W202 Flip key - MBClub UK

vtechnician · 28-06-2012, 08:35 PM

Its been a while since I've been on the forum.I have posted a thread on this subjet before but I have now found additional symptoms.
I cannot seem to figure out the problem with this key on my dad's C230.
The batteries keep on getting flat,I have been through alot of them,different makes etc.
What I did notice is that when putting in new batteries, and then checking the infra-red with a cellphone camera, it works normal sometimes and then the sinal remains on as if the button is depressed.
I thought that it might be the switch that sometimes remains in the depressed position.Opened up the key and tested the switch and even opened it up and re-assembled the switch.The switch turned out to be fine when testing it with a multimeter.

What I also noticed is that when connecting one battery to the circuit board when it is out of the housing, the signal is very bright-strange.
I am not sure if this was when the switch was depressed or not.Will re-test it again and post.
I do not want to replace the factory alarm with an aftermarket one as some aftermarket alarms require extra modules to close the windows and sunroof,some modules only close and cannot open the windows and sunroof.
Any help and advice appreciated.

Dec · 28-06-2012, 10:46 PM

Do You see anything out of place when you compare to the picture below.

Dec

vtechnician · 29-06-2012, 08:58 PM

As I stated before,I did all of those tests and even tested the switch.
The problem is that the batteries keep getting flat.
Thanks for replying

vtechnician · 29-06-2012, 09:21 PM

The other problem is that sometimes when checking with the camera, the transmitter signal remains lit up even when releasing the button.

Dec · 30-06-2012, 09:47 AM

It has t be a faulty tactile switch, I know you tested it but it does sound like the switch.
The fault did come with the remote when you bought the car so you don’t know what the last owner was up to… perhaps he resoldered the switch back on the PCB the wrong way around.

I believe (not certain about that) that there is only 3 of the 4 legs on the switch used in the circuit and the forth leg is just to support the switch on the PCB.
You could try another switch from Maplins … Tactile Switches : Push Switches : Maplin Electronics

Test the switch again only do it out of its shell to se if this reveals any new information as to the reliability of the switch.
See the video linked below which also has a remote with your symptoms.
Mercedes w202 key and remote test and repair. battery test - YouTube

Any chance of a close up picture of both sides of the PCB.

Dec

28-06-2012, 08:35 PM	#1
vtechnician New Member Join Date: Feb 2012 Car: mercedes c230 w202 Posts: 22	W202 Flip key Its been a while since I've been on the forum.I have posted a thread on this subjet before but I have now found additional symptoms. I cannot seem to figure out the problem with this key on my dad's C230. The batteries keep on getting flat,I have been through alot of them,different makes etc. What I did notice is that when putting in new batteries, and then checking the infra-red with a cellphone camera, it works normal sometimes and then the sinal remains on as if the button is depressed. I thought that it might be the switch that sometimes remains in the depressed position.Opened up the key and tested the switch and even opened it up and re-assembled the switch.The switch turned out to be fine when testing it with a multimeter. What I also noticed is that when connecting one battery to the circuit board when it is out of the housing, the signal is very bright-strange. I am not sure if this was when the switch was depressed or not.Will re-test it again and post. I do not want to replace the factory alarm with an aftermarket one as some aftermarket alarms require extra modules to close the windows and sunroof,some modules only close and cannot open the windows and sunroof. Any help and advice appreciated.

28-06-2012, 10:46 PM	#2
Dec Hardcore MB Enthusiast Join Date: Jul 2004 Car: C180,A. September '97 17k Posts: 1,544	Do You see anything out of place when you compare to the picture below. Dec

29-06-2012, 08:58 PM	#3
vtechnician New Member Threadstarter Join Date: Feb 2012 Car: mercedes c230 w202 Posts: 22	As I stated before,I did all of those tests and even tested the switch. The problem is that the batteries keep getting flat. Thanks for replying

29-06-2012, 09:21 PM	#4
vtechnician New Member Threadstarter Join Date: Feb 2012 Car: mercedes c230 w202 Posts: 22	The other problem is that sometimes when checking with the camera, the transmitter signal remains lit up even when releasing the button.

30-06-2012, 09:47 AM	#5
Dec Hardcore MB Enthusiast Join Date: Jul 2004 Car: C180,A. September '97 17k Posts: 1,544	It has t be a faulty tactile switch, I know you tested it but it does sound like the switch. The fault did come with the remote when you bought the car so you don’t know what the last owner was up to… perhaps he resoldered the switch back on the PCB the wrong way around. I believe (not certain about that) that there is only 3 of the 4 legs on the switch used in the circuit and the forth leg is just to support the switch on the PCB. You could try another switch from Maplins … Tactile Switches : Push Switches : Maplin Electronics Test the switch again only do it out of its shell to se if this reveals any new information as to the reliability of the switch. See the video linked below which also has a remote with your symptoms. Mercedes w202 key and remote test and repair. battery test - YouTube Any chance of a close up picture of both sides of the PCB. Dec

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