PCB Parts ID Help - wild animals on the loose...

johnvv

Member
Joined
Jul 10, 2006
Messages
301
Reaction score
1
Location
Sacramento, California
Looking for some remedial help on PCB parts ID for my Wild Kingdom EM gun game. I've attached two pics of the PCB in questions and a pic of the scanned schematic area for the PCB.

This board controls the left and right speed of the animals (via the 5 POTs) as they roam the African Savannah. After looking at this board with a friend, it looks like a number of the original parts have been replaced and that the replacement parts are now bad or simply wrong. I'm not sure if the two red wires on the back of the PCB are original or not - I suspect not.

At this point, I'd like to ID all the parts on this board and see about getting replacements as part of the repair effort. I suspect the POTs are okay, but the diodes and transistor are bad or have wrong values. I thought I could read the schematics and figure out what parts I need, but I can't. So, any help would be very much appreciated and you might save some animals lives by allowing them to move faster and avoid the hunters.

Top of PCB 549-914 Motor Speed Control

picture.php


Bottom of PCB 549-914 Motor Speed Control

picture.php


I think the following parts may work for replacing the diodes (which ones?) and the transistor, per a suggestion from a friend. Any clarification on these would be appreciated:

Diode Replacement

Transistor Replacement (I am told that jumpers will be needed to get this modern part into circuit)

As I mentioned, I can't correctly read the schematics and ID the parts. The schematics are the best reference for the correct parts given that some original parts were replaced with the incorrect parts that are now on the board. Simple explanations of which parts are needed and where they go would be most helpful. I am at least skilled enough to remove and solder new parts.

Thanks in advance for any help.
 

Attachments

  • WK_Top.jpg
    WK_Top.jpg
    93.3 KB · Views: 14
  • WK_Bottom.jpg
    WK_Bottom.jpg
    96.6 KB · Views: 12
  • WK_schematic.jpg
    WK_schematic.jpg
    93.4 KB · Views: 15
I'd resolder that raised leg and remove each component from the circuit to test individually. This will also give you a chance to repair the solder mess on the board. Most of those components can be tested easily enough.

Also, are you sure there isn't a revision to the print? Your board doesn't appear to match the drawing.
 
The raised center legs shouldn't matter... in those packages, they're normally connected to the metal 'paddle', so the connectivity is being made through the screw that holds the transistor to the board...

...but it's worth ohming out from the center pin to the trace on the back of the board just to be sure.
 
...are you sure there isn't a revision to the print? Your board doesn't appear to match the drawing.

Yes, thanks for pointing that out. After looking, and understanding, the schematics a bit more, the first schematic I posted is for the left side of the board (target control). Attached is the schematic for the right side of the board (hunter control).

Below it the rest of the schematics for the board:

picture.php


I believe that the parts on the right side of the board, covered by this schematic, are all original and have not be modified as was done to the left side of the board.
 

Attachments

  • WK_schematic_2.jpg
    WK_schematic_2.jpg
    92.2 KB · Views: 2
Last edited:
The repalcement parts are likely acceptable replacements. The look (and size) of many of these parts have changed substantially over time. The best thing to do to verify the parts is a part number search (I prefer Mouser). The list of parts generated from the search will be acceptable substitutes.

For instance: you need 5 1N5624 diodes for the circuit. The part number I pulled directly from your drawing.
 
The odd symbols are prob throwing you off a bit too...

The 2n4871 is a thyristor although it's drawn more like an old-style NFET.

The (2s)c106b1 is drawn like a n-type JFET, but I can't find any datasheet for it.
 
The odd symbols are prob throwing you off a bit too...

The 2n4871 is a thyristor although it's drawn more like an old-style NFET.

The (2s)c106b1 is drawn like a n-type JFET, but I can't find any datasheet for it.

I recognized the C106B part number and realized that it's an SCR that has just been drawn weird. The C106B is the same SCR used on a myriad of older Bally/Stern pinball Solenoid Driver boards.
200V, 4A sensitive gate.
The C106B is the TO-202 package with the center lead cut. Although the TO-202 isn't real popular anymore, they are still available. Easiest to find version is the T106B1 at less than a buck apiece.

Ed
 
Back
Top Bottom