RPM measurements

[Chewbacka]

1 hour ago, croftie said:

Looks like the printed circuit is showing so yes possible DIP switches, perhaps for course settings,

 

Having worked in the electronics industry I know they sometimes leave ‘holes’ in things so the final test probes can connect to the item under test to inject test signals and confirm the outputs without needing human intervention.  Possibly this is a non-user port.

Also the numbers moulded into the case are in fact the PIN connector numbers and not the hole numbers.  If you look you will see the pins on the other side are marked 7 & 8.

[blackrose]

4 hours ago, WotEver said:

Could you take a shot straight down 3 with the little silver cover removed as in your first shot? It looks to me like that might be a little yellow pot at the bottom of the hole but I can’t be sure at the angle of the photo. 

I'll have a go tomorrow.

3 hours ago, croftie said:

Looks like the printed circuit is showing so yes possible DIP switches, perhaps for course settings,

 

Dip switches in here. Ok thanks

3 hours ago, Flyboy said:

As I said in post 91, some units do not have dip switches, I can't see any in there. I think they were only fitted for the after market to cover a wide of engines.

Ok, no dip switches! I'll use my magnifying glass next time

[TheBiscuits]

7 hours ago, blackrose said:

Anyway it's not quite as simple to adjust/calibrate as some were suggesting earlier in the thread.

Don't beat me too hard dude!  All the ones I have previously set up just have a simple screw adjust potentiometer on the back, so I assumed yours would too ...  

 

If you insist on buying this newfangled bluetooth hifi disco wifi canbus complicated stuff I'm not the person to ask! 

 

Try @nicknorman he uses the unnecessarily complicated stuff

 

 

[blackrose]

29 minutes ago, TheBiscuits said:

Don't beat me too hard dude!  All the ones I have previously set up just have a simple screw adjust potentiometer on the back, so I assumed yours would too ...  

 

If you insist on buying this newfangled bluetooth hifi disco wifi canbus complicated stuff I'm not the person to ask! 

 

Try @nicknorman he uses the unnecessarily complicated stuff

 

 

Don't get paranoid dude! I wasn't referring to anyone specifically.

 

The gadgets came with the boat but it's all nearly 15 years old so they can't be that complex surely?

[TheBiscuits]

2 minutes ago, blackrose said:

Don't get paranoid dude! I wasn't referring to anyone specifically.

 

The gadgets came with the boat but it's all nearly 15 years old so they can't be that complex surely?

I was the one you quoted

 

15 years in the marine industry?  That's newfangled that is.  Some of us think the sail will never beat the galley slave....

[blackrose]

19 hours ago, TheBiscuits said:

I was the one you quoted

 

 

 

No you weren't! Your eyes have decided you. Look again at post #90. I didn't quote anyone. ?

Edited December 3, 2018 by blackrose

[blackrose]

13 hours ago, blackrose said:

decided

deceived

[Floating Male]

If all else fails you could try this;-

I was advised when I joined my last employment that they used to calibrate instruments by injecting known values and marking the values on a blank scale. They employed a man whose sole role was doing this!

He was an artist rather than an engineer I guess.  ?

So all you need is a sticky label and a biro.

[blackrose]

On 04/12/2018 at 18:39, Floating Male said:

If all else fails you could try this;-

I was advised when I joined my last employment that they used to calibrate instruments by injecting known values and marking the values on a blank scale. They employed a man whose sole role was doing this!

He was an artist rather than an engineer I guess.  ?

So all you need is a sticky label and a biro.

Thanks. I've got a labeller so I've already done it, but at some point I'll calibrate it properly.

[bizzard]

3 minutes ago, blackrose said:

Thanks. I've got a labeller so I've already done it, but at some point I'll calibrate it properly.

Better than bending the needle.

[Floating Male]

55 minutes ago, bizzard said:

Better than bending the needle.

I tempted to mention this seems like almost a U turn, although a J turn would fit better. ☺

Edited December 5, 2018 by Floating Male
clarification

[Flyboy]

On 05/12/2018 at 20:01, blackrose said:

 at some point I'll calibrate it properly.

Have you looked up hole 3 with the green lump at the bottom yet ?    Is it a push button or a rotary pot ?

[blackrose]

On 13/12/2018 at 15:49, Flyboy said:

Have you looked up hole 3 with the green lump at the bottom yet ?    Is it a push button or a rotary pot ?

I haven't had a chance to do this until today. I tried to calibrate it properly this morning using the Analogue (Pointer) Calibration instructions on page 4, https://j109.org/docs/vdo_programmable_tach_with_hourmeter.pdf 

 

Unfortunately as the led hours display on my meter doesn't always work - and wasn't working this morning, so I couldn't do it. It's adjusted by push button inside a deep hole (3) so that's a pain too because you need to use a thin screwdriver to push it. The whole adjustment process is vastly over-complicated. I don't know why they couldn't just have designed it with a dial or screw on the back that you could turn without having to use the led display. Really poor design in my opinion.

