Rohde & Schwarz UPL Repair - Page 1
Forum section: electronics / repair

author: JimS
author_rank: Contributor
timestamp: May 24, 2021, 08:13:09 am
content: First time I have ever seen this problem.First up, a short background summery on this UPL.When I first turned it on I noticed the fan was a bit loud and made a mental note that it would need replacing.I took a quick glance at the screen and saw that the UPL application was not running.Turned it off and thought, here's another one with a dead hard drive.Having restored a another UPL with a dead drive, I expected it to be a routine repair.A few weeks later I ordered a 512 meg compact flash card and a adapter board.Fired up the UPL and, this time, took a close look at the screen.It looks as if the LCD was rotated 180 left to right.I opened it up so I could check it over, check the motherboard / replace the CMOS battery.I found (4) 1000uF @ 6.3V caps had bulged and 2 had leaked, replacement caps are on order.Once I replace the caps I will continue my troubleshooting.Because all IO (except keyboard) is handled on the main R&S made board.Not sure where this will lead to, but I do have the 2 other UPL's worth of parts to swap for testing(About a year ago took 3 R&S UPL's, working & not working, and made 1 good one out of the 3.)I will post more information as I find out what is going on.

author: tautech
author_rank: Super Contributor
timestamp: May 24, 2021, 08:31:39 am
content: Could it just be simple like the horizontal plate outputs are swapped ?

author: JimS
author_rank: Contributor
timestamp: May 24, 2021, 12:35:23 pm
content: The display is a LCD screen.Lucked out on this one you can see it ok.On the other one I repaired, it was so dim I had to replace the CCFL.

author: JimS
author_rank: Contributor
timestamp: May 26, 2021, 09:56:37 am
content: While I wait on the caps to arrive from Digi-key.I thought I would post some pictures of the inside of the UPL and where the repair is at now.Picture list:MotherboardClose up of blown capsThe dead HDD and it's replacement compact flash card & adapter board.Interconnect riser board on the top main PCB.LCD/VGA chipThey did, what I would call, a ah.. 'unconventional' way of interfacing the mother board to their board.All the I/O and power is routed through one of the motherboard's 16 bit ISA slots.There is a I/O chip that handles all the I/O functions, FDD, HDD & I/O ports.Funny thing, I found the VGA chip on closeout at Jameco for all of $4.95 ea.

author: slbender
author_rank: Regular Contributor
timestamp: May 26, 2021, 04:48:59 pm
content: Quote from: JimS on May 24, 2021, 12:35:23 pmBack not so long ago, on April 26th, 2020, a really nice fellow named Bart, posted on DIYAUDIO that he successfully used a string or two of flat white leds powered from an internal 12 volt line inside the set, to replace the bad CCFL in his UPL's LCD. He also posted Software, DOS, Service Manuals, Installation disks, Many Photos, of his UPL. Look on page 4 for the following Google Drive link: "R&S UPL Audio Analyzer" - in "Home > Forums > Design & Build > Equipment & Tools > Rohde Schwarz R&S UPL Audio Analyzer Renovation." (currently a thread 23 pages long on DIYAUDIO.com)Jim - Since you do get a proper picture on the screen (albeit backwards) I'm not so sure the LCD/VGA chip is bad, maybe some output wire connection related to the LCD input or output signal became reversed?I'm going to see if I can remove the VIA motherboard, to check the CMOS battery (usually its a CR-2032) and also look for any bad/leaking caps, at the same time.Steven

author: YetAnotherTechie
author_rank: Regular Contributor
timestamp: May 26, 2021, 06:07:38 pm
content: Since it's had other upgrades, it's possible that the lcd too was replaced....with the wrong one, a single letter mismatch on the reference can cause this kind of things.

author: JimS
author_rank: Contributor
timestamp: May 27, 2021, 11:41:02 am
content: Thanks for the reminder about the DIYAUDIO.com post.I have the UPL V306 software and MS dos 6.0 and 6.2.When I get to looking closer at the display I will check to see if it has been worked on.At first look over it looked ok.The UPL has been worked on as I found a missing washer on one of the drive mounting screws,And 1 slightly loose and 2 or 3 not fully tightened screws on the VIA board.

author: Mark S
author_rank: Newbie
timestamp: June 22, 2022, 12:03:42 pm
content: Sorry for the Necro here but I have acquired a UPL Diplay is like the OP upside down...,.. VGA out put is normal was a solution found to the display problem? if so would you care to post?RegardsMark S=

author: Mark S
author_rank: Newbie
timestamp: August 24, 2022, 09:20:40 am
content: So from me an update on this one .......I have not yet found the problem however when you apply a little percussive maintenence from above the LCD then the display either flickers or becomes normal.....This is a classic intermittent problem now should I look for the problem or use an ever bigger hammer?Mark S =

author: Mark S
author_rank: Newbie
timestamp: August 30, 2022, 09:08:15 am
content: Last updateTook the front panel off to get to the LCD screen all connections re-seated.Now works just the way it should without the hammer!fixed for me at least and if all fails there is the VGA output.Mark S=