Michael Inglis
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Last night the Standby/Low Power/High Power (On-Off-On) Rocker Switch on my DSL100HR decided to stop functioning on the low power setting and intermittently on the high power setting. And even when it was "working" it was weak due to a poor contact on the switch poles (i suspect it might have been a poor connection for awhile but wasnt bad enough that i really stopped to look into it). It was too late to repair (about 11:30 pm) so I decided to pull it out this morning and I figured while I was at it i would make a guide so other Marshall owners (or anyone with a rocker switch on any number of amps) could replace their faulty switches instead of having to go out and buy a new one.
So heres whats likely happening if your switch is faulty. In most cases youll find the pressure points that throw the rocker switch to one side or the other have had their springs compress over time which makes it so that the switch no longer has enough force to make a solid connection. Or another scenario you'll find in older amps, although i admit is less common in guitar amps, is that the contacts have become oxidized or are covered in dust/debris which is impeding a solid connection.
If your switch is oxidized then some contact cleaner followed up with a lubricant like dielectric grease (or ideally Deoxit F5 fader contact cleaner, which is a cleaner AND a lube. The lube is needed to prevent the contacts from reoxidizing once theve been cleaned).
But if your switch is suffering from poor contact pressure like in my first example, which it almost certainly is if its not working, then here is a quick guide to fix it.
-Repair Procedure
Gain access to the chassis of your amp, find the back of the offending switch. If its soldered in youll have to desolder the connections but dont forget to take pictures of where each wire goes or label them with tape before desoldering. In the case of the DSL100HR or 40CR (and hopefully your amp if its not one of those) youll find the wires are connected with spade connectors that just need to be disconnected. The first time you take them off it will take a bit of force and maneuvering. If they still wont come off cut off the heat shrink and use a small screwdriver to push in the clip thats holding the spade connector on. Once you've removed them once they should come off easier if you need to remove them again in the future. And dont forget to replace the heat shrink if you had to remove it.
Next take some channel lock pliers (or similar) and depress the tabs on the top and bottom of the switch thats holding it in the chassis. Once the tabs are depressed it should come out through the front of the amp with a little maneuvering. Once you have the switch out youll want to take a flat head screwdriver (not too small or it will damage the switch by putting to much pressure in one spot, try to use a flathead with a blade thats 5 mm wide or wider) and wedge it carefully into the front of the switch on either the left or right side of the rocker. Then gently pry the side of the switch body outwards so that the pin holding in the rocker can slide out of the switch body. Then do the same thing for the other side releasing the rocker all the way.
Once you have your rocker switch opened youll see two sets of contacts that look like seesaws (its the best thing i could think of to describe them give me a break lol). And on the back of the rocker youll see the pins that depress those "seesaw" contacts. What you'll then want to do is pull out the pins and the springs behind them. Then all you need to do is stretch each spring out a few mm. That will put some more contact pressure behind the pins allowing them to fully engage the contacts again.
At this point you could opt to clean off the grease that was on the switch contacts, clean the contacts with contact cleaner and then add some fresh grease. This is absolutely not necessary if your switch is clean. I did this just to be thorough. Just make sure to test your switch before you reassemble the amp. If its still not showing continuity then repeat the above steps adding another bit of length to the springs.
After doing this and reassembling your switch it should feel really snug again with a solid click like it had when it was brand new. Below is some pictures of the switch etc. I wish id had the time to take more as im sure a few of the screwdriver in the side of the switch could have been really helpful. But if anyone is attempting this repair and having trouble let me know and ill add some new pictures.
And if you read all that and decided that its not for you (its not that difficult but you will be working inside a tube amp and normal precautions need to be taken which isnt for everyone and thats ok) then you can just buy a replacement and have your tech replace it. For the Standby/ Low / High Power switch on a DSL the switch is just an ON-OFF-ON DPDT type. You'll easily find some online that will work but most have writing on them showing "I - O - II" for each of the positions but I imagine that could be removed from the switch without much trouble if it bothers you. And if that still simply wont meet your exacting standards contact Marshall (or Marshall USA if your in the states) and they should be able to point you in the direction of their switch manufacturer from whom you can order an EXACT replacement.
Lastly, dont neglect those warranties! If this is too much hassle for you and your warranty is still good then by all means find a authorized tech and have them swap in a new one or repair the existing one. Maybe you could even...i dont know....show them my guide lol. Might quicken your turn around time!
Anyways, i hope this helped someone. Let me know if you have any questions!
This next picture shows the rocker pin that will need to be slipped out past the switch housing using a screwdriver.
Switch with rocker removed
Rocker contact/pressure pins installed
Rocker pins removed, this is how you get to the springs
In this picture the left contacts are still how i found them, the right have been cleaned with contact cleaner and regreased (im very low on dielectric grease so for this application i just used a non conductive marine grease. I obviously recommend dielectric grease if you have some but any non conductive grease should be just fine. Or just leave the existing grease if your OCD is more under control than mine).
