Sequential turn signal help

[corygoodman838]

Hi everyone,

They are supposed to be operated on a variable flasher unit so that the sequential sequence finishes before it resets it.
99% of the time they operate as a on/off light. Every now and then I can get one or two sequential sequences out of it. which leads me to believe it's an electrical problem.

Could anyone give me some pointers on where to start? I have some basic skills so have no problem testing , removing and soldering components back in.

second hand units, both left and right act the same. unknown brand.

 

[crutschow]

Without a schematic of the circuit it's difficult to suggest a course of action.

 

[audioguru]

The part number of the IC is removed.

 

[AnalogKid]

maybe not. Close-up photo of the IC - ?

Photo of the bottom side of the board - ?

ak

 

[Buk]

The part number of the IC is removed.

It's still there, but too little contrast to do anything with it. Maybe "5093" at the bottom?

 

[rjenkinsgb]

That IC looks as if the number may be covered by ink, rather than ground off?
Can you try wiping it with alcohol or acetone / nail varnish remover?

 

[danadak]

5093 maybe date code, week 50 year 1993....


Regards, Dana.

 

[Nigel Goodwin]

That IC looks as if the number may be covered by ink, rather than ground off?
Can you try wiping it with alcohol or acetone / nail varnish remover?

I would suggest it's possibly covered in varnish, in order to give it a degree of water proofing.

 

[rjenkinsgb]

Looking again, the socket connections around the IC pins are also showing what looks like green corrosion.
Cleaning them may help?

I don't think there would be any varnish on a socketed component; too likley to creep and mess up the connections.
Also, on the top surface the markings appear to be showing as depressions rather than different colour, suggesting ink or similar rather than a protective layer

 

[Nigel Goodwin]

Looking again, the socket connections around the IC pins are also showing what looks like green corrosion.
Cleaning them may help?

I don't think there would be any varnish on a socketed component; too likley to creep and mess up the connections.
Also, on the top surface the markings appear to be showing as depressions rather than different colour, suggesting ink or similar rather than a protective layer

I would suggest they perhaps simply sprayed the entire board.