DPO7104 blank screen - Page 1
Forum section: electronics / repair

author: JFKamin
author_rank: Newbie
timestamp: January 02, 2024, 02:14:39 pm
content: Hello:I am new here. I see there is a wealth of knowledge on here and hoping I can get some help.I have a Tektronix DPO 7104 what the display is not operating. . I got it for junk because of it. . It works but the screen is blank.When I first got this unit it did not even do what it is doing now so I made some progress. . It would never do anything but operate fans when powered on and the indicator leds for power supply were all good. I checked all power supply outputs and they were all good. It would just sit there blank and none of the front buttons would ever go on . I was told it worked but sat in closet for long time. Then never worked.I first changed the CMOS battery and it began going into full running mode, with blank screen. I dont think it had anything to do with me changing the cmos battery. I think it was because I had to remove one of the SIMM memory cards to change the battery. removing and reinstalling one seemed to get it to boot up. Must have been bad connection. I removed one SIMM again to test theory and it does cause the unit to not boot as before. The BIOS must detect one missing and will not boot.SO now, with the SIMMS installed correctly seated , The screen goes all white when powered on and slowly fades to a subtle hint of backlight.I decided to connect external monitor to upper video port, it did not work, I connected it to the lower VGA port on the side and there is display . It seems the unit is working fine in every way except the front display .It takes a long time for the scope to boot up to full running mode.I believe that the display may be fine , possibly something else is wrong.Ok what I know. When it is up and running. That upper VGA video port does not work, Unless i go into the windows settings for display, and turn on the Dual video mode in the ATI control panel in the Window display control panel . After I do and reset the system, Then the upper VGA port works and only shows The windows OS screen , as if the TEX scope is not even in the system. So the upper video output is different than the lower one. It done not contain Scope date in the video stream.I read in the manual and it states the PCI board merges Computer video data from mother board, with the scope video data from interface board, and sends it out the PCI bus to the LCD. It says that the PCI video out on lower side external connector Im using is the same video output that goes to the LCD front display, IT is a combined video of both the Windows video and scope video. It says the Video data out of the top VGA port on side is PC display data from the Motherboard only. This seems to make sense.BUTThat tends to conflict with other information in the Maintenance manual, because the manual also states that when the front video does not work, it can be the display setting in BIOS is wrong. They say TO connect to the top video side port with an external monitor and set BIOS to PCI output for display.the conflict is , if it is true the side lower PCI VGA output and LCD port from PCI are from the exact same PCI output, then the lower connector side PCI output video and the front screen PCI video being from same place would both not work , if the BIOS PCI is set wrong. Yet I do not see that . I have no LCD video and yet I have full Side PCI lower port video data to the Monitor. so I do not trust this documentation.However, they do say to use the upper video output port on the side to set the BIOS, and that is not working normally, unless I set the ATI to dual video output on in the windows display setting control panel.If that port should be working without that change in widows display settings then there is a problem of some kind.I do have video on the side lower port VGA. If that really is the same as LCD video data port, then I would think the cable is bad or the display internal interface is not operating. Maybe. However the backlighting Does work for display.Also, I have some issues with the tech data being right because Its description of the BIOS menu is wrong.It says if front display is not working, the BIOS may have the video display set to the wrong output in the BIOS. Suggesting it is not set to PCI.It suggests to go into BIOS and set the video out to PCI, but there are two PCI options to select in BIOS. either PCI, or PCIe in the BIOS.I haven't tried PCIe. should I?There is also a description in there to reload BIOS that makes no sense.It Says to load and save optimized defaults for boot loader,then select Y for save and exitBut instructions then say, Boot to update media.That makes no sense to me. There is no boot to update media option.Because when you hit save and exit it just goes to boot, what is this "update media