These next pictures show the wire color connection order in case anyone forgets to take pictures.
Top row
Middle Row
Last row, only one pole has a connection
So heres whats likely happening if your switch is faulty. In most cases youll find the pressure points that throw the rocker switch to one side or the other have had their springs compress over time which makes it so that the switch no longer has enough force to make a solid connection. Or another scenario you'll find in older amps, although i admit is less common in guitar amps, is that the contacts have become oxidized or are covered in dust/debris which is impeding a solid connection.
If your switch is oxidized then some contact cleaner followed up with a lubricant like dielectric grease (or ideally Deoxit F5 fader contact cleaner, which is a cleaner AND a lube. The lube is needed to prevent the contacts from reoxidizing once theve been cleaned).
But if your switch is suffering from poor contact pressure like in my first example, which it almost certainly is if its not working, then here is a quick guide to fix it.
-Repair Procedure
Gain access to the chassis of your amp, find the back of the offending switch. If its soldered in youll have to desolder the connections but dont forget to take pictures of where each wire goes or label them with tape before desoldering. In the case of the DSL100HR or 40CR (and hopefully your amp if its not one of those) youll find the wires are connected with spade connectors that just need to be disconnected. The first time you take them off it will take a bit of force and maneuvering. If they still wont come off cut off the heat shrink and use a small screwdriver to push in the clip thats holding the spade connector on. Once you've removed them once they should come off easier if you need to remove them again in the future. And dont forget to replace the heat shrink if you had to remove it.
Next take some channel lock pliers (or similar) and depress the tabs on the top and bottom of the switch thats holding it in the chassis. Once the tabs are depressed it should come out through the front of the amp with a little maneuvering. Once you have the switch out youll want to take a flat head screwdriver (not too small or it will damage the switch by putting to much pressure in one spot, try to use a flathead with a blade thats 5 mm wide or wider) and wedge it carefully into the front of the switch on either the left or right side of the rocker. Then gently pry the side of the switch body outwards so that the pin holding in the rocker can slide out of the switch body. Then do the same thing for the other side releasing the rocker all the way.
Once you have your rocker switch opened youll see two sets of contacts that look like seesaws (its the best thing i could think of to describe them give me a break lol). And on the back of the rocker youll see the pins that depress those "seesaw" contacts. What you'll then want to do is pull out the pins and the springs behind them. Then all you need to do is stretch each spring out a few mm. That will put some more contact pressure behind the pins allowing them to fully engage the contacts again.
At this point you could opt to clean off the grease that was on the switch contacts, clean the contacts with contact cleaner and then add some fresh grease. This is absolutely not necessary if your switch is clean. I did this just to be thorough. Just make sure to test your switch before you reassemble the amp. If its still not showing continuity then repeat the above steps adding another bit of length to the springs.
After doing this and reassembling your switch it should feel really snug again with a solid click like it had when it was brand new. Below is some pictures of the switch etc. I wish id had the time to take more as im sure a few of the screwdriver in the side of the switch could have been really helpful. But if anyone is attempting this repair and having trouble let me know and ill add some new pictures.
And if you read all that and decided that its not for you (its not that difficult but you will be working inside a tube amp and normal precautions need to be taken which isnt for everyone and thats ok) then you can just buy a replacement and have your tech replace it. For the Standby/ Low / High Power switch on a DSL the switch is just an ON-OFF-ON DPDT type. You'll easily find some online that will work but most have writing on them showing "I - O - II" for each of the positions but I imagine that could be removed from the switch without much trouble if it bothers you. And if that still simply wont meet your exacting standards contact Marshall (or Marshall USA if your in the states) and they should be able to point you in the direction of their switch manufacturer from whom you can order an EXACT replacement.
Lastly, dont neglect those warranties! If this is too much hassle for you and your warranty is still good then by all means find a authorized tech and have them swap in a new one or repair the existing one. Maybe you could even...i dont know....show them my guide lol. Might quicken your turn around time!
Anyways, i hope this helped someone. Let me know if you have any questions!
This next picture shows the rocker pin that will need to be slipped out past the switch housing using a screwdriver.
Switch with rocker removed
Rocker contact/pressure pins installed
Rocker pins removed, this is how you get to the springs
In this picture the left contacts are still how i found them, the right have been cleaned with contact cleaner and regreased (im very low on dielectric grease so for this application i just used a non conductive marine grease. I obviously recommend dielectric grease if you have some but any non conductive grease should be just fine. Or just leave the existing grease if your OCD is more under control than mine).
These next pictures show the wire color connection order in case anyone forgets to take pictures.
Top row
Middle Row
Last row, only one pole has a connection
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