Help needed with a TSL 100 head !!

[st220]

I have a Marshall TSL 100 head - model from 2001, symptoms before
i replaced the valves was a very loud background hummm.
As with some of the threads in this Forum i to had the runaway BIAS and that destroyed 2 of my JJ KT77's (cooked them).
I ordered a matched pair & while i was at it i replaced the 4 pre amp tubes
with JJ ECC83S.
After putting this lot in i BIASED the amp at 80mv per side and it appears to be stable even after 30mins off standby.
But....now comes the problem!!
The Clean channel works fine, loads of power & no background humm, the lead and crunch when selected are both DEAD, even at volume 10 only a faint output can be heard through my 1960a cab.
I have resulted in putting all the old tubes back in (the humm comes back), but the problem is exactly the same.
I have tried just about every tip i can find in these threads..
Cleaned & tweaked the valve sockets, checked all the PCB's for O/Heating, all the fuses are intact but still i have no LEAD or CRUNCH channels...anybody in these threads seen this before ?

[Jazz P Bass]

Marshall TSL 100

It sounds like a channel switching problem. Channel switching has nothing to do with the tubes, so put the tubes back that get rid of the hum.
Maybe someone can supply the schematic.

[booj]

jcm26402_ISS1.pdf

tl106002_ISS3.pdf

tl106102_ISS4.pdf

tl106202_ISS6.pdf

tl106302_ISS4.pdf

tl106502_ISS4.pdf

tl106601_ISS2.pdf

tsl100%20arch.pdf

Good Luck!!!!

[st220]

Marshall TSL 100 no lead or crunch

Thanks to Booj & Jazz for the replies.
Have done some more testing with the DMM and i agree it looks to
be one of the opto's that is not switching.
I'm OK with electronics, i used to repair CNC's for Robot Controllers,
however i'm looking for a thread where somebody has either suffered the same problem and fixed it or a schematic that's been labelled with several checking points showing voltages that should be detected with a DMM.
I did find one thread where a user described exactly my problem but all he said was his mate fixed it.
I'll still keep digging around however, i'm thinking of ordering a replacement main board because i've blown 2 JJ's using this one, what is a puzzle is the BIAS even after 60mins off stand-by is holding a balanced 80mv?

ST220

[drewl]

Did you rework the bias supply as per the Viva Analog page?

[st220]

Thanks to those that replied on this thread...
For anybody else that has this issue with the TSL 100 head, i took advice
from another user of this forum and ordered a new main power tube board direct from Marshall, total cost inc shipping (UK) was £63.00.

Fitted the new board & biased at 78mv and fixed, all channels as they should be !!

Bias holds firm even after 60mins off standby.

To add another point....the old 2001 board had "issue 5" written on it, the new board quotes "issue 20."
Placed side by side there are a number of component differences and additional comm connections on the new issue 20 board.

So this was the fix for my amp!

TS

[SidMEF]

I hate to reply to such an old thread but you mention using the TSL issue 20 board in place of the issue 5 board. I'm trying to do the same and also noticed three differences (so far) between the two boards. I have looked everywhere for an issue 20 schematic but no luck.

1) W14 (ground) spade connector is missing from the issue 20 board although it is marked in the silkscreen
2) Additional con15 connector on the issue 20 board
3) Additional con16 connector on the issue 20 board

How should I handle these differences?
Thanks

[st220]

I hate to reply to such an old thread but you mention using the TSL issue 20 board in place of the issue 5 board. I'm trying to do the same and also noticed three differences (so far) between the two boards. I have looked everywhere for an issue 20 schematic but no luck.

1) W14 (ground) spade connector is missing from the issue 20 board although it is marked in the silkscreen
2) Additional con15 connector on the issue 20 board
3) Additional con16 connector on the issue 20 board

How should I handle these differences?
Thanks

Hello,

It was sometime ago....
the replacement board I received from Marshall was from a Vintage modern amp, all the
original connections are on that board + there are additional connections you don't,t use
because you won,t have anything to connect. Make damn sure you label up every connection
And take photo,s of the board before you disconnect anything. If you get stuck come back to me coz I,m sure I still have photo,s of my original board. I take it you also received a vintage board ?

[SidMEF]

Hello,

It was sometime ago....
the replacement board I received from Marshall was from a Vintage modern amp, all the
original connections are on that board + there are additional connections you don't,t use
because you won,t have anything to connect. Make damn sure you label up every connection
And take photo,s of the board before you disconnect anything. If you get stuck come back to me coz I,m sure I still have photo,s of my original board. I take it you also received a vintage board ?