option" ?then it says, select at main menu," install BIOS and LOGO"I have no such option in the BIOS boot list to install BIOS or logo .So the step by step instructions are goofyAnother thing I noticed ,When the unit powers up there is no beeping, but the problem flow chart, in the Maintenace manual states the unit should beep. it even has decision box, did the unit beep Yes no?I wondered if there should be beeping at power up, and there is none.I looked in BIOS and it has audio disabled. Im wondering if this is right?SO I reload BIOS optimized defaults. Yet that option of audio remains disabled after setting BIOS to factory optimal defaults. either it belongs that way or the defaults do not bother with that setting.On the external monitor. connected to lower VGA port on side. as unit is powered on through power on , it is typical PC booting window showing the BIOS loaded its version and the goes to a normal windows boot window, asking if you want to normal boot or Recovery boot. no errors .I Just loads windows, runs it, then opens the Scope application and runs it.I ran Scope diagnostics, which returns no errors, so the scope application apparently has no idea the front screen is not working.Thinking maybe the problem is isolated to the PC based hardware for the display, I tried older windows recoveries, and it made no difference.Im hoping the issue is somewhere in connections. It can't be a Windows or PC based issue, because the bootloader does not even operate the front screen, and BIOS runs the video in native mode long before the PC loads any video drivers. The front screen seems to have no video connection.It is as if there is no actual data going to the front video panel. I checked the ribbon connector from PCI board interface board, they are good. I Removed and reinstalled, no effect.The power supply voltages are all good. There are no red led warnings and the unit is working with external monitor.I checked the touch display and the touch works on the front of the unit. I can control the cursor seen on the external monitor from the touch pad on the scope .. In the window "system" I do have a yellow warning of the ATI WDM RAGE theater Video, not working, It says ATI WDM Rage Theater Video . not operating. error code 10.I can't imagine that this scope LCD would suddenly be not working and need a updated version of the ATI driver because it sat unused for years.anyway I uninstalled and reinstalled the ATI driver, but it made no difference. It is a fairly high version 6.XX .I did notice that BIOS AUDIO is set to DISABLED in the BIOS and it may be why the unit does not beep through startup as the book says it should.It could also be why the system hardware shows ATI is yellow warning, if the BIOS configured the ATI as Audio disabled. the ATI then is partially off.Im sure the ATI controls audio too. I decided to see if AUDIO is enabled in the optimized version of BIOS.when I load the BIOS optimized version, It did not set audio to on, So im confused as to if it should be set on. Its possible the BIOS optimization does not touch that setting, and as a result it is just remains set to disabled . In which case I may need to change it.This unit had a bad CMOS battery , and it is possible the BIOS is corrupted, WHich would be rare since 99.99% of it is as it should be. The only thing I think the battery does is save date and time .I was wondering what BIOS sets a DPO7000 series audio to ?, if someone has one.Also, if the DPO7000 series BIOS should be configured the video out to PCI or PCIe ?If anyone has any ideas on how to test this Video panel to be working can you let me know. I was thinking I could use the scope itself to fix the scope since it does work with external monitor, I should be able to check the Video lines going to the LCD. Does anyone have tips on where to probe those LCD data lines (pins/pads) and what they should look like. ?Even though the Windows system hardware listing shows the ATI WDM has a yellow flag , with code error 10. If I go into the windows control panel and chose to display and then select the hardware tab, it says this device is working normally.This seems to conflict with the system Hardware Yellow flag it is not working.But it could be caused by the fact the system hardware listing flag is based on the WHOLE ATI functionality status, which includes the Sound and Video functionality. The yellow flag here in system could be the result of BIOS setting the audio to disable. leaving the video to function normal. AS a result, maybe the Video control , shows it is working normally but the overall ATi status in system listing states it is not working properly.thanks for your time. Any advice is appreciated.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 02, 2024, 03:11:32 pm
content: 1st reorganize your text, i wont read thatthks it will help YOU

