Aston Martin Virage. Electronic Info Centre problems.

[Murphyv310]

Of course we are talking about an expensive car in the first place. Now 25 years down the line it could and will be someone's pride and joy. Most car owners of the ilk will want it as per original spec so a suitable fix that is invisible to the customer is required. By that I mean the IPK has to function exactly like it did.
I'm not familiar with the Dallas chips nor any of these on the board but can the original voltage stabilization not be substituted and is the internal lithium battery not directly connected to the chips pins? Perhaps a little helping voltage might work.
Both bodges I know but what other options are there?

I've now been able to open up the link on page 1 and yes some chip surgery is needed.

[Nick]

You can't just try to force the lithium battery - its not rechargeable and should not be messed with.

The correct solution is to replace it with the new part as per Maxim's suggestion (I mentioned that in my original post - DS12887-series), however, if you wish to continue using the original part, the original lithium cell must be removed and replaced with a CR coin cell (again, as mentioned in my original post). Failure to remove the cell may well result in it leaking and causing serious damage to the PCB and surrounding components - I have had exactly this issue on both Tek 246x-series 'scopes and HP function generators - it's not a good place to be

The real problem here is in the contents of the 50 bytes of CMOS battery-backed RAM in the DS1287 - this may well contain the odometer data as well as other configuration information and possibly (almost certainly) a checksum to check for data corruption/clocking(!) etc. 

Somewhere there will be some DOS-based diagnostic software for this unit that will allow it to be reset after the RAM is replaced - maybe a mainstream AML dealer will have it or someone on one of the AML fora? Its amazing how often this stuff survives

So, either do the hack I mentioned (replace the battery) or replace the whole DS1287 with a later unit (DS12887).

Whichever you chose, the contents of the RAM still needs to be sorted out.

[Nick]

This is an interesting project - I have rescued similar units in the past, but not an AML one.

It seems that AML passed on work on the Virage & Lagonda electronics to an old ex-employee who subsequently retired (and according to some, died). AML then bought the test rigs etc. but did nothing with them, so there is hope that if pushed, or someone with a sympathetic ear is found, access to such data might be available (speak to the Heritage Operations Department).

Also, as very few Virages were made, there was no great depth of expertise around, even within AML, hence the difficulty in sorting this sort of problem...

Also, looking at the photo, there is an 8Kx8 static RAM next to the RTC - this does have a low power mode but being static RAM, will maintain contents in a low-power mode with just 2V on Vcc. Its static-sensitive, so handle it with care.

First things first - fix the RTC

[Geordie McBoyne]

There is no shortage of Dallas DS12778 RTC chips on eBay.    I'll order a couple, keep one as a spare.   The info centre has been returned to the shop.   I'll open it up again tomorrow.

Read about the AM Virage here:    https://en.wikipedia.org/wiki/Aston_Martin_Virage

Geordie McBoyne.

[Geordie McBoyne]

A new DS12778 RTC chip has been fitted.  To facilitate future replacement an IC holder is used.  Everything works, except for one problem, the mileage has jumped 30,000 beyond the original reading!   So we are looking for some method of resetting the reading back to the correct figure. 
The owner of another AM Virage has reported a similar problem.  It's likely the RTC chip is playing up. 
 
Any ideas?

Geordie McBoyne.

[Murphyv310]

You can't just try to force the lithium battery - its not rechargeable and should not be messed with.

The correct solution is to replace it with the new part as per Maxim's suggestion (I mentioned that in my original post - DS12887-series), however, if you wish to continue using the original part, the original lithium cell must be removed and replaced with a CR coin cell (again, as mentioned in my original post). Failure to remove the cell may well result in it leaking and causing serious damage to the PCB and surrounding components - I have had exactly this issue on both Tek 246x-series 'scopes and HP function generators - it's not a good place to be

The real problem here is in the contents of the 50 bytes of CMOS battery-backed RAM in the DS1287 - this may well contain the odometer data as well as other configuration information and possibly (almost certainly) a checksum to check for data corruption/clocking(!) etc. 

Somewhere there will be some DOS-based diagnostic software for this unit that will allow it to be reset after the RAM is replaced - maybe a mainstream AML dealer will have it or someone on one of the AML fora? Its amazing how often this stuff survives

So, either do the hack I mentioned (replace the battery) or replace the whole DS1287 with a later unit (DS12887).

Whichever you chose, the contents of the RAM still needs to be sorted out.

Hi.
I'm aware you cannot force feed a lithium battery. One reason I mentioned " chip surgery". Fortunately David has now been able to sort this out with the exception of the odometer reading.

[Geordie McBoyne]

I have another AM Virage info centre module to repair and with luck it might once again be failure of the Dallas "Timekeeper" chip.  Today, I collected a DS12887 IC  from the Aston Garage.  After the device has been fitted and the module is reinstalled in the car I will report back the results. The replacement IC appears to have the date code "1412" so hopefully this example is of recent production.

Of course what the car needs really needs is a replacement module.  However, the odometer and trip meter is part of the display. Perhaps a conventional speedometer with odometer could be sourced and fitted.  Other functions performed by the module will be the fuel gauge and clock. I'm told that other less important functions are things like boot lid open and maybe a reminder to wear the seat belts.

Later Virage cars do not employ this unit.
See Attached pictures of the cockpit of a 1994 model.

Geordie McBoyne.  

[Murphyv310]

I'll contact a friend on the Rover forum David that can help you out. I'll let you know soon.

[Geordie McBoyne]

The DS12887 timekeeper IC and other problems with the AM Virage are discussed in this forum:

http://www.mcaughtry.com/virage/

Geordie McBoyne.

[Geordie McBoyne]

Have fitted the replacement timekeeper chip.  Like the previous info centre module I've mounted the new IC on a holder, this will make replacement easier if ever the device needs replacement again.  
Today, the unit was delivered to the Aston Garage.  We'll learn in a few days time if the unit proves to be serviceable.
What really is required is a replacement module.   The info centre performs the following functions: the odometer and trip reading. Average speed and ETA. The time and date. Fuel used, instant consumption and average consumption.
Well I'm sure the clock can be replaced by a conventional analogue one. Likewise the fuel gauge.
The odometer and trip can be incorporated in speedometer.  In fact the later versions of the Virage are made this way and the dashboard looks all the better for it.
Check out the attachments.  The info centre module was replaced by traditional circular instruments in 1995.
Geordie McBoyne.