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Laurie
Double Platinum Member
Canada
4854 Posts |
 Posted - 06/30/2009 : 17:59:24
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quote:
Originally posted by jcsifu
I put power supply to the pedal, attached a guitar to input and strummed while probing again. I now have a buzz (similar to touching a live guitar chord while the amp is on)that is audable as I touch the emmiters of both Q1 and Q2.
So, strumming and no signal on the emitter of Q1 makes Q1 a suspect. To confirm all is well with your probing technique, probe the input jack hot lug and ensure you can hear the strumming signal.
If your probing technique is confirmed OK, and you don't have an equivalent replacement for Q1, the easiest way to check Q1 is to pull Q2 and put it in place of Q1 (I recall that they are the same part? take a look at the part number before doing it). Leave the Q2 space in the board empty and try the test again. If you get signal on the emitter of Q1 (the device formerly Q2) then it tells us Q1 is dead. If there is no signal on the emitter of Q1 then the problem is upstream of Q1. Probe for the signal on the components back from Q1 to the input and find out where it stops.
PS: about the help? No problem. |
Edited by - Laurie on 06/30/2009 18:02:27 |
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jcsifu
Copper Member
USA
47 Posts |
Posted - 07/01/2009 : 03:57:53
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quote:
Originally posted by Laurie
quote:
Originally posted by jcsifu
I put power supply to the pedal, attached a guitar to input and strummed while probing again. I now have a buzz (similar to touching a live guitar chord while the amp is on)that is audable as I touch the emmiters of both Q1 and Q2.
So, strumming and no signal on the emitter of Q1 makes Q1 a suspect. To confirm all is well with your probing technique, probe the input jack hot lug and ensure you can hear the strumming signal.
If your probing technique is confirmed OK, and you don't have an equivalent replacement for Q1, the easiest way to check Q1 is to pull Q2 and put it in place of Q1 (I recall that they are the same part? take a look at the part number before doing it). Leave the Q2 space in the board empty and try the test again. If you get signal on the emitter of Q1 (the device formerly Q2) then it tells us Q1 is dead. If there is no signal on the emitter of Q1 then the problem is upstream of Q1. Probe for the signal on the components back from Q1 to the input and find out where it stops.
PS: about the help? No problem.
Ok, so I do get guitar sound out of probing the hot input jack lead, but still no sound from Q1. Q1 is a C1815 npn exipital in my unit. I have on hand 2n5089, bs170, 2n7000, and j201. So I searched for specs sheets to see if they would be able to be substituted. I cannot make any sense of the info looking at the spec sheets, I quite frankly don't know what I am looking for. Would any of the ones I have work? What info out of the specs would I compare to find a substitute? |
Edited by - jcsifu on 07/01/2009 04:03:12 |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 07/01/2009 : 04:46:58
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quote:
Originally posted by jcsifu
Ok, so I do get guitar sound out of probing the hot input jack lead, but still no sound from Q1. Q1 is a C1815 npn exipital in my unit. I have on hand 2n5089, bs170, 2n7000, and j201. So I searched for specs sheets to see if they would be able to be substituted. I cannot make any sense of the info looking at the spec sheets, I quite frankly don't know what I am looking for. Would any of the ones I have work? What info out of the specs would I compare to find a substitute?
Did you probe the base of Q1? No point changing Q1 if there is no sound on the base - if that is the case, something upstream has failed.
IF there is no sound on the base, the 2n5089 is the only transistor in the list that could be used to replace Q1 - all the rest are FETs or MOSFETS. Almost any good quality small signal NPN will work for Q1. The 2N5089 will be fine.
Note though that the pins are different! You will need to be a bit creative. Best thing is to download the data sheets for the 2SC1815 and the 2N5089 and figure out which pin goes in which hole. It can be a confusing process, but don't give up...
To get the datasheets just google "2SC1815 data" and you'll get some hits. |
Edited by - Laurie on 07/01/2009 04:47:31 |
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jcsifu
Copper Member
USA
47 Posts |
Posted - 07/01/2009 : 05:05:58
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quote:
Originally posted by Laurie
quote:
Originally posted by jcsifu
Ok, so I do get guitar sound out of probing the hot input jack lead, but still no sound from Q1. Q1 is a C1815 npn exipital in my unit. I have on hand 2n5089, bs170, 2n7000, and j201. So I searched for specs sheets to see if they would be able to be substituted. I cannot make any sense of the info looking at the spec sheets, I quite frankly don't know what I am looking for. Would any of the ones I have work? What info out of the specs would I compare to find a substitute?
Did you probe the base of Q1? No point changing Q1 if there is no sound on the base - if that is the case, something upstream has failed.
IF there is no sound on the base, the 2n5089 is the only transistor in the list that could be used to replace Q1 - all the rest are FETs or MOSFETS. Almost any good quality small signal NPN will work for Q1. The 2N5089 will be fine.