Edited December 22, 2018 by blackrose

[Flyboy]

1 hour ago, blackrose said:

I haven't had a chance to do this until today. I tried to calibrate it properly this morning using the Analogue (Pointer) Calibration instructions on page 4, https://j109.org/docs/vdo_programmable_tach_with_hourmeter.pdf 

 

Unfortunately as the led hours display on my meter doesn't always work - and wasn't working this morning, so I couldn't do it. It's adjusted by push button inside a deep hole (3) so that's a pain too because you need to use a thin screwdriver to push it. The whole adjustment process is vastly over-complicated. I don't know why they couldn't just have designed it with a dial or screw on the back that you could turn without having to use the led display. Really poor design in my opinion.

It's called progress.  If you warm it up with hair drier it will probably display ok.

[Jen-in-Wellies]

Are you sure it is an LED (Light Emitting Diode) and not an LCD Liquid Crystal Display? LCD is more usual on modern electrogadgetry tacho's. What @Flyboy said. If it is an LCD display, black digits on a grey background, they don't like getting cold and damp. Remove the tacho and stick it in an airing cupboard, or other warm dry spot for a day or so and there is a good chance it will come back to life. It is still counting hours, just the display isn't.

 

Jen

[Flyboy]

2 hours ago, Jen-in-Wellies said:

Are you sure it is an LED (Light Emitting Diode) and not an LCD Liquid Crystal Display? LCD is more usual on modern electrogadgetry tacho's. What @Flyboy said. If it is an LCD display, black digits on a grey background, they don't like getting cold and damp. Remove the tacho and stick it in an airing cupboard, or other warm dry spot for a day or so and there is a good chance it will come back to life. It is still counting hours, just the display isn't.

 

Jen

There is a common problem with these VDO units where the ribbon cable is bonded to the rear of the LCD display. This COG (Connection On Glass) bonding is covered with a silicone rubber type compound which is supposed the keep moisture out, however this breaks down in time and lets the moisture in. The hours meter will still record and remember the hours. If you want to repair your unit, have a look at the pdf file or YouTube links below. Most modern engine marinisers use the VDO tacho  ie Yanmar, Barrus, Beta, Isuzu, Volvo, Canaline and others.

Repair of Yanmar Tach updated (2).pdf

https://www.youtube.com/watch?v=eldRUU7qc2Y

 

Edited December 22, 2018 by Flyboy

[WotEver]

1 hour ago, Flyboy said:

This COG (Connection On Glass) bonding is covered with a silicone rubber type compound which is supposed the keep moisture out, however this breaks down in time and lets the moisture in.

Back when I used to repair stuff Sony had a problem with their professional VTRs. These things cost £35k in the early 90’s. There was a metal filter module which had a resin ‘protective layer’ on the rear of it. After a number of years that would break down and become semi-conductive. The fix was to desolder the filter (about a dozen pins), clean off all the old resin with Xylene, then re-solder it into position. Magic fix that took 10 minutes. 

[Flyboy]

5 minutes ago, WotEver said:

Back when I used to repair stuff Sony had a problem with their professional VTRs. These things cost £35k in the early 90’s. There was a metal filter module which had a resin ‘protective layer’ on the rear of it. After a number of years that would break down and become semi-conductive. The fix was to desolder the filter (about a dozen pins), clean off all the old resin with Xylene, then re-solder it into position. Magic fix that took 10 minutes. 

I'll never understand why Seimens who make these VDO tachos for boat use can't use a decent sealant on these COG substrates. There's been trouble with these units for at least 10 years and they've done nothing to correct it.

I had a similar problem on my car clock and sorted it by heating the ribbon cable where it went on the LCD substrate with a flat iron. Problem solved. I think it was joined with heat sensitive conductive adhesive.

[Chewbacka]

5 minutes ago, Flyboy said:

I'll never understand why Seimens who make these VDO tachos for boat use can't use a decent sealant on these COG substrates. There's been trouble with these units for at least 10 years and they've done nothing to correct it.

I had a similar problem on my car clock and sorted it by heating the ribbon cable where it went on the LCD substrate with a flat iron. Problem solved. I think it was joined with heat sensitive conductive adhesive.

So long as the unit life is just long enough for people to buy replacements rather than a different brand then they have got it about right for max profit.

[Flyboy]

4 minutes ago, Chewbacka said:

So long as the unit life is just long enough for people to buy replacements rather than a different brand then they have got it about right for max profit.

Spot on.

[blackrose]

Ok thanks people, I'll calibrate the tacho in summer when it's warmed up and dried out.

[blackrose]

On 22/12/2018 at 20:38, Chewbacka said:

So long as the unit life is just long enough for people to buy replacements rather than a different brand then they have got it about right for max profit.

That might apply to the majority of items but it really depends on the business model used. Consumer products vary enormously in quality and longevity. Some expensive high spec products aren't designed to require reguar replacement and max profit is obtained by charging a premium and getting a reputation for good quality.