CED VideoDisc and Player Discussion

[jsdspif]

Sorry about the "ask me what time it is and I'll tell you how to build a watch"... i have a sgt200 it was working fine but the switch for channel 3 or 4 seemed dirty so I removed the sw4000 stereo board and unplugged three plugs from it so I could remove the other large board underneath to flip it over and take the cover off the rf modulator (or whatever it is) so I could spray some cleaner on the 3 4 selector switch. I also did the other switch in there that either outputs the ced signal or just lets the antenna input thru. I then put things back together and I now have no audio. Not knowing what to do next I opened up a sgt250 to test it and it also has no audio. It's the first test of this unit. I wanted to try the sgt200 stereo board in the sgt250. They are both pw4000 and the other numbers on there (such as 2831402-9) on one board is 2831402-7 on the other. The one thing that concerns me the center plug on the sgt200 is j2 and it's labeled 1-gnd, 2-s1, and 4-+15v however that plug only has 1 wire to it the wire at 2-s1. On the sgt250 however it has all 3 wires going to it, so I don't know if I can safely swap the 2 boards.
Or, in a nutshell, I have 2 units with no audio and am not sure where to start looking for the problem. I have the service manuals for the sjt series but none for the sgt. So if someone knows if I could safely swap boards or has advice what to start looking for have at it. Thank you in advance.

[jsdspif]

just to add to this. I am concentrating my efforts now on the sgt200 which was playing a mono disc before I monkeyed with pw4000 stereo board and the pw300 signal board.
I have no audio from the rca jacks or the coax cable output. I tried a stereo disc in it and the stereo indicator does not light. I mention that because I tried the stereo disc in the sgt250 and the stereo light lights and I get some stereo audio. If I switch the audio switch in back I get mono sound at the proper volume from the rca jacks so a portion of that one is working but a mono disc in the sgt250 is still silent.
I thought at this point I'll just start with the stereo board on the sgt200 and just start checking voltages that are shown on the schematic and see if that turns something up.
like I said, at this time I'm just going to work on the sgt200 and see what I can find

[jsdspif]

I now have mono sound on the sgt200. I had signal from the arm output to pin 3 of U3601 and U3601 was getting power at pin 14, but pins 1, 2 and 3 showed no voltage when they should have had 3.3 volts. So I removed U3601 and installed a socket for it and inserted a new U3601 and I now have mono sound at the normal level, but I have no stereo sound . Or at least I don't think it's in stereo because my stereo light is not lighting. So I'm going to check out U4101 on the stereo 4000 board.

[jsdspif]

U4101 was pretty much the same scenario as U3601. No voltage at pins 1,2, or 3 and the some of the other pins voltages weren't close, so I pulled that out, put in a socket and installed a new U4101 and the stereo light now lights and I can hear the difference in stereo and mono. Only thing I just thought of.... I haven't played a mono disc in it only stereo. Mono disc plays ok also. I'm going to adjust what I can. Some adjustments may need to use a stereo test disc (which I don't have) but I do have the mono test disc so I can at least do the mono adjustments and what ever I can on the stereo end of it. If I can get the adjustments done and get it back together and it still is working I can declare the sgt200 officially repaired.

[digicube]

Where did you source your parts?

[jsdspif]

CEDatum,just send him an email for prices