2008 MY sat nav fix?
 

The Volvo sat nav is at best a "clunky" feature and I generally use my Tom Tom accessory. Today, I left the TT behind and needed to rely on the Volvo system. My main gripe with it is that it will not remember user programing such as voice, Miles/Km and, vitally, route. As soon as I turn it off and lock the car, the user memory is lost and it resets to factory defaults.

It occurs to me that the reason is loss of electrical power to the unit, and if I could rig up a permanent power supply its memory would be retained. Has anyone tried this?

Grubby

It already has a permanent supply and I'm not sure you're going to resolve it that way. It should retain all settings when the ignition is switched off so if it's not doing that then its probably just faulty. There will probably be a small CMOS battery on the PCB inside the DVD drive which has probably leaked or just failed.

Mine is of newer design, a navigator integrated with the Sensus 3.0 system. But for sure it remembers all settings between the different tours.

That's interesting - thanks.

'Er indoors also has a 2007 V70, and that exhibits exactly the same fault - neither sat nav has ever retained it's user memory. I spoke with Volvo a couple of years ago and, predictably, they said it was not repairable but I could have a replacement for c£2,000. Yeah - right.

I'll have to open it up and try and find the battery you refer to Simon - your diagnosis makes perfect sense.

Anyone with electronics expertise out there able to guide me as to visual recognition of the component I am looking for?

Cheers

However another likely possibility (I've never had mine apart so I don't speak with certainty here) is that it makes use of non-volatile storage technology (i.e. similar to that used in USB sticks and such devices), as do many of the vehicle's other modules and sensors which need to retain reconfigurable programming and settings when not powered. IF that is the case, then you'd be looking a component level repair to the affected board, if that were even possible.

There are quite a few members who have some electronics experience. If you're brave enough to crack the unit open at your own risk, and post some good, high-res pictures of the internals, I'm sure we'll try to help if possible.

But I for one don't know in advance what is actually inside that unit.

Yes, I am such a person

I have repaired radios and other devices with failling memories

In the Automotive world they do NOT use little batteries to retain settings when power is off

They use non volatile flash memory, just like your mobile phone does, but much smaller

On devices I have repaired in the past the memory chip was easy to replace and cost all of 1.50 EUR.
BUT you have to have a memory chip reader to read out the contents of the old flash to then store in the new flash.
Even way back then, 15 years ago, I used a friends workshop where he had such tools

Given that a new nav drive is only around 250 EUR on eBay, you may be better with a 2nd hand drive

Be aware of the 2nd hand issues:
1. You have no clue as to how good or bad the 2nd hand drive is
2. You need to ensure the replacement has the identical part number to yours - vitally important
3. The part number should be enough but you need to ensure it is the same type of nav

Otherwise I have a friend in Germany who repairs nav drives, he is an professional electronics guy with his own business. He has all the kit, but he would have to say whether he'll accept it for looking at or not.

In the Automotive world they do NOT use little batteries to retain settings when power is off

They use non volatile flash memory, just like your mobile phone does, but much smaller

On devices I have repaired in the past the memory chip was easy to replace and cost all of 1.50 EUR.
BUT you have to have a memory chip reader to read out the contents of the old flash to then store in the new flash.
Even way back then, 15 years ago, I used a friends workshop where he had such tools

Have understood this correctly:- The user memory is retained as long as a power supply is connected; the memory chip which retains that data when the power supply is disconnected has failed; therefore is it not a practical solution to connect a permanent power supply to overcome failure of the memory chip? This would by-pass the need for a technically specialist repair or risky second hand replacement.

Grubby

The nav is already connected to the +30 permanent 12V battery supply on pin A1 of the power connector of the nav

The non-volatile memory is normally a flash memory (a re-writable EEPROM) and they can and do fail.

Here's the type of device I used to work on: a BMW navigation computer
http://i61.tinypic.com/2upxwcx.jpg

In the bottom right you see the flash memory - 2 pieces of flash memory fitted and it looks like 2 pieces of other flash fitted, with room for up to 4 more pieces.
Surface mount components that are impossible to read and remove and replace and reprogram without the right tools and experience.

It might help you to think of this in another way.

Namely; your problem is not that the module loses power, causing data to be lost from storage. It is that the faultly (flash) memory components don't allow that data to be stored in them in the first place; they can no longer be reliably written to even when they have power applied normally.

The net result is the same - adding an additional power feed won't help. You are faced with repair, replacement, or living with it.

The reason that the system appears to work ok when you're using it is that when you make changes to settings you are doing so in temporary storage (RAM, which is depdendent on having power applied) and this is working ok, so everything appears to work normally. However the same changes cannot also be saved to the long-term storage (FLASH, holding the same data when powered off), because it is damaged, so they cannot be recalled when the system is next started.