author: coromonadalix
author_rank: Super Contributor
timestamp: January 02, 2024, 03:33:03 pm
content: ok this is a pc at firstyou need the correct settings for the video, if not the lcd scrren size will not be ok and will not boot on the lcd at firstyou need to acess the debug port on the scope, normally seen around the pc and scope backplanes, (normally) its a 10 pin header, but some people had to fiddle some connectionsthis port is the vxwork booting process, you need to see if it is corrupted or bad etc ... 9600, n, 8, 1 in a windows terminal softwareyou may have the mother board battery who went dead AND the NVRAM battery too, if this one dies the scope will not work well, you will need to reconfigure ithttps://www.eevblog.com/forum/repair/tek-dpo7104-recovery-image/https://www.eevblog.com/forum/testgear/tektronix-tds-7404-is-not-booting-up-looking-for-firmware-image/https://www.eevblog.com/forum/testgear/tek-csa7404-repair-project/https://www.eevblog.com/forum/repair/tek-dpo7104-looking-for-flasheeprom-content/read this one 1st for the nvramhttps://xdevs.com/fix/csa7404/

author: coromonadalix
author_rank: Super Contributor
timestamp: January 02, 2024, 05:52:55 pm
content: the sound is the least of your problemsnow find in the bios the video settings : and the lcd is normally set to internal pci not the pciethe tds7k main threadhttps://www.eevblog.com/forum/testgear/tek-csa7404-repair-project/825/before playing with the scope driver side: you need all drivers to be installed and absolutely no exclamation marks in the device manager ....you have video driverstouch panel driverspower pc driverchipsetnetwork ....you need to have a clean vxwork folder on your C: drive and have the vxwork config files, i commented a lot on the last pages of this thread ...

author: JFKamin
author_rank: Newbie
timestamp: January 03, 2024, 01:15:51 pm
content: Im sorry I took so long to reply. I was not aware you replied to post. Im not getting email alerts.Ok Im not aware of second battery on 7104.I did find the CMOS battery I believe on the motherboard. It was a CR2025 I think, and it had a socketed battery holder, easy to change.I did not see another battery.See picture of another board like mine I found online and I marked where the battery is i changed.I think it would be best to start with replacing any other NRAM battery that Im not aware of. Or where it would be. feel free to mark this picture where another battery may be on the mother board.Thanks, you are a big help.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 03, 2024, 04:47:42 pm
content: this is the cmos battery of a motherboard, if this one fail you loos some boot configurations, clock and other settingsit may fail to detect the hard drive or other things, it depends if you have saved a few things by default etc ....

author: d37duck
author_rank: Contributor
timestamp: January 08, 2024, 02:19:18 am
content: Hi JFKamin,I have a DPO7254. It's an early model and has 1 VGA connector from the Intel D945 motherboard on the scope's left side, looking at it from the front. For this reason, I can't picture what you're describing that has two VGA's. Please send us some pictures of your scope and the Tek part numbers of the manuals you described.Regards,

author: JFKamin
author_rank: Newbie
timestamp: January 08, 2024, 03:10:58 am
content: The pictures are attached and a couple screen shots of the maintenance manual. Im beginning to think the display is just gone dead. The side Port to external monitor works fine. the scope works fine too. I still have the yellow flag for the WMB, but It could be that the LCD display handshake is not working and the processor I/O knows the port is not working as a result.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 08, 2024, 03:34:07 am
content: i received some help needed in pm for theses, the previous thread before mine explained a few things correctlyso far in the dpo7k at xdevs once registered, i dont see much/Tektronix/DPO7104/ there is : TekScope_5_3_5_22_Firmware.exe around 1.2 gigs/Tektronix/DPO7KC/ folder with some stuff, 3 big files total of 3 gigs ...but if you need some more, like iso images, there is on xdev's the /Tektronix/VM6000/ and in it /Tektronix/VM6000/backup_iso/ folder who has some 5 parts iso around 3 gig total ??not sure if it can help someone but you need xdev's registration to grab them

author: d37duck
author_rank: Contributor
timestamp: January 08, 2024, 05:52:04 pm
content: Hi JFKamin,Thanks for the references from the Tektronix Service Manual part number 077-0076-10. Anyone interested can go to the Tektronix website and download the complete manual along with many others.I forgot about the other VGA port at the bottom left side of the instrument. Thanks for the picture of your scope, it jogged my memory. I checked functionality of my DPO7254. The output from that port displayed on an external monitor is the same as display on the scopes front panel LCD screen. There is no display from the VGA port on the top left side of the scope (coming from the Intel D945GTP ATX motherboard).Have you trouble shot the LCD display module? There is a driver circuit board with touch screen interface on the pack side the module. The connections are tin plated. They may have oxidized.Regards,

