Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Speedo Problem

Hi Keith
I have a 1999 4/4 I purchased from a dealer in 2019. Shortly after the purchase the odometer became intermittent with segments of characters coming and going. I am a retired electronics engineer and I knew immediately from my experience of similar problems on other pieces of equipment with LCD that the problem was almost certainly the LCD itself. Not wishing to compromise the warranty I didn't repairer it myself I found a company in Portsmouth that replace VDO displays They allowed me to keep the old one. The picture below is the old display. As in all these displays there is a ribbon cable ( in this case 6 way) that connects the display to the display driver electronics. One end of this cable has to connect the the LCD itself which is imbedded in glass. I don't know the details of how this electrical connection to glass is archived but I do know it can become very unreliable. I have tried in the past to repairer this type of connection with very little long term success. and found the only reliable way is to replace the complete LCD display. This is a fairly straight forward job but you do need to take extreme care. The cable is extremely fragile. The end that connects to the pcb board will be in a socket and there will be some sort of retaining method usually a section of the socket that can pulled gently outward to release the sockets grip on the cable you would need to look at the socket very closely to find the pull out section. Before removing the cable from the socket make a note as to which way round it goes. You can by a replacement display from hear https://www.akspeedo.com/vdo-lcd-repair.php

Thank-you to all my contributors. Under magnification the chip was a Fairchild 74HC240 which was replaced and I am pleased to report that I am back in business. I have decided to replace the display which is now on order with AliExpress. Further update to follow.