V Boost Controller issue

[GMac]

Hi Folks,

I bought a non runner '85 V Max and have got it almost back together. I connected up the battery the other day so I can set up the V boost adjustments. Unfortunately, when I turned on the ignition, the V boost did nothing.

After further reading, I did the flex and press on the controller and the boost servo sprung into life. However, when I turn on the ignition, the servo motor opens the valves fully but then does nothing. I have to manually pull the cable to close the boost valves. I thought it was meant to open and close the Boost valves on start up.

Questions are:
What should the Boost servo motor do when the ignition is turned on?
If the controller needs dry joints resolved, how do you remove the resin that encapsulates the Controller circuit?
Should I just try to buy a new controller?
Open to any other suggestions as to how to get this working.

Many thanks

Graham

 

[MaxMidnight]

Questions are:
What should the Boost servo motor do when the ignition is turned on?

When the ignition is turned on the V Boost will open and close.
Section 7-59 describes the operation of the V Boost and working through that would be a good place to start.

If the controller needs dry joints resolved, how do you remove the resin that encapsulates the Controller circuit?

Not done this

Should I just try to buy a new controller?

Only if yours can;t be fixed. New will be expensive so a good second hand one might be a better option.
Alternatively an Ignitech ignition can control the V Boost (+ things you didn't know you needed to control)

Open to any other suggestions as to how to get this working.

Wait for others to chip in.

 

[Fire-medic]

Sell that as a "VMax modified full-time VBoost electronic module" for someone who wants that sound the open VBoost provides at idle.

Then buy an Ignitech.

 

[GMac]

Thanks very much for your good advice.

The controller was very intermittent and pressing on various parts of the circut board made the servo do different things. With a reluctance to buying a replacement, I decided to remove the resin coating and to resolder the board. Nothing ventured, nothing gained!

Removing the resin was much easier that I first thought. The way to do this is to run a razor blade around the circuit board and then to carefully insert a thin screwdriver into the cut to lift the resin away from the board ( away from any circuit tracks). I lifted the screwdriver rather than levered it against the edge of the board to prevent stressing the board. With a little coaxing, the resin will come away in a single sheet.

Once resoldered, the controller works perfectly.

Cheers

Graham

 

[Fire-medic]

Congratulations on a $-saving repair, and in describing your method.

 

[Jack Hammer]

Excellent way of individual thinking. Keep doing that. Nevermind the rest.

 

[Rooster60]

Thanks very much for your good advice.

The controller was very intermittent and pressing on various parts of the circut board made the servo do different things. With a reluctance to buying a replacement, I decided to remove the resin coating and to resolder the board. Nothing ventured, nothing gained!

Removing the resin was much easier that I first thought. The way to do this is to run a razor blade around the circuit board and then to carefully insert a thin screwdriver into the cut to lift the resin away from the board ( away from any circuit tracks). I lifted the screwdriver rather than levered it against the edge of the board to prevent stressing the board. With a little coaxing, the resin will come away in a single sheet.

Once resoldered, the controller works perfectly.

Cheers

Graham

Will you reapply a protective coating to the board or simply leave it exposed?

 

[gtatt85]

Thanks very much for your good advice.

The controller was very intermittent and pressing on various parts of the circut board made the servo do different things. With a reluctance to buying a replacement, I decided to remove the resin coating and to resolder the board. Nothing ventured, nothing gained!

Removing the resin was much easier that I first thought. The way to do this is to run a razor blade around the circuit board and then to carefully insert a thin screwdriver into the cut to lift the resin away from the board ( away from any circuit tracks). I lifted the screwdriver rather than levered it against the edge of the board to prevent stressing the board. With a little coaxing, the resin will come away in a single sheet.

Once resoldered, the controller works perfectly.

Cheers

Graham

Hi Graham, I have the resin removed from the circuit board. Just curious what you soldered. Hoping I can get this one working. Any help is greatly appreciated.

 

[RempageR1]

You just resolder everything on the back of the unit. Vibrations can crack the soldering points to heating them and resoldering them fixes that.

 

[one2dmax]

The microcracks can be very difficult to see but not complete the circuit.

 

[MaxMidnight]

The black ring is a good indicator of where you nee to re-solder.

 

[brian hicks]

Thanks very much for your good advice.

The controller was very intermittent and pressing on various parts of the circut board made the servo do different things. With a reluctance to buying a replacement, I decided to remove the resin coating and to resolder the board. Nothing ventured, nothing gained!

Removing the resin was much easier that I first thought. The way to do this is to run a razor blade around the circuit board and then to carefully insert a thin screwdriver into the cut to lift the resin away from the board ( away from any circuit tracks). I lifted the screwdriver rather than levered it against the edge of the board to prevent stressing the board. With a little coaxing, the resin will come away in a single sheet.

Once resoldered, the controller works perfectly.

Cheers

Graham

Resolder as much of it as you can because these cracked joints can be very hard to see. Also spray the board afterwards with PCB varnish for protection.