Yesterday I tested my Knocklink buy tapping next to the sensor with a spanner. I knew the first green light was intermittent but the first orange and red didnt work at all !!!.

Took the unit apart and the leds had "dry jointed" were they met the pcb board. considering how the leds are mounted and fixed it is a very poor design. I resoldered all the joints and it works fine now.

If you have a knocklink test it and make sure it is working, dont just really on it. My unit is only 4 months old and I had to resolder the sensor wire as well last month.

 

surely it must be covered under a 12 month guarantee.

Contact the seller and arrange to send it back.

 

Out of all products mentioned on SN, knocklink failures appear to crop up quite regularly, dry joints always being mentioned.
Are these things being made in someones kitchen as a sideline?
I'm going to need a knock meter next year - is there an alternative manufacturer?

Nick

 

Don't think failures have been that regular.

J&S Electronics do one. No idea of cost or suppliers in the UK.

 

Well thought my Knocklink had been rather quiet - removed pcb to check to find 3 of the 5 LEDS had broken/dry joints Resoldered now ok

Cheers

 

Checked mine when i first recieved it-it also had dry joints!!!!

 

Going to bring this back up and encourage people to test their Knocklinks regularly.

Just tested mine after it appeared to go quieter than normal.

Sure enough dry joints on all the LED's excpet the bottom green.

Also sensitivity control unit had one dry joint.

 

This has come up often. Checked mine when I got it and it needed soldering too!!

Easy to do, but consequences of not checking could be severe.

 

Mine is OK but I test it every few weeks just to be safe. Bit ironic we have to test our test equipment. Mine was flashing red when I put a conrod through the block

 

Want to fit mine today, had it apart, what does a dry joint look like?

 

The soldered joint has a slight discolourisation - easier way is to gently 'wiggle' the LED's and watch the joints, there should no movement if the joint is solid.
When fitted to car tap the bolt which secures the Bosch sensor to block (being careful not to hit and damage the actual sensor itself) this should if working correctly cause all the LED's to illuminate

Cheers

 

got the wife to tap the bolt and only the first green lit up


It used to have a permanent light at the bottom and it seems to have dissapeared and when flooring it in 3rd i would get a little activity now nothing
so i guess i had better investigate ASAP

 

Anyone know or have access to circuit diagrams to make a knocklink?

Just I find it disgusting at that price these thing retail at, which essentially is a few resistors and capcitors coupled to a LM3914 display driver chip and a naff looking plastic box - and even then you need to calibrate it yourself.

To add insult to the stupid prices the damn things are so badly soldered to gether that they fail to work properly

Sorry if this sounds a bit derogatory. But my opinion is why buy something that is so expensive and unreliable when you could make one yourself for less than £10.

Currently I'm investigating the net to see if there any design schematics I can use before creating my own - look out for a thread in the future when I start putting soldering iron to protoboard.

 

If you look at the back of the pcb it's quite a basic circuit to reverse engineer.

 

What size is the bolt hole in the block that is the recomended position for the sensor, was under the impression that it is a M8 x 30mm, but this doesnt seem to fit ie too tight?

 

Would piston slap set a knockling off?

 

I asked this question a while back and Bob Rawle said that it would. I'm pleased about that cos I've got a '98....

 

M8 x 30mm is correct
Do you have the proper fixing hole
Try this link
http://stefanostadal.homedns.org/car_mods_gauges.htm

 

Have looked at that yes, think i have the right hole, tried a bolt in it and managed to shear it off just when it started to get tight, so now have to extract stump and start again! Just fitted de-cat downpipe and so want to monitor knock now.

 

Must have sheared it off

Maybe you can use another hole to fit it ?

 

Will look again tommorow, after i have got other bolt out!