Siglent SGD830

[coerl21]

i received the "overvoltage protection" warning and no output. Having studied the posts on here I have the correct signal up to the relay that switches to the BNC socket.  There is 5v on the coil but no zero volts on the other end. I'm unable to trace the circuitry - is it a multi-layered board?  This signal is from U17 (3095) to K3 relay to K4 relay (if it were energised) to BNC.  It seems to be a permanent 5V feed to the coil. Does it form a collector load of a transistor?  I'm struggling with SMD - it's too small for my eyesight!
Any help would be appreciated.  I will only use it for aligning radios so I only need a modulated sine wave AM/FM.

[tautech]

i received the "overvoltage protection" warning and no output. Having studied the posts on here I have the correct signal up to the relay that switches to the BNC socket.  There is 5v on the coil but no zero volts on the other end. I'm unable to trace the circuitry - is it a multi-layered board?  This signal is from U17 (3095) to K3 relay to K4 relay (if it were energised) to BNC.  It seems to be a permanent 5V feed to the coil. Does it form a collector load of a transistor?  I'm struggling with SMD - it's too small for my eyesight!
Any help would be appreciated.  I will only use it for aligning radios so I only need a modulated sine wave AM/FM.

Welcome to the forum.

It's very possible you will find the answers you need here:
https://www.eevblog.com/forum/repair/help-fixing-siglent-sdg805/

SDG800 and 1000 series thread here:
https://www.eevblog.com/forum/testgear/the-sdg1000-and-sdg800-thread/

[coerl21]

Thank you for the reply.  I have read those posts and I was prepared to replace an op amp and Bob's your uncle;  but the relay to output the desired waveform is not energising although I have a perfect 470khz sine wave which can also be modulated on the contact of the relay. Is something seeing an overvoltage and shutting of the relay for protection?  Selecting a peak to peak voltage of less than 1 volt and I can't seem to find a response anywhere.

 I have discovered that one of the address lines of a MUX has "mush" going into it and mush coming out of a data pin. I would presume that an address line should be 1 or 0 and not have any type of wave function applied to it. So more in hope than anything else I'm awaiting a new ic to replace it.  All of the relays are switched by the zero side of the coil.  I was expecting to find some form of transistor array but couldn't.  It's a pity there isn't a circuit diagram or even a block diagram would be useful. I do flounder without a circuit diagram!