transistor replacement on spoiler circuit board?
09-20-2010, 01:24 AM
#1
Three Wheelin'
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transistor replacement on spoiler circuit board?
The spoiler on my 89 C4 is not working. On a previous thread, I was able to determine that the transistors on the circuit board in the controller are bad. I've searched the web for replacement parts, but I have not found anyone to provide them yet.
Does anyone know a source for these transistors?
Does anyone know a source for these transistors?
09-24-2010, 01:48 PM
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Three Wheelin'
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Thanks mojo. Maybe I used the wrong terminology, or I just assumed the wrong part, but that is not the part I was asking about.
I thought the transistors were the 2 brass boxes near the corner of the board. I took it to a large electronics supply here and asked the tech if they had any replacement transistors for the board and showed it to him. He focused on the boxes and showed me how there must have been a problem with them at some point in time because the board showed discoloration, which was a sign of excessive heat, at their solder connections. Did he focus on the wrong parts? Are they capacitors and not transistors?
Regardless, in an effort to try to get the right parts, has anyone out there repaired a board with the following spoiler symptoms:
Spoiler rises when key is turned on and stays up continuously thereafter, even when switch is turned to "off" position. Motor seems to be OK as I can power it from an external source through the connector and it works in both up and down directions as the polarity is reversed.
I appreciate any help you can offer.
I thought the transistors were the 2 brass boxes near the corner of the board. I took it to a large electronics supply here and asked the tech if they had any replacement transistors for the board and showed it to him. He focused on the boxes and showed me how there must have been a problem with them at some point in time because the board showed discoloration, which was a sign of excessive heat, at their solder connections. Did he focus on the wrong parts? Are they capacitors and not transistors?
Regardless, in an effort to try to get the right parts, has anyone out there repaired a board with the following spoiler symptoms:
Spoiler rises when key is turned on and stays up continuously thereafter, even when switch is turned to "off" position. Motor seems to be OK as I can power it from an external source through the connector and it works in both up and down directions as the polarity is reversed.
I appreciate any help you can offer.
09-24-2010, 02:15 PM
#6
Rennlist Member
Those two components you mention are the relays>>>>
It sounds like your problem is simply the closed microswitch underneath the spoiler is stuck in the closed position. What happens normally is as the spoiler raises it opens the "closed" microswitch , after the spoiler opens all the way the "open" micro switch shuts off the motor stopping the spoiler. Now if the "closed" microswitch is stuck electrically closed, then the spoiler won't close because it thinks it's allready closed because of the stuck micro switch.
It sounds like your problem is simply the closed microswitch underneath the spoiler is stuck in the closed position. What happens normally is as the spoiler raises it opens the "closed" microswitch , after the spoiler opens all the way the "open" micro switch shuts off the motor stopping the spoiler. Now if the "closed" microswitch is stuck electrically closed, then the spoiler won't close because it thinks it's allready closed because of the stuck micro switch.
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09-25-2010, 10:27 PM
#8
Three Wheelin'
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Well I checked the microswitches and both of them function properly. Must be the board. When the board is plugged in with the spoiler in the down position, the spoiler raises, even with the key off.
Again, I was told on a previous thread that it was one of the transistors on the board. Anyone able to confirm that the component that mojo indicated is the true culprit? I really would appreciate some help on this one. I only had that one semester of physics in high school 40 years ago that covered electronics in a few weeks.
Again, I was told on a previous thread that it was one of the transistors on the board. Anyone able to confirm that the component that mojo indicated is the true culprit? I really would appreciate some help on this one. I only had that one semester of physics in high school 40 years ago that covered electronics in a few weeks.
09-25-2010, 10:29 PM
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Three Wheelin'
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Well I checked the microswitches and both of them function properly. Must be the board. When the board is plugged in with the spoiler in the down position, the spoiler raises, even with the key off.
Again, I was told on a previous thread that it was one of the transistors on the board. Anyone able to confirm that the component that mojo indicated is the true culprit? I really would appreciate some help on this one. I only had that one semester of physics in high school 40 years ago that covered electronics in a few weeks.
Again, I was told on a previous thread that it was one of the transistors on the board. Anyone able to confirm that the component that mojo indicated is the true culprit? I really would appreciate some help on this one. I only had that one semester of physics in high school 40 years ago that covered electronics in a few weeks.
09-28-2010, 08:30 AM
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Burning Brakes
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The transistor can be treated as 2 diodes connected back to back at the base of the transistor. A simple test with an ohm meter (i.e. set on its' lowest resistance setting or better if it has a diode tester) can be performed by connecting one lead from the meter on the base lead of the transistor and the other meter lead on the collector then emiter leads. The meter should indicate a reading in one direction (i.e. typically 0.7) and an infinite reading when the meter leads are swapped. You may be able to measure the transistor in circuit but it will likley need to be removed to get an accurate measurement.
09-28-2010, 11:44 AM
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One more question Darth. Are the base, emiter and collector leads in standard locations, such as base in the center, others to side, or is there a way to determine which is which?
Thanks again for your help. You seem very knowledgeable about electronics.
Thanks again for your help. You seem very knowledgeable about electronics.
09-28-2010, 03:36 PM
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Burning Brakes
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Can you confirm that BC337 is the transistor to test? Are there not two? Sorry can't confirm/remember did some repairs on mine years ago.
Are the base, emiter and collector leads in standard locations - No
is there a way to determine which is which? Google the spec sheet for each transistor - a lead orientation should be available.
Are the base, emiter and collector leads in standard locations - No
is there a way to determine which is which? Google the spec sheet for each transistor - a lead orientation should be available.
09-28-2010, 08:10 PM
#15
Nordschleife Master
