IS200/300 satnav - problem reading DVD

[br1anstorm]

I know it's not good to double-post.  But I've had zero response to a post I made into the audio/video/electronics/security forum. 

I'm also guessing that because the satnav systems vary so much in different models, the real experts in 1st-gen IS 200/300 satnav installations might be more regular contributors in this sub-forum.

The problem I have may be familiar to IS200/300 owners.  The satnav says it can't read the map DVD.  So the entire system no longer functions.

Full details are in my other post at https://www.lexusownersclub.co.uk/forum/topic/120319-is300-2002-satnav-cannot-read-disc/

I have removed and cleaned the DVD (which was neither dusty nor scratched);  and I have also run a lens-cleaner disc in the unit.  Still the screen says 'unable to read map DVD'.

What else can be done to solve the problem?  Or has the laser disk-reader suddenly failed completely?  Any advice would be welcome.

[scudney]

I would probably say it's the lens,when I had my IS200 sport navigator I remember buying the wrong disc off the bay and it came up with unable to read disc,please check disc,however once I managed to source a genuine disc it read it and was fine thereafter until I sold it,however in your case you haven't changed the disc so it's not the disc and the module seems ok by the sound of it too

[br1anstorm]

Thanks John (scudney) for your comments. 

My DVD is the original/genuine map disc, which has worked fine until now, so that's not the source of the problem.  I have run a disc lens-cleaner several times in the unit, so if there was dust or something on the laser-lens it should have been cleaned up.  But the screen still says "unable to read DVD".  I suspect this might mean the laser head itself may have failed or become misaligned.

My next step is to try a replacement DVD-reader unit.  Not a new one, but there are several used ones (out of scrap vehicles, no doubt) offered on the well-known online auction site.  My Lexus unit (which seems to be the same for both IS200 and IS300) is made by Denso and has the ref numbers 86841-53040.  It looks very much as if the unit used in the Toyota Avensis is the same:  it has the number 86841-53041. 

I wonder if anyone else has tried this "swap".  I'm aiming to try a second-hand Toyota unit.  Will report back on what I discover.  Maybe the screen will display a Toyota logo before it goes into navigation mode!

Depending on how that goes, I might then try to investigate and repair (?) the original unit.  Has anyone else dismantled/reassembled one of these, or found advice - in a repair-manual or on YouTube - on how to fix them?

[scudney]

If you can get a working denso one preferably the same as yours cheap enough its probably worth a gamble and that way you will also get to find out if its the unit that's faulty 

[br1anstorm]

Time for an update - and it's all good news.

Bought a used/second-hand satnav DVD unit (the box mounted under the boot floor) off the well-known auction site for a very modest price.  The one I bought was from a Toyota Avensis.  Made by Denso, with serial number 86841-53041.  Interestingly, it even came with the same mounting-brackets as are used in the IS200/300.

I swapped them over, connected the replacement one up - and hooray!   It works perfectly.  So this might be useful info for anyone else whose satnav says "unable to read DVD". 

In researching online, I have also learned that one possible explanation is that, with age, the power-supply to the laser head which "reads" the DVD does gradually reduce.  My Lexus (and its satnav) is 17 years old, so that seems the likely explanation.  There is a fix (explained on YouTube).  Basically you open up the unit and find the potentiometer which manages the power-supply to the laser.  Apparently there is an adjustment-slot which you can turn very carefully with a thin screwdriver or pocket-knife-blade to increase/decrease the voltage setting.  Too much, and the laser will burn out;  too little, and the laser isn't bright enough to read the DVD.

So I'm going to try that with the faulty unit which I have just removed, to see if that revives it.

[scudney]

Well done and good on you 👍👍