Bad coin-in optics boards

[stayouttadabunker]

I have a few of these 3 LED S+ coin-in optics boards that have either
intermittent coin detection or do not detect any coins at all.
Thy are made of actually two boards with a short 4-pin ribbon cable connecting them.
( one's with 3 receiver optics/10-pin header coupled to a back board which has 3 emitter optics)
Does anyone know what component tends to go go bad on them?
Do we have someone that may have some type of diagnostic tool to check these boards?
I have various ASSY NO. boards, most are circa between 1984 to 1995>>>

7530443 (1985) coupled with a (1984) 7530380 emitter board.
7530443 (1985) coupled with a (1984) 7530380 emitter board.
7530480 (1990) coupled with a (1984) 7530380 emitter board.
7530523 (1991) coupled with a (1984) 7530383 emitter board.
7530520 (1991) coupled with a (1984) 7530383 emitter board.
7530643 (1995) coupled with a (1995) 7530650 emitter board.
7530643 (1995) coupled with a (1995) 7530650 emitter board.
7530640 (1995) coupled with a (1995) 7530650 emitter board.

Here are a couple of examples of these coin-in optics boards>>

Click on pics to make them larger and clearer,
You'll notice that there's writing etched in on the ABC optic emitter board
verifying that that particular board has emitter optics>>

  
 

[clongames]

Hello, these generally do not trump case that you them install with the flushed(passionate) machine, which can spoil them.
Those who generally are spoilt are the diodes.
These use the machines poker or slot IGT, I recommend you prove(try) it in a machine of poker, you open the machine, enter to the menu, tests(proofs) of entry, and put a paper(role) of the diameter of the currency, the idea is to simulate the step of the currency, on screen are observed the optical ABC that change from 1 to 0.

[stayouttadabunker]

Thanks,
which "diodes" are the ones that get shot?

How may I test them with a ohm or resistance multimeter?

[clongames]

 :88-If in ohms, the pink ones, they measure high place ohmiaje in a sense and fall in another sense, the blacks measure as a transistor, since they are a photo transistors.
Tomorrow I you bring the correct values of all that they measure.

[stayouttadabunker]

Awesome! I can't wait! 

[clongames]

I wait this one serves graph you

[clongames]

 
DS1, DS2, DS3 measure, discharge in a sense and fall in another sense.
Q2, Q3, Q4, it(he,she) measures in both senses high place ohmiaje.

[stayouttadabunker]

Thank you clongames!


I will test the optics Monday morning!

Thanks again!