author: JFKamin
author_rank: Newbie
timestamp: January 09, 2024, 09:08:06 pm
content: I can get display from the top side port by simply going into windows Display settings and configuring the ATI to have dual output. Setting output (2) to on. In windows it is normally set to off. Once you set it to on, the Top port will operate after resetting the system. It will only have the Windows related operating system display. This is because according to the theory of operation the PCI interface board takes the motherboard video and merges it with scope video in the ATI sends it out the bottom port and the LCD port. But. This really confuses me because, the motherboard Video has its own xvga port that goes to the top connector and is should not be affected by the setting of the ATI. UNLESS when you enable the ATI in dual mode you are enabling the I/O Buffers to the Motherboard port.I didn't check My display as you ask yet. But I am leaning that there is something wrong in the display itself. I did check the ribbon connector. It is mated fine. If I had a pinout of that ribbon connector, I could create an adapter ribbon that plugs into PCI board there and goes to a VGA D style connector and then connect an external monitor to prove that the board is fine. THen focus just on display

author: JFKamin
author_rank: Newbie
timestamp: January 09, 2024, 09:17:42 pm
content: this is good news about the driver board on back of display and oxidation of connector. I did have either oxidation or mis mated SIMM card at first. The whole thing would not run. Until after I demated the simms and reinstalled. If there was oxidation there then the LCD is likely the same. Thanks

author: JFKamin
author_rank: Newbie
timestamp: January 21, 2024, 10:43:56 pm
content: So I checked ALL connections on back of LCD after removing it, they are good. I noticed that the backlight is working fine. Im thinking That I want to reload the driver for the ATI which has a yellow flag. I will need to figure out how to do that since I dont have it and Im not sure where to get it. I did some reading and if the backlight works it is likely the driver is not working, or the cable is bad from the PCI board to the LCD display, Or the Timing control logic board on back of LCD is bad, or the LCD screen itself is bad. . I wish I had another display to pop in and check if it works. Then I could focus on just that. Does anyone know where I can get a known good driver for this display chip. I read a thread on here where someone did load a new driver on one of these but uis was not clear what he used or where he got it.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 22, 2024, 03:31:22 am
content: maybe theseshttps://www.amd.com/en/support/graphics/legacy-graphics/ati-rage-series/ati-rage-proclick on the + to open downloads

author: JFKamin
author_rank: Newbie
timestamp: February 02, 2024, 10:43:14 pm
content: Update. The display is working.What I learned.The yellow flag in the system hardware for the driver, is in my case related to the driver not being able to work. Not that it was a bad driver. the Driver was simply not working fully because of broken hardware and trying to tell me.The system hardware breaks down of the Display is. The mother board communicated with PCI board. The PCI board has the video interface logic. It talks to the video ports and the monitor. The cable going to the touch control board. The touch control board receives inputs from the touch control glass, but it also is the interface to the LCD Timing control board, and generates the Back light commands to turn on " wake up" . The back light intensity is driven is controlled by the logic board of the front panel controller. The power to the back light is from the Inverter board. The inverter board and the Touch control logic board are on the back of the LCD frame. The Timing control board is under that that on the back of the LCD screen and is not accessible by removing screws. The T&C board controls the display raster. This board needs to complete its handshake to the touch control board, for every screen raster scan or the PCI board video controller will generate a fault, that the T&C board is not responding. The ATI chip on the PCI will keep talking to the VGA port and report the fault to the system Built in test routine. Thats because the ATI interface chip is a dual video controller chip able to talk to two video output ports at the same time. This is why the VGA keeps working when the LCD Display malfunctions. There are four things that can kill a video past the PCI board. They are the Inverter board, the Touch logic board, the Control panel board, and the T&C board, and the LCD panel itself. My problem was the LCD T&C logic board died. The Touch logic was talking to a dead board, and it was not handshaking. This set the yellow flag in the system box on the driver not working correctly. The moral to this story is , it is not always software problem when a yellow flag appears in the system driver status window. My Scope is now working perfectly. Im now looking for a good top blue plastic panel. Mine has a chip on the corner in the back. Id like to fix it.