I could have but the board numbers match up with the existing TSL board. I haven't thought about it but it makes some sense for Marshall to designd a board that could be used in multiple amps. The thing that concerns me is the missing w14 ground connnector. Is it missing on purpose or was it an oversight in production. Did your new board have the W14 connector?
Thanks for responding.

[st220]

I could have but the board numbers match up with the existing TSL board. I haven't thought about it but it makes some sense for Marshall to designd a board that could be used in multiple amps. The thing that concerns me is the missing w14 ground connnector. Is it missing on purpose or was it an oversight in production. Did your new board have the W14 connector?
Thanks for responding.

Yes!!

But I've just looked at the old blown board and w14 is the ground & if you turn the board over w8 is at the opposite end and is also connected to ground, so if you don't have a w14 connection on your replacement you could always "piggy back" off w8.

[SidMEF]

Yes!!

But I've just looked at the old blown board and w14 is the ground & if you turn the board over w8 is at the opposite end and is also connected to ground, so if you don't have a w14 connection on your replacement you could always "piggy back" off w8.

I see what you are saying - both boards have W14 and W8 as grounds but the old board didn't use W8. It appears Marshall made an error since one issue 20 board has W14 and the other doesn't. So, I guess I could return the board for a correct board, run a longer lead acroos the amp to W8, or install a spade connector in W14. I think I will install the spade connector in W14.

Just to be sure your board is JCM2-60-00/ TL10-60-02?
Thanks

[st220]

I see what you are saying - both boards have W14 and W8 as grounds but the old board didn't use W8. It appears Marshall made an error since one issue 20 board has W14 and the other doesn't. So, I guess I could return the board for a correct board, run a longer lead acroos the amp to W8, or install a spade connector in W14. I think I will install the spade connector in W14.

Just to be sure your board is JCM2-60-00/ TL10-60-02?
Thanks

My old board is a JCM2-60-00.

Why do you need to run a supply to w8 ??
When you labelled up all the connections did you have lead & spade for w8 & w14 ?
As long as you have a least 1 connection to w8 or w14 then the board is grounded, if you do
Have a spade & lead for w8 & w14 then connect the both.
Did you buy the board direct from Marshall & quote the serial number of your amp ?

[SidMEF]

My old board is a JCM2-60-00.
my
Why do you need to run a supply to w8 ??
When you labelled up all the connections did you have lead & spade for w8 & w14 ?
As long as you have a least 1 connection to w8 or w14 then the board is grounded, if you do
Have a spade & lead for w8 & w14 then connect the both.
Did you buy the board direct from Marshall & quote the serial number of your amp ?

I appolize, I have not been clear. I don't have an easy connection to either W14 or W8 based on my situation. My TSL122's old board had the chassis to board ground connection at W14, not W8 but had spade connectors at both. The new board has the spade connector at W8 only.

No, I bought my board from Hot Rox UK. The price was too good to pass up. (...when a deal seems too good to be true you...) When I talked to several folks they said this board is all they have as a replacement.
Thanks

[st220]

I appolize, I have not been clear. I don't have an easy connection to either W14 or W8 based on my situation. My TSL122's old board had the chassis to board ground connection at W14, not W8 but had spade connectors at both. The new board has the spade connector at W8 only.

No, I bought my board from Hot Rox UK. The price was too good to pass up. (...when a deal seems too good to be true you...) When I talked to several folks they said this board is all they have as a replacement.
Thanks

OK. So connect your old board spade w14 to the new board w8, ground is ground!
I agree from your earlier note that you will have to increase the length to reach the post.
I take it that everything else was OK (all the same) with the exception of somewhere to
Plug w14 ?

[SidMEF]

OK. So connect your old board spade w14 to the new board w8, ground is ground!
I agree from your earlier note that you will have to increase the length to reach the post.
I take it that everything else was OK (all the same) with the exception of somewhere to
Plug w14 ?

From a quick look two other things were different. There were con15 and con16 connectors on the new board that were not on the old board. The layout and everything else looked pretty much the same in layout. I haven't gone through each component. I did notice that most of the resistors were metal film versus carbon on the old board, C46 (if I remember correctly) was beefed up, and the board looked of much better quality.