Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Speedo Problem

I had enough of my erratic Odometer LCD display in my 2002 4/4 so I thought I would investigate. Having stripped the VDO pcb out of the casing, I was using a hot air gun to see where the problem lay when a component on the pcb went pop. Guess I shorted it somehow as the ignition was switched on to see the jumping segments.
So now I need some help please. Does anyone know what part number is etched on the body of the IC? As you can see, mine has a big hole where this should be. I recognise the manufacturer logo = ‘Fairchild’ so with the correct part I can get it replaced at work and get lucky.
Here’s hoping……
Keith

Not the answer to your question but a G**gle search found two firms in this area:

www.speedycables.com

https://ryanlinleyrestoration.co.uk/morgan-lotus-vdo-speedometers


Looking at the remaining numbers and Fairchild parts list, on the plus side, I think there is a good chance that you may have destroyed something which is a standard logic part rather than a custom device. So, if you can find the part number, it should be available.

Good luck.

That second link is interesting, thanks for posting Paul

It's quite likely to have taken something else on the board out if you shorted it is my experience of electronics, good luck anyway.
BHM had a complete unit in stock a while back I know, if you need one have a word with Sarah.

p.s. The flickering LCD display is a common fault caused by a faulty capacitor on the board. My Plus 8 has done it for 10 years now but if you take the unit indoors and dry it out it rectifies itself. It's seasonal for me and never occurs in the warmer weather. It's a Morgan and I love her idiosyncrasies I know what it is so leave it be, I dried it out once to learn but just carry on, if it was the speedo it would be worth serious consideration, well for a minute or half.

I have just sent my VDO speedometer to Ryan Linley for a refurb as my LCD display has given up the ghost altogether, also a 2002 car.

Ha Rich My sister Plus 8 also has the flickering LCD -which I tend not to worry about, so Morgan were consistent in their builds for a while then -all very ISO 9001 compliant . IE we do it the same always even if it is the wrong way.

Good to hear Murray, loving the consistency reference - you barely notice it after a while, glad sister is keeping well.

Keith, the Fairchild chip looks quite but there are some black numbers stamped on it. You can try to remove them with alcohol or paint thinner so the white chip-type letters become readable. The beginning number looks like a "standard" chip from the 74AC??? logic family. If we can find out (and with some soldering skills) we can replace the chip hoping to bring it back alive.

Peter

If you feel confident in a self repair, perhaps Linley would sell you the relevant chip ?

For those with a faulty display VDO you can find replacement on AliExpress for about 15 £ here for example : VDO Tachometer LCD screen