digital multimeter?

 

[boreas]

No chance there is a solder bridge from ground to "hot" on the RCA connection is there ?

After checking your work, if you find it okay, test the continuity of the new cables, left and tight, positive and negative. It's not unheard of that new cables are defective.

John

 

[boreas]

Soldered in a new RCA cable in the back of my SL-1900 and now I have no sound. I made sure I soldered them all into the right place. What could I have done to get nothing?

I just noticed that you said that you soldered in the new cables without disassembling the turntable? In other words, did you just solder the new cables to the cut off ends of the old cables? Also, why did you replace the cables? Were you having a problem? If so, what did you do to diagnose the problem?

John

 

[Apoplectic]

1) Are both channels failing?

Yes

2) Was it working before you replaced the wiring?

Yes

3) Did you mark or write down where the the two wires for each channel go on the table's connection block?

No, I took pictures

You will obviously need to do some trouble shooting. Do you have a volt/ohm meter or a digital multimeter?

A multimeter

I just noticed that you said that you soldered in the new cables without disassembling the turntable? In other words, did you just solder the new cables to the cut off ends of the old cables? Also, why did you replace the cables? Were you having a problem? If so, what did you do to diagnose the problem?

John

I took the bottom off. I unsoldered the old ones from the board, and soldered the new ones to it. I did it for not other reason than to try to upgrade it.

No chance there is a solder bridge from ground to "hot" on the RCA connection is there ?

There was on the right channel. I tried to redo it, but I think I ended up burning off that shiny pad thing on the PC board you solder stuff to. Please tell me I'm just imagining this and that's not actually possible, and I didn't just **** my only working tt.

 

[Duane]

A multimeter

Ok...did you use it to check for continuity?

 

[Apoplectic]

Ok...did you use it to check for continuity?

Its continuous, I think I bridged two of the solders.

 

[gadget73]

It is possible to rip solder pads off and crack them. Usually not all that major of a problem though if you're creative and careful. Just follow the trace to wherever it goes to another connection point, and solder your wire onto there.

Also, make sure you've got the headshell or cartridge removed when checking for shorts, otherwise you'll probably read through the cartridge. ALso, don't use the higher voltage continuity checker function through the cartridge. Its vaguely possible that it can burn out the coils. Not really likely but you can never be too careful.

 

[Apoplectic]

I know exactly where the path leads, about an inch away where the tonearm wires end. Would there be any problem with me soldering it to the end of tonearm wires?

 

[shelly_d]

I know exactly where the path leads, about an inch away where the tonearm wires end. Would there be any problem with me soldering it to the end of tonearm wires?

Only if you damage that connection while soldering. It would help us to help you if you took photos and posted them here.

Shelly_D

 

[Apoplectic]

Got Pic If You Want It. (had to be done :yes

 

[boreas]

Got Pic If You Want It. (had to be done :yes

That would be really good with a little barbecue sauce on it!

Can't tell for sure but it looks like the left ground pad is basically gone where the interconnect is supposed to be soldered in. It also looks as if the tonearm wires could be bridged between left signal and left ground and maybe the same for the right channel.

I know you checked for continuity the good way. Did you also check for it the bad way (between signal & ground and between left and right channels)?

John

 

[ebacon]

Damn.

You lifted a pad and trace off the PCB. It will take some finesse to patch that. Electrically it's easy. It's the surgery that takes a steady hand.

 

[shelly_d]

With that much damage to the trace on the left ground, the one that needs to connect to the shield of the interconnect, I would not try to connect the RCA cables directly to the board. I think it would prove to be unreliable in the future, possible tearing the tonearm cable off the pcb as well.

Instead I would take about 6" of a pair of stranded wire, say white and black. Wrap the black wire in a spiral around the white. This creates a twisted pair. On one end solder an RCA Jack (Female) using the black to the outside (shield) and white to the center. Thread the pair through the strain relief on the PCB (that C shaped opening). Place a small blob of epoxy on the side of the PCB and then wrap the free end of the wire around the strain relief laying the wire through the epoxy. Wait for the epoxy to cure and then solder it to the circuit board, black to the negative and white to the positive.

Do this for both channels. Then use interconnects with RCA's on both ends. Use cable ties to secure the turntable end of the interconnects inside the turntable to prevent movement of that end.

That's how I would deal with what you have.

Shelly_D

BTW. I would not use any BBQ sauce on that if I were you. Dry rub it.

Shelly_D

 

[Apoplectic]

Instead I would take about 6" of a pair of stranded wire, say white and black. Wrap the black wire in a spiral around the white. This creates a twisted pair. On one end solder an RCA Jack (Female) using the black to the outside (shield) and white to the center. Thread the pair through the strain relief on the PCB (that C shaped opening). Place a small blob of epoxy on the side of the PCB and then wrap the free end of the wire around the strain relief laying the wire through the epoxy. Wait for the epoxy to cure and then solder it to the circuit board, black to the negative and white to the positive.

Do this for both channels. Then use interconnects with RCA's on both ends. Use cable ties to secure the turntable end of the interconnects inside the turntable to prevent movement of that end.

That's how I would deal with what you have.

Still got nothing.

There looks to be a guy on ebay parting out his SL-1900, I'll send him a message to see if he still has that little board. I'll take it to the pro's to install.

