OBC Rev Counter Display Repair
#31
Hi !!!
I have the same problem as mentioned over here. My display becomes erratic with different segments of the display lighting up in a random pattern. Do I have to check Diode 1N4118 or BS170 ???
Thanks!
I have the same problem as mentioned over here. My display becomes erratic with different segments of the display lighting up in a random pattern. Do I have to check Diode 1N4118 or BS170 ???
Thanks!
#32
Hello.
I've just repaired one of those OBDC.
In my case, the guilty was the BS170 transistor. It is a NMOS transistor, not easy to find. The 2N2700, in my opinion, has a too low power dissipation.
So I replaced it with an high-gain NPN generic transistor, a BC3525, and all works fine!
Thanks to all the forum!
I've just repaired one of those OBDC.
In my case, the guilty was the BS170 transistor. It is a NMOS transistor, not easy to find. The 2N2700, in my opinion, has a too low power dissipation.
So I replaced it with an high-gain NPN generic transistor, a BC3525, and all works fine!
Thanks to all the forum!
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abiazis (12-24-2022)
#33
OK I have not got this problem but on looking at my display it appears that the back lighting to the rev counter near the red line is slightly dimmer than the opposite side and the rubber ring had taken on a milky appearance that I wanted to sort.
Out of curiosity I decided to look at how easy the dial is to take out - this is where I encountered an issue!
The glass and black bezel is loose and only appears attached to the bottom section of the dial! I know that if I pull it I will end up pulling off the glass and bevel with inner bezel leaving the dail/unit behind.
On inspection it has obviously been removed before (some marks on outer bezel - perhaps for this fix?) but can't understand how it can have come loose given the DIY disassembly techinque and how the alu bezel is 'crimped' onto the unit. Unless it was not refitted properly.
Has this happened to anyone else and is it possible to buy just the outer bezel?
I anticipate removal will be to take out an adjacent dial and push the rev counter out from the rear?
At present a couple of spots of superglue have stuck it back down - and I'm thinking it if aint broke don't mend it.
Out of curiosity I decided to look at how easy the dial is to take out - this is where I encountered an issue!
The glass and black bezel is loose and only appears attached to the bottom section of the dial! I know that if I pull it I will end up pulling off the glass and bevel with inner bezel leaving the dail/unit behind.
On inspection it has obviously been removed before (some marks on outer bezel - perhaps for this fix?) but can't understand how it can have come loose given the DIY disassembly techinque and how the alu bezel is 'crimped' onto the unit. Unless it was not refitted properly.
Has this happened to anyone else and is it possible to buy just the outer bezel?
I anticipate removal will be to take out an adjacent dial and push the rev counter out from the rear?
At present a couple of spots of superglue have stuck it back down - and I'm thinking it if aint broke don't mend it.
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abiazis (12-24-2022)
#34
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With the best will in the world Bill964s, "OBC backlight repair" photo bears no resemblance to the circuit board I am having problems with on my 993 cabs circuit board, I have renewed the bulbs to no effect any one got any ideas which will help me?
#36
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With the best will in the world Bill964s, "OBC backlight repair" https://rennlist.com/forums/993-foru...-repair-2.html
photo bears no resemblance to the circuit board I am having problems with on my 993 cabs circuit board, i.e There is no transistor to be seen on my board.
I have renewed the bulbs to no effect any one got any ideas that will help me?
photo bears no resemblance to the circuit board I am having problems with on my 993 cabs circuit board, i.e There is no transistor to be seen on my board.
I have renewed the bulbs to no effect any one got any ideas that will help me?
#37
Steerpike,
On latest 993 OBC board, no BS170 transistor.
The fault is due to a burned board track. Have a look on the left top side of your circuit board and let me know is there is a burned point ? the track that usually burn is inside the board, you can check with a light thru the board and you will see the burned cutted track.
You have to rewire with an external 5 cm long cable.
GeD (from France)
On latest 993 OBC board, no BS170 transistor.
The fault is due to a burned board track. Have a look on the left top side of your circuit board and let me know is there is a burned point ? the track that usually burn is inside the board, you can check with a light thru the board and you will see the burned cutted track.
You have to rewire with an external 5 cm long cable.
GeD (from France)
#38
i know this is now an old topic but i have a problem with my display in that when i switch off the car and lock it the display still stays on- just the backlit part, the digits go off.
Any ideas?
Any ideas?
#41
Burning Brakes
Thread Starter
I know it's been a very long time since I stared this thread, and it has been very informative. My backlight is now permanently on, even with the ignition off, and it will not go off even if left over night. Do you think it's the same component that needs replacing, or is it likely to be a different problem?
#42
Rennlist Member
Hi there, yes I would think you have the common transistor problem. It's a 15 minute job to fix.
http://www.bergvillfx.com/obcrepair.html
Cheers,
Tore
http://www.bergvillfx.com/obcrepair.html
Cheers,
Tore
#43
I know it's been a very long time since I stared this thread, and it has been very informative. My backlight is now permanently on, even with the ignition off, and it will not go off even if left over night. Do you think it's the same component that needs replacing, or is it likely to be a different problem?
#45
Three Wheelin'
I'm about to tackle this by following the instructions here: http://www.bergvillfx.com/obcrepair.html
I can source the bulbs through Pelican, but does anybody know where I can find the transistor? I'm having a difficult time finding one online and am seeing prices ranging from $1-100+. There is obviously a difference between the parts I'm finding but I can't differentiate between them myself. Any help would be appreciated!
I can source the bulbs through Pelican, but does anybody know where I can find the transistor? I'm having a difficult time finding one online and am seeing prices ranging from $1-100+. There is obviously a difference between the parts I'm finding but I can't differentiate between them myself. Any help would be appreciated!