How to bypass the Sony Betamax SL-C7E timer block?

[Asbestox]

So i have a Sony Betamax SL-C7E that has a broken timer block(it contains boards TM-10, TM-11 and TM-12). Is there a way to bypass it?
Image of the cables, and the connections to the boards i found in the manual.


[Attachment 85919 - Click to enlarge]


[Attachment 85920 - Click to enlarge]

[themaster1]

I don't know much about betamax but on vhs deck (philips and others) the timer chip is linked to a super capacitor. You change it you restore the timer (small and round)

[Asbestox]

Sadly, no. The entire board is broken due to the battery leak, the entire board is missing. Also i dont need the timer, i just need the functionality to playback, fast forward and rewind with audio and video output.

[dellsam34]

Did you try to turn off the timer from the VCR or remote? just a wild guess, I don't know how the timer supposed to work on those old beasts.

[Asbestox]

I sadly dont have a remote. Didnt come with the betamax.

[betwixt]

No guarantees, I don't have the full service manual to check.
Try linking the 'blu' wire on CN7004 to the chassis. If that doesn't work, get hold of a 1K Ohm resistor and use it (with extension wires if needed) between that blue wire and the blue wire on CN7003. That will mimic the timer output signal as low or high level, I have no idea which is on and which is off. It is possible other functions are on the timer board that are necessary for normal operations. Only one way to find out....

Brian.

[Asbestox]

https://archive.org/details/manual_SLC7E_SM_SONY/mode/2up heres the full manual, ill try do what you told me to, thanks!

[Asbestox]

No guarantees, I don't have the full service manual to check.
Try linking the 'blu' wire on CN7004 to the chassis. If that doesn't work, get hold of a 1K Ohm resistor and use it (with extension wires if needed) between that blue wire and the blue wire on CN7003. That will mimic the timer output signal as low or high level, I have no idea which is on and which is off. It is possible other functions are on the timer board that are necessary for normal operations. Only one way to find out....

Brian.

Also how much watts should the resistor be?

[Asbestox]

Sadly the CN7004 bridge didnt work. Ill try tomorrow the resistor one.

[betwixt]

I suggested the 1K resistor because it would offer some protection, not knowing what the signal fed in to. Now I have seen the schematic I think it is safe to directly link it to CN7003 as long as the timer board is not present. The signal feeds the power supply and seems to be a simple "turn on/turn off" control. It is a combination of the manual power switch and the timer output.

Brian.

[Asbestox]

It still doesnt work sadly. I did it, but nothing. Idk whats the problem.

[Asbestox]

Ill check the manual again to check if i missed something

[Asbestox]

I had an idea. What if something else is broken also, but i dont think so, because i checked and all the fuses were ok.

[dellsam34]

I looked through the manual and I could see one pin is going from the timer to the sys control chip, I don't think it's an easy bypass if it's even possible unles you flash the chip to ignore the timer state signal, If you know the signal (frequency, voltage) of that signal when the timer sends it off to the sys chip you could build a small circuit and feed it to that pin, but that requires the timer to be functioning to reverse engineer it. So even with the remote control present you probably have to have the timer fully functioning to turn it off anyway.

Just get a working beta machine, Sony made newer models in the Super Beta format, it may not be easy to score a working one but they do pop up online all the time, At least here in the US.

[Asbestox]

Im from Serbia, so no there arent any betamax machines for sale, the cheapest one is around 30$ and its broken, but its prob the common fuse problem. Im going to buy that one because this one costed only 10$.

[Asbestox]

Idk tho i have a video head broken SL-C30E, can i replace some parts from it to this C7E?

[Asbestox]

Idk if even the SL-C30E has a timer block similar to the C7 one. Heres the manual for the C30E https://elektrotanya.com/sony_sl-c30e_sl-c30ub_sm.pdf/download.html

[Asbestox]

I looked through the manual and I could see one pin is going from the timer to the sys control chip, I don't think it's an easy bypass if it's even possible unles you flash the chip to ignore the timer state signal, If you know the signal (frequency, voltage) of that signal when the timer sends it off to the sys chip you could build a small circuit and feed it to that pin, but that requires the timer to be functioning to reverse engineer it. So even with the remote control present you probably have to have the timer fully functioning to turn it off anyway.

Just get a working beta machine, Sony made newer models in the Super Beta format, it may not be easy to score a working one but they do pop up online all the time, At least here in the US.

Ill try to do it, btw whats the exact pin you were talking about so i can try to do something.

[dellsam34]

You can't, you have to have the system working first, then with an oscilloscope you will study the behavior of that pin and what signals it emits and receives at different functions or stages, then you will design an arduino board to mimic those signals. Without a working times you can't do this.

[Asbestox]

Damn, i have a SL-C30E can i transplant something from it to the SL-C7E(on the SL-C30E the video head is broken)

[Asbestox]

GOOD NEWS I THINK? I just connected the TM-10 board and it works(?) Idk because some lights are on but some are off so idk. the tm11 and 12 boards arent connected due to the connection cables got corroded and fell off.

[Asbestox]

The other parts of the betamax are dead still. Is there a chance that something else is also broken?

[Asbestox]

This is what happens when i connect only the TM-10 board.

[Asbestox]

The betamax is still dead.