Electronics > Repair

R&S SMV03 repair - need help with the handles

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1design:
I acquired a R&S SMV03 signal generator of off ebay, it was listed as powers on but nothing on screen.
I was hoping for a power supply issue, or something down that line. Once the unit arrived, things didn't look good...the handles were removed from the instrument and the calibration stickers covering the rear screws were all broken. Someone has unsuccessfully tried to repair the unit and we all know what that could mean :palm:

Once inside, I saw that all of the screws holding on the main board shield have been unscrewed and a lot of the front panel and LCD screws were missing. :-- The previous attempt was not only unsuccessful but also VERY sloppy.

After probing around the STN LCD PCB, I came to the conclusion that the HW works:

* Turning the main knob triggered data to be sent to the LCD
* All the H and V driver lines were happly bouncing back and fort in a periodic way
* Data was written to the RAM with every button press
* All RAM data/address pins were working
I continued my investigation by removing the STN matrix from the controller and there laid the issue. The ribbon connecting the matrix to the control PCB has deteriorated to the point of only contacting on one line, this was also the only line showing up on the LCD.
After fiddling about and cleaning all the surfaces and re-seating the ribbon multiple times I was able to get 6 lines to work. This showed that the device was actually working, only the LCD was damaged.

Encouraged by my latest find, I attached an SA to the output and low and behold, a signal appeared. This was pretty much spot on at  0dBm, 1GHz. There was a substantial amount of phase noise present, fuelling my concerns about the state of the main bard, since the shield has been removed in the past.

I ordered a new LCD, which is readily available from E-bay, if you don't mint spending some $/€.

After connecting the new LCD I was greeted with the R&S logo and the generator GUI...HURRAH!
The GUI also revealed the source of the excessive carrier noise, both AM and FM modulations were turned on with no signal on the modulation inputs.

So, in summary, I now have a working SMV03. Regarding the missing hardware, I was able to measure the remaining screws and order additional parts to fill in the missing ones.

The only HW I need help with are the handle screws. Does anyone have a piece of R&S gear and would be so king to measure the size and length and tell the type for the handle screws? Thank you!

If you have any questions about the instrument or repair, please feel free to ask.

eurgenca:
Hello.
I have SML03 I think that is the same. If you still need info I can do that for you tomorrow when came in office.

1design:
Hi eurgenca,

thank you! The case is the same for both units as the SMV03 is just an SML03 with added IQ modulation.

eurgenca:
Hello.
Here you go.

prbsrv.ru:
Hello, Eurgenca

I am engaged in the repair of spectrum analyzers Rohde Schwartz, Agilent, Anritsu, Keysight. There are similar bolts for your device

http://www.prbsrv.ru/

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