Alternatively I could part it out, sell a few of my amps that I do not use and get either a tt with RCA sockets in the back (which seems to be be the exception of the rule and only on lower end tables) or something with a beefier, non-pc board interconnects. Maybe an old Dual or Garrard?[/whiteflagwaving]

 

[shelly_d]

A little careful trouble shooting will go a long way toward solving this. There are very few things that can go wrong. You have one of these issues: open wires or connections, shorted connections, wiring reversal or blown cartridge. We are going to take it one test at a time:

Looking for Opens:

Using a needle nose pliers, carefully note and remove the wires attached to the cartridge. You want to be able to put them back on the same positions when you are done.

Using your multimeter set to measure ohms or continuity, check to make sure that you have continuity from the cartridge end of the red wire to the circuit board end. Do the same test for each of the others. Then perform the same test from the cartridge end of each wire to the next point in the chain, I assume from your post that it would be the female RCA jacks you soldered in. Each step should show continuity. Make sure you do NOT let any of the wires touch each other during these tests.

Good here is each test shows 0 ohms or good continuity. Any open must be corrected.

Looking for Shorts:

With this test it is again critical that all the wires are removed from the cartridge and not touching each other. At the RCA jacks that you soldered on, you need to do 3 tests. The first is continuity between the center pin of the left to the center pin of the right channel. This must read as open or infinite resistance, no continuity. Each of the next tests are to measure from the center pin of the RCA jack to the outside connector of the RCA jack, looking for continuity. There should not be any, it should be open or infinite resistance. If there is any, you need to correct that.


Checking the interconnects:

If those tests are all good, you need to check the new interconnects that you are using while they are off the turntable. Check each for center pin at one end to center pin at the other end. This should read as having 0 ohms of good continuity. Do the same for the outer connector and you want the same reading. Finally test from the center pin to the outer connector with the cable NOT hooked up to anything. This should read open or infinite resistance. If it fails any of these tests the interconnect either has an open or a short.

Visual confirmation of the wiring:

Check to see that the wiring arrangement you set up is correct. The white tonearm wire must go to the center pin of the left channel RCA jack. The blue wire to the outer connector of the left channel RCA. Verify this with the multimeter it need be.

The red wire goes to the center pin of the Right channel RCA and the green wire to the shield or outer connector of the right RCA.

Do these tests, take a picture of how you have the turntable set up now and post back with the exact details of each of the tests. Don't try to put the turntable back into service yet. We want to go through this very methodically to verify each step and get the fix correct.

Shelly_D

 

[Apoplectic]

A little careful trouble shooting will go a long way toward solving this. There are very few things that can go wrong. You have one of these issues: open wires or connections, shorted connections, wiring reversal or blown cartridge. We are going to take it one test at a time:

Looking for Opens:

Using a needle nose pliers, carefully note and remove the wires attached to the cartridge. You want to be able to put them back on the same positions when you are done.

Using your multimeter set to measure ohms or continuity, check to make sure that you have continuity from the cartridge end of the red wire to the circuit board end. Do the same test for each of the others. Then perform the same test from the cartridge end of each wire to the next point in the chain, I assume from your post that it would be the female RCA jacks you soldered in. Each step should show continuity. Make sure you do NOT let any of the wires touch each other during these tests.

Good here is each test shows 0 ohms or good continuity. Any open must be corrected.
Looking for Shorts:

With this test it is again critical that all the wires are removed from the cartridge and not touching each other. At the RCA jacks that you soldered on, you need to do 3 tests. The first is continuity between the center pin of the left to the center pin of the right channel. This must read as open or infinite resistance, no continuity. Each of the next tests are to measure from the center pin of the RCA jack to the outside connector of the RCA jack, looking for continuity. There should not be any, it should be open or infinite resistance. If there is any, you need to correct that.


Checking the interconnects:

If those tests are all good, you need to check the new interconnects that you are using while they are off the turntable. Check each for center pin at one end to center pin at the other end. This should read as having 0 ohms of good continuity. Do the same for the outer connector and you want the same reading. Finally test from the center pin to the outer connector with the cable NOT hooked up to anything. This should read open or infinite resistance. If it fails any of these tests the interconnect either has an open or a short.

Visual confirmation of the wiring:

Check to see that the wiring arrangement you set up is correct. The white tonearm wire must go to the center pin of the left channel RCA jack. The blue wire to the outer connector of the left channel RCA. Verify this with the multimeter it need be.

The red wire goes to the center pin of the Right channel RCA and the green wire to the shield or outer connector of the right RCA.

Do these tests, take a picture of how you have the turntable set up now and post back with the exact details of each of the tests. Don't try to put the turntable back into service yet. We want to go through this very methodically to verify each step and get the fix correct.

Shelly_D

I didn't quite do what you said. I soldered on the wires (used some speaker wire for this, figured it would be better than general house wire) to the tone arm wire interconnects, wire tied the wires to the C thingy (I don't have epoxy, paid all my bills yesterday and I need to make $10 last till payday), butt ended those wires to the RCA cable I was trying to upgrade it to. I don't have any female RCA disconnects.

I just removed the headshell for this one. Between center pin and center pin reads OL.

And as you expected, the rest of the soldering pad did pop off.

 

[shelly_d]

You need to run the continuity checks I described. Also, the way you have set up the wiring you really don't have a twisted pair there. You want it to look more like this:

 

[Uncle Bambi]

I have a Technics SL-D2 carcass that has pretty much been stripped, but still has the internals. I don't know if the little board inside my parts unit will work for your SL-1900, but you are welcome to it.