Electronics > Repair
Rohde & Schwarz UPV Audio Analyzer - teardown and repair
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DaJMasta:
I wonder if the SP3 issue is related to it being XP embedded - maybe there's stuff it's trying to patch that just isn't present in the embedded configuration used.  Interesting that regular old XP doesn't work, do you think it's something like boot write protection being enabled in bios?


I think I sort of may have done that with my AMU transplant, the first testing was done using the AMU drive's image, since it was an SATA based board and slipstreaming SATA drivers into an XP installation was something I remember was annoying years ago.  Worked fine for me, though it does leave you with the wrong programming in the front panel decoder, so you'd have to use something like the script I used to translate it into normal UPV front panel inputs.  If I'm remembering right, I found out after making this post that there was one or two buttons mapped wrong - I built the table off what the keystrokes described in the manual were listed as, but it turns out at least one of those keys actually has a different keystroke equivalent to what the manual claims.  It's a whole thing to get into, but it was eventually successful for me.

Having the AMU was great for me, I used the motherboard in a UPV and eventually the front panel assembly in an SMJ and the price of the full, working AMU was like $300 or something silly since they're not in demand as somewhat old baseband generators.
LoTech:
it could be old buggy embeded XP or operator error ...do not know yet, but it is frustrating as hell  |O

on the FMR9 subjet,
did you happen to have a photo of the FMR9 board from the AMU?
Also, all FMR9 units I see, have a Celeron processor. None have a Core2Solo so I guess not all FRM9 boards are created equal.
WD40:
Hello All,

I have a pair of faulty UPVs here. I've sent another UPV off to R+S before (R+S UK send them to Munich for all repair work), and my wallet still hasn't gotten over the experience. I'm thinking that there's a good chance I'll be able to cobble together a good UPV out of the pair by swapping boards, which will leave me with one that has a plethora of issues. However, before I do this, I'd like to see if anyone here's got any suggestions:

i) UPV A. When we got this it did nothing at all on power up. I managed to find a dead SMD 2A fuse on the linear PSU PCB, that feeds the SMPS. I changed this, but also found a very bizarre fault: the 3.96mm Molex that feeds AC to the SMPS after the fuse was missing pins...like someone had removed it, damaged the pins, but not put it back together. I replaced the pins. Now, on power on, the CPU fan spins, the HD spins, and it gives a loud bleep - just like our working UPV. However, this is where it ends. There are no LEDs coming on, bar the DVD-ROM, which won't open, but light up if you press the button. The large fan doesn't spin, nor does the rear one.

Am wondering if the SMPS still has an issue...or something that's powered by it has a problem. Why did the 2A fuse go in the first place? Did it happen with the initial fault, or could it be the result of a botched repair attempt, when the Molex got damaged? And if the fuse did go without human help, then why? Was something loading the SMPS to do this? If the SMPS works now, why isn't it loading it now? (hopefully not because it's gone completely open circuit and is deaded).

If anyone has a suggestion for where to look next it would be appreciated.

UPV B: this one turns on and the oscillator section works (although has 3dB more THD+N than our working UPV, whether B1 engaged or not). If you look at the live FFT, there is no test tone showing, whether it's set to external input or internal generator loop-back. There is a pronounced bump in the mains region, suggesting PSU noise, which could explain why the oscillator has higher THD+D than our good UPV. It sort of looks like it's monitoring something, as if the A-D stage is working, but it's noisy. I'm not hearing the autoranging relays click.... My initial thought was that the protection bulbs had blown, but it was easy to check that they are not.

So, it would appear that the fault on UPV B is on the analogue board... One would like to hope this can easily be fixed at board level, as it must be by far the most expensive assembly in a UPV....

The obvious thing to do it to take the analogue board out of UPV A and transplant to B. Next step would be to change the caps in its PSU and see if the THD+N improves. The THD+N increase is symmetrical between output channels on the oscilator... The 3dB increase is same whether B1 or standard oscillator.

If we transplant the analogue board, this will leave us with a right basketcase UPV...which makes me think that maybe we should try and fix them one by one... R+S offer a 'fixed price repair' scheme, which I've used before ($$$). We could consolidate A into B, and send them A once my lottery win comes through. The total price will likely be what a UPV might cost in working condition, but unlike one from Ebay ours will be certified.

NB - for anyone considering buying a UPV off Ebay, be aware that *very* few sellers will likely know how to test it. They will likely turn it on and classify it as working if it boots. Unless you've used one in an audio environment, you probably won't have a clue how to test it. The last UPV I got was classified as working, yet the inputs do nothing and it shows dots where it ought to show numbers.... Caveat emptor - as I have found out!
WD40:
Update:

Having decided that the fault in UPV B was most likely the analogue board, I decided to take a punt and swap the analogue board out of UPV A. This made the LF bump on the FFT disappear, to make the noise trace look akin to a working UPV. However, regardless of source, internal loop-back sig-gen or XLR, there was no signal registering still. I then decided that the issue must be the DSP board, so I took this out of UPV A - but got the same behaviour... This makes no sense to me, as a UPV is essentially 3 boards: CPU Board (FMR 6 in both of these), DSP Board, and Analogue Board (the rest of it is pretty generic). The relays click when I alter any input selection options, and everything behaves as it ought to - apart from the lack of signal.

The extra 3db of THD+N was not cured with the new analogue board... These machines were likely powered on 24/7 for years, so am wondering if the electrolytics in the PSU could do with changing. THD+N increase is equal on either channel.

If I've changed the analogue board - and DSP board - what on earth could the issue be? Front panel controls all work on point.

Out of interest: I took the bulbs out and measured the DCR: 300R.
LoTech:
@dajmasta,

I am tired of the first version firmware of my UPV unit and the inability to upgrade so a bit the bullet and bought a AMU200 with a FRM9 board and I am about to follow your footsteps with the conversion.

re: "...If I'm remembering right, I found out after making this post that there was one or two buttons mapped wrong - I built the table off what the keystrokes described in the manual were listed as, but it turns out at least one of those keys actually has a different keystroke equivalent to what the manual claims.  It's a whole thing to get into, but it was eventually successful for me...."

Do you recall which were the additional keys that did not work?

Many thanks in advance!
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