Teardown & Repair of a SRS DS345 30MHz Synthesized Function Generator

[Hugoneus]

You can watch the video here: [30 Minutes]
youtu.be/SKUT11VDuXc

More videos at The Signal Path:
www.TheSignalPath.com

[Arjan Emm]

Hello Shahriar,
thanks for the great videos i watch them all the time.

I noticed something in your video about the sync cpr error. It might not be a level problem, but actually a synchronization error between the sync and function outputs.
At 4:40, after the generator started up without error, the scoop shows the two outputs perfectly in phase/sync. The zero crossings line up nicely.
At 6:14 the sync out put is slightly ahead of function output. This is only a little bit before you turn the generator off and on and the error shows the first time.
At 7:38 and 8:24 with the error the sync is delayed compared to the function output. After fiddling with the pot the error disappeared and at 18:51  the two outputs are perfectly aligned again.

[Hugoneus]

Hello Shahriar,
thanks for the great videos i watch them all the time.

I noticed something in your video about the sync cpr error. It might not be a level problem, but actually a synchronization error between the sync and function outputs.
At 4:40, after the generator started up without error, the scoop shows the two outputs perfectly in phase/sync. The zero crossings line up nicely.
At 6:14 the sync out put is slightly ahead of function output. This is only a little bit before you turn the generator off and on and the error shows the first time.
At 7:38 and 8:24 with the error the sync is delayed compared to the function output. After fiddling with the pot the error disappeared and at 18:51  the two outputs are perfectly aligned again.

Interesting! Thanks.

[bitseeker]

Thanks, Shahriar. That was a fun puzzle.

I wonder what that long bodge resistor(?) is about on the upper PCB.

[Hugoneus]

Thanks, Shahriar. That was a fun puzzle.

I wonder what that long bodge resistor(?) is about on the upper PCB.

Yeah, not a pretty sight! Seems to go to the ribbon cable.