Note though that the pins are different! You will need to be a bit creative. Best thing is to download the data sheets for the 2SC1815 and the 2N5089 and figure out which pin goes in which hole. It can be a confusing process, but don't give up...
To get the datasheets just google "2SC1815 data" and you'll get some hits.
Got the datasheet already as mentioned before, and it's easy enough to find the pinout. I'll put a 2N5089 in for Q1 and just use some stripped wire insulation to put around the leads so I will be able to switch the base and collectors of the two with out risk of touching. Going to go heat up the iron now... |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 07/01/2009 : 05:15:16
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| Oppppsss... I mispoke! Only change Q1 if you HAVE sound on the base but not the emitter. |
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jcsifu
Copper Member
USA
47 Posts |
Posted - 07/01/2009 : 05:25:42
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quote:
Originally posted by Laurie
Oppppsss... I mispoke! Only change Q1 if you HAVE sound on the base but not the emitter.
I knew what you meant. So I just ripped my best SRV licks and the pedal lives on to fight another stage show. YOU....my brotha....ABSOLUTELY RULE!!! Thank you for the lesson. I did a little searching and came up with sound stethescope and other examples of this type of probing set up, so I will spend time now learning more about aplying this troubleshooting lesson to other parts of the pedal. Should be the same basic idea of follow the signal path, right?
I will now have a celebratory glass of wine, stand in front of my amp pressing mt guitar over my head violently, then and jam my resurected pedal in glory.
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 07/01/2009 : 05:41:21
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Nice! Glad it turned out OK 
Yes to the probing of the signal path. There will be parts of the signal path in some pedals where the probing will upset the circuit. Ideally, the best thing to probe with is an oscilloscope, but doing it with an audio probe will work most of the time. Afterall, it's what your ears hear, not what the trace on the scope looks like that matters. |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 07/01/2009 : 09:28:40
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Hi jcsifu (John)
Welcome to the forum from Australia.
Nice to hear that you & Laurie sorted out your TS9. 
If you check the previous page, I have added the Display HTML for your uploaded pics.
I did not display the 731K sized file as it's pretty big.
Regards Dr. Bob |
Edited by - Dr. Bob on 07/01/2009 09:30:01 |
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jcsifu
Copper Member
USA
47 Posts |
Posted - 07/01/2009 : 09:35:27
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quote:
Originally posted by Dr. Bob
Hi jcsifu (John)
Welcome to the forum from Australia.
Nice to hear that you & Laurie sorted out your TS9.
If you check the previous page, I have added the Display HTML for your uploaded pics.
I did not display the 731K sized file as it's pretty big.
Regards Dr. Bob
Thanks Dr. Bob! I am attaching a smaller size pic...I had to get the hang of preparing a pic for posting. Straight from my camera they are huge files.
Download Attachment:  DSC00175.jpg
86.68�KB
uploaded/jcsifu/DSC00175.jpg
Hi jcsifu - Very close - Just click the edit icon (Pencil on Paper) to see the code below - Moderator
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Edited by - Dr. Bob on 07/01/2009 17:08:06 |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 07/01/2009 : 09:55:06
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Hi jcsifu
For practice, I'll let you add the code on the previous post.
Regards Dr. Bob |
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jcsifu
Copper Member
USA
47 Posts |
Posted - 07/01/2009 : 17:23:04
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So you are saying that I need to post this info
just substitue any new file name for the DSC00175 that is in this post?
jc |
Edited by - Dr. Bob on 07/02/2009 14:25:21 |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 07/02/2009 : 14:29:39
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Hi jcsifu
quote:
just substitue any new file name for the DSC00175 that is in this post?
Basically that's correct, you just have to change the file name,
in future uploads.
If you click on edit, on your above post, you will see I made a minor correction to your post.
And Isolated the active part of the image display HTML.
Nice photo by the way, very detailed.
Your screen name is very hard to pronounce.... 
Regards Dr. Bob |
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jcsifu
Copper Member
USA
47 Posts |
Posted - 07/02/2009 : 21:09:14
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quote:
Originally posted by Dr. Bob
Hi jcsifu
quote:
just substitue any new file name for the DSC00175 that is in this post?
Basically that's correct, you just have to change the file name,
in future uploads.
If you click on edit, on your above post, you will see I made a minor correction to your post.
And Isolated the active part of the image display HTML.
Nice photo by the way, very detailed.
Your screen name is very hard to pronounce....
Regards Dr. Bob
Thanx alot Dr. Bob.
My screen name is my initials and I was a Gung Fu teacher for 25 years, which the title given to a teacher is Sifu...so Jc+Sifu = jcsifu.
jc |
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Topic |
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ts-9 intermittent sound issue
