Dead 1984 Curtis Mathes
 

Hello,

I am new to this group, but I'm a member of AudioKarma.

Mom's 84 CM acts like its dead, no power, no clock, ect.

model j2562rd chassis c84-4

I have taken the back off, there is not much to these ss units.
Fuses are good.

Are manuals or schematics available anywhere?
I would like to get it running instead of it just taking up floor space.

Thanks,

Greg
Winston Salem, NC

could be a number of things. bad switch, bad varistor, wiring, diode, solder joints, power cord, circuit breaker(if it has one) etc etc. Sams should have service info

if you find any cm schematics let me know too please, i have a 1982 25" combo i really need the am/fm stereo cassett player w/8 trk schematic for it. one of the speaker output channels is melted cant really make out what was all there ,you can tell they must of had a update in the factory to it, they soldered a extra 4700 ohm 1/4 resister to one of the output transisters .

Unfortunately, the model number does not show up in the sam's index. You might have to find an original CM service manual; and, that may be hard to do.

I assume this set uses a remote control and push button tuning. If that's the case, the problem could be in the tuner control circuitry. It would be a lot easier if you had a schematic; but, the first thing you need to do is confirm stand-by voltage. There needs to be stand-by voltage for the microprocessor and for the relay coil. One thing you could do is jump the contacts of the power relay. If the main chassis comes to life, that pretty much points you to the stand-by/tuner control area. If the chassis is still dead, there will likely be trouble on the chassis.

I have a mid 80s c-m combo,and the tv chassis was made by nec.Yours probably was too.I have never found a schematic,but maybe you will have better luck.

yea theres that small electrolytic cap in the standby that would always go bad. Seems like it was a 47uf at 160volts or something like that. Seems like that was an issue lots of the time.
without a sams your gonna just have to trace it.

It's a little alive...:banana:

I have some of the display working, just the am/pm on at the same time


I removed the delay line circuit and jumped the 3 contacts. AM on the display came on, replaced the delay line circuit, plugged tv back up and pm came on too.:yes::yes:

Nothing else works.....:no::no:

Enclosed is a pic of the display and delay circuit.

I was trying to check voltage at the fuse near the power cord, and the tv came on!!
It ran for 30 minutes or so.
Before I could get the cable hooked up it went off. Dang...

Now only the am lights up on the display.

To be continued...

Check all your solder joints

I decided to remove the tuner and found something interesting, there are two areas that are darked or black, a short? Area includes 2 transistors, caps, and resistors.

I am glad all the cables are labeled by CM.

I removed 7 caps and tested them.
6 read well below the stated values and were falling continuously with the meter on.
Guess those are bad.

To bed I go.

Replace those caps and it might work.

That's my plan.:yes:

VFD display
 

Helloo...I'm new here and didn't know how to create a new thread....so I wrote here......my problem is......:
I have a vfd display taken from an Akai cs-m02.....I know it works fine...but I want to power it up and mount it on the line out of my pc....the thing is I don't know how to wire it up....,what voltage needs..nothing...can anyone hepl me??thanks....I added some pics....

It's alive....:banana::banana::banana::banana::banana:: banana:


Changed most of the caps in the tuner module, clock works, remote works,
have sound and a very crappy picture....:D

I did this without a schematic.

Am I that good? (NO) or is replacing caps and resistors are not that hard?

In the last 2 years I have rebuilt 6 tube amps. (Caps and resistors.)

I still am going to check over the main board.

Time for bed...