Sansamp repair

[Marky L]

Hi

I have a Sansamp BDDI and one of the selector buttons (the first one) won't engage any more. I did contact Tech 21 to see if there was an official repair centre in the UK, but no. Therefore.. does anyone know a good electronic engineer/repairer more versed in music equipment that could fix it? (I'm in the Bournemouth area if there is anyone local.)

 

Thanks

Edited Sunday at 10:57 by Marky L

[Phil Starr]

I opened mine up and gave the inside of the switches a good squirt of Servisol (switch cleaner) no further problems to date.

 

I run mine on batteries, I find that if the batteries are getting close to dead the switches don't work as they should. Remember these aren't actual swiches, which are in the electronics, they just send a signal that you want to change something and if the batteries need changing then you don't have enough power for the programmable to work

 

Paging @Chienmortbb

 

 

Edited yesterday at 06:09 by Phil Starr

[Marky L]

39 minutes ago, Phil Starr said:

I opened mine up and gave the inside of the switches a good squirt of Servisol (switch cleaner) no further problems to date.

 

I run mine on batteries, I find that if the batteries are getting close to dead the switches don't work as they should. Remember these aren't actual swiches, which are in the electronics, they just send a signal that you want to change something and if the batteries need changing then you don't have enough power for the programmable to work

 

Paging @Chienmortbb

 

 

Thanks

I am a klutz when it comes to electronics and was a little concerned that I'd end up making things worse. I have Servisol, I have screwdrivers.. maybe I'll have another look. 😬🤞

 

I run mine on mains BTW.

Edited yesterday at 06:47 by Marky L

[Chienmortbb]

Is it the Programmable BDDI?

 

I will admit to being ignorantly of the circuitry involved in the Sansamp BDDI, I will contact Tech 21 for more info.

 

Some questions, when working normally,  does the switch normally give a definite click when pushed? If not then they use some form or electronic switching. To stay true to their analogue circuitry, they are probably used IC based analogue switches. In the early days, these were frowned upon by the HiFi fraternity but they do allow simpler all along designs and the use of momentary switches rather than mechanically latched ones. This should improve reliability.

 

I am based in the Conurbation (Poole), so happy to have a look at it.

Edited yesterday at 08:11 by Chienmortbb

[Marky L]

12 minutes ago, Chienmortbb said:

I will admit to being ignorantly of the circuitry involved in the Sansamp BDDI, I will contact Tech 21 for more info.

 

Some questions, when working normally,  does the switch normally give a definite click when pushed? If not then they use some form or electronic switching. To stay true to their analogue circuitry, they are probably used IC based analogue switches. In the early days, these were frowned upon by the HiFi fraternity but they do allow simpler all along designs and the use of momentary switches rather than mechanically latched ones. This should improve reliability.

 

I am based in the Conurbation (Poole), so happy to have a look at it.

As I recall, on turning it on, switch 1 is active. It disengages if pushed but then won’t engage (I need to double check). I’m sure it does click but will confirm when I get home later. 

 

i had a quick look before going to work this morning and noticed the spring on S1 is too short and not in contact with the pad. S3 is in contact. Pics attached. 
 

I may well take you up on the offer 😃👍 Thanks. 
 

Edited yesterday at 08:17 by Marky L

[Phil Starr]

8 minutes ago, Chienmortbb said:

Some questions, when working normally,  does the switch normally give a definite click when pushed? If not then they use some form or electronic switching. To stay true to their analogue circuitry, they are probably used IC based analogue switches.

Hi John, thanks for offering to help out, they are non latching momentary switches allowing some basic programming. A double tap saves the settings

[Marky L]

@Chienmortbb Ok a bit more info.

 

The faulty switch does seem to make a click sound as per the other functioning pair. 
 

When turning the unit on, S1 is lit up and active automatically. It DOESN’T disengage when clicking it. If you click one of the others, they go active. If you then go back and click on S1 nothing happens. 
 

Hope that makes sense. 
 

 

[Chienmortbb]

Ir looks like the foot switches just push a microswitch on the PCB below. After mechanical switches, microswitches are one of those components that are not that reliable. However, that fact that the spring is not con physically connected to the microswitch.

 

It looks like the spring has about 2 coils less on S1 than S3, although it does not look as though the sporing has broken. I have contacted Tech21 support for advice, but unless the PCB has moved away from the spring, it looks like a new spring may be all that is needed. 

[Phil Starr]

I think that pic is conclusive (though sometimes you can have more than one fault) You should be able to operate the swich manually (be gentle) with a pencil tip and get it to operate. The spring is to turn the stamp of a 16 stone bassist into a gentle push. You could try putting something soft on the bottom of the shortened spring to shim out the gap as a temporary fix while you wait for the replacement spring. A little rubber foot might work, or a piece of felt. Hang off with the Servisol until you've tested the switch. It doesn't so much clean the switch as move the dirt around so there are a limited number of times it will work in a semi-sealed microswitch

[Chienmortbb]

1 hour ago, Phil Starr said:

I think that pic is conclusive (though sometimes you can have more than one fault) You should be able to operate the swich manually (be gentle) with a pencil tip and get it to operate. The spring is to turn the stamp of a 16 stone bassist into a gentle push. You could try putting something soft on the bottom of the shortened spring to shim out the gap as a temporary fix while you wait for the replacement spring. A little rubber foot might work, or a piece of felt. Hang off with the Servisol until you've tested the switch. It doesn't so much clean the switch as move the dirt around so there are a limited number of times it will work in a semi-sealed microswitch

In this instance, any switch or contact cleaner will not work. Those tactile microsites are sealed and do not work in the same way as a traditional electro-mechanical switch. There may be a need for some lubricant in the actual stomp button to keep is moving freely. 

 

As @Phil Starr says, you can experiment with foam or felt pads between the springs and the switch, but be careful. Firstly, the switches themselves are not that robust and secondly, too much pressure may lead to the switch being activated permanently, as though your foot was always on the foot switch. Use the rubber end of a pencil or even a cotton buds to make sure that the switch itself is still operating correctly. 

[Marky L]

15 hours ago, Chienmortbb said:

Ir looks like the foot switches just push a microswitch on the PCB below. After mechanical switches, microswitches are one of those components that are not that reliable. However, that fact that the spring is not con physically connected to the microswitch.

 

It looks like the spring has about 2 coils less on S1 than S3, although it does not look as though the sporing has broken. I have contacted Tech21 support for advice, but unless the PCB has moved away from the spring, it looks like a new spring may be all that is needed. 

Thank you. I appreciate your help