Finally got my hands on a signal seeker hitachi from a fairlady but when i powered it up, all i got was static.

Pulled off the cover and discovered 3 diodes were toast. Toast as in crumbled into dust.

I was unable to read the values and cannot find a schematic.

I know it's a shot in the dark, but does anyone have one of these that can tell me what color bands are on the diodes?

These are really hard to get, and with my luck,  i probably have the only one in north america

 

It looks to me like the silkscreen printing on the PCB indicate that part is (was) a capacitor (C9), not a diode. Is there a "D?" designation somewhere else close to the part that has turned to dust?

How about the other two? Are they the same? (Do they look like they were once the same?)

The other 2 have the diode symbol on the board. There is not a symbol on the first image i posted with the C9.

I found one partially intact. Pic 3 below.

It also has a R12  next to it so it may have been a resistor. Whatever it was, it glued the 2 cap's together when it melted. Just a big blob.

Edited June 12, 20168 yr by hr369

Nope. You're right. Those are diodes. The R12 is the 47K Ohm resistor by the "R" in R12.

The good news is that at least on two of the three of them, you know the polarity direction because of the silkscreen. The third one down by R12, you would need to know more about the circuit in that area to figure out which way it should go.

So... They're diodes... There are several different type of diodes, but if they are run-of-the-mill generic styles and not something more application specific (like Zeners) you might be able to replace them with something ubiquitous like a 1N4148 or 1N4001.