HUD issue
Thread Starter
Drifting
Joined: May 2003
Posts: 1,979
Likes: 48
From: Lakeport CA
HUD issue
Client car, complaint of hud not staying on.... Sure enough, key on, HUD is bright, clear & runs through all self diagnostics. Buttons function for page, & display up down works smooth. After a few min, hud goes dim & then out.... Key off, back on, right back on.
Pulled dash, check connections. Sprayed with high end (aircraft) contact cleaner/protectant.... no change. Pull dash all apart, pull hud button/controls apart. resolder almost all joints. Only a few looked suspect. Contact cleaner in the slider, gentle clean of contact buttons. Pull IP back off. Resolder pins for HUD plug, power transistors right under plug that traces appear to head into.... All back together... no change.
HUD ALWAYS comes on with initial key on. Start car & hud goes out...
Open to suggestions for next step...
TIA!
Pulled dash, check connections. Sprayed with high end (aircraft) contact cleaner/protectant.... no change. Pull dash all apart, pull hud button/controls apart. resolder almost all joints. Only a few looked suspect. Contact cleaner in the slider, gentle clean of contact buttons. Pull IP back off. Resolder pins for HUD plug, power transistors right under plug that traces appear to head into.... All back together... no change.
HUD ALWAYS comes on with initial key on. Start car & hud goes out...
Open to suggestions for next step...
TIA!
Thread Starter
Drifting
Joined: May 2003
Posts: 1,979
Likes: 48
From: Lakeport CA
Not a spare.... Not sure my other clients will like me pulling their IP to test someone else's car.... Some further research last night indicates it might be the light sensor inside the HUD.... and with the way it comes on bright & then goes dim before out... Hopefully this evening I will have time to pull the dashpad & find out. Other cars to work on this AM.
Melting Slicks
Joined: Jan 2009
Posts: 3,275
Likes: 739
From: Miami FL
Drifting
Joined: Jun 2013
Posts: 1,957
Likes: 342
From: Shell Point (Crawfordville) Florida
My HUD went out suddenly and it is not due to the motor failing or the tab breaking as I can see the mirror moving when I use the height control. I have no light visible when looking anywhere inside the unit, even in the dark, I have been asking in my thread if anyone knows about that photocell and no one has responded to me, but l did see a video on YouTube by a guy who repaired that by soldering together the 2 posts in photo #3 above that are on the opposite end from the photosensor, (upper left corner, near the screw) thereby bypassing the sensor and giving brightness control only to the dimmer switch, not automatically day vs. night, as us the function of that sensor. That fixed his failed HUD and rather than searching for a replacement, you might try that and see if it works, The repair is easily undone if you don;t want it that way and decide to replace the sensor.But if it works after that and does not die, that will tell you for sure the behavior was due to a bad photosensor.
I would be very interested if it works after you do that, before I rip apart my entire dash to get to mine and try that fix.
I would be very interested if it works after you do that, before I rip apart my entire dash to get to mine and try that fix.
Last edited by mrlmd; Mar 14, 2019 at 07:39 PM.
Melting Slicks
Joined: Jan 2009
Posts: 3,275
Likes: 739
From: Miami FL
...soldering together the 2 posts in photo #3 above that are on the opposite end from the photosensor, (upper left corner, near the screw) thereby bypassing the sensor and giving brightness control only to the dimmer switch, not automatically day vs. night, as is the function of that sensor...
I had read about connecting together the sensor's terminals, which permanently sets the HUD in its brightest mode with no autodimming and totally dependant of the manual dimmer, and was wondering if the photosensor could be identified so it could be replaced instead.
@mrlmd , I just checked your thread and this might be the cause of your problem too.
Last edited by GCG; Mar 14, 2019 at 11:23 PM.
Drifting
Joined: Jun 2013
Posts: 1,957
Likes: 342
From: Shell Point (Crawfordville) Florida
I was wondering too, if the photosensor fails, if it could totally kill the display, but I haven't found anyone discussing that,
If anyone finds a replacement for that, I would be interested in that too.
One of these days I will finally decide to take my car apart, but I can't believe Trog's persistence in taking one apart three times to try and solve this problem. Hopefully a little solder can cure this, and when the C5 was originally designed I guess nobody thought this would ever fail, or they would not have made it so difficult to access.
If anyone finds a replacement for that, I would be interested in that too.
One of these days I will finally decide to take my car apart, but I can't believe Trog's persistence in taking one apart three times to try and solve this problem. Hopefully a little solder can cure this, and when the C5 was originally designed I guess nobody thought this would ever fail, or they would not have made it so difficult to access.
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Melting Slicks
Joined: Jan 2009
Posts: 3,275
Likes: 739
From: Miami FL
If the original photosensor doesn't have any markings and can't be identified, I'm sure that by experimenting a little something can be found to replace it. After all, it's been replaced by just a jumper... so we know that even with 0 ohms it will work.
Photosensors are not expensive (cents) and could be photoresistors, photodiodes, phototransistors. It would be a matter of finding one of that could provide an appropriate range.
Perhaps destiny chose you to be the one to find it!
Photosensors are not expensive (cents) and could be photoresistors, photodiodes, phototransistors. It would be a matter of finding one of that could provide an appropriate range.
Perhaps destiny chose you to be the one to find it!
Thread Starter
Drifting
Joined: May 2003
Posts: 1,979
Likes: 48
From: Lakeport CA
So... the sensor looked exactly like the photos above. Tested w/ ohm meter, shows change between under my work light & not. Resoldered. No real change. Added some solder to a number of points on the primary circuit board. Although nothing looked suspicious. Capacitors were not swollen or leaking.... All back together & returned to customer. Not sure I really fixed anything... going to text them today & see how it's going. I do believe it is something with the sensor as the display does not go bight/dim after hitting it with a light compared to two other cars I have in shop.... Could be the board as well...
Melting Slicks
Joined: Jan 2009
Posts: 3,275
Likes: 739
From: Miami FL