DSO-X 4154A no display - Page 1
Forum section: electronics / repair

author: rtekal
author_rank: Contributor
timestamp: October 10, 2018, 08:45:10 am
content: Hi,I have a Agilent DSO-X 4154 A in which the display is not coming. I have monitored the voltages mentioned in the service manual. The VP25V (Backlight power) and the (VP13VPRB Auto probe power) are not coming. The front panel lights of Ref, Math & Digital glow sequentially and stops there.I tried analyzing the power up process and found that the NCP3064 pin 5 on/off is held low. I am unable to find out the source for this control pin.Anyone who has faced and resolved this problem, please help. I have 2 more MSO's with the same issue.I read in the other forums that Keysight has a service note 3 for this problem, but Keysight has removed that service note. As it is out of warranty, they are charging a bomb to replace the acquisition board.Regards

author: HighVoltage
author_rank: Super Contributor
timestamp: October 10, 2018, 09:43:11 am
content: Did you try to remote access the scope to see is the scope works and it is only the display?How did this problem happen on this one and the other two scopes?

author: CJay
author_rank: Super Contributor
timestamp: October 10, 2018, 12:10:39 pm
content: Connect an external monitor, try to connect remotely to the scope as HighVoltage suggests, try a factory reset if it's possible via the keypad.

author: Pinkus
author_rank: Frequent Contributor
timestamp: October 10, 2018, 01:25:54 pm
content: Quote from: rtekal on October 10, 2018, 08:45:10 amIt looks like, the boot process stops at this point. Thus it would be better to change the title of the thread to "DSO-X 4154A no boot"It would be helpful to see the output at the UART to get an idea at what exact point the boot stops as this might lead to the cause.My DSOX4024A (from January 2013) also recently started to stop booting every 2nd day and it then needs another try, sometimes 2x (off-on) is not enough and it takes several times. Firmware is the latest version. Thus this service note 3 would be of interest for me too. I am wondering if the flash problem also occurs at (maybe only earlier) DSOX4000 series scopes? Maybe Daniel can help?Edit: I also found the thread, where this service note (MSOX4154A-03) was mentioned:https://community.keysight.com/thread/35583Google finds nothing.Does anybody have an idea?Edit2: Did you check the voltage of the battery on the board (visible on the bottom of the first of your pictures)?Edit3: While this is the correct section repair, you would get much more and qualified answers if you would ask this question in the sectiontest equipment. There are many Agilent/Keysight hanging around - and they probably do not look often into the repair section.

author: HighVoltage
author_rank: Super Contributor
timestamp: October 10, 2018, 02:38:24 pm
content: If it really is a boot problem and even better, a NAND corruption problem, contact Keysight first.Even if your scope is out of warranty, Keysight might fix it for free.I just don't know, if the 4000X series scopes also had the boot problem like the 2000X and 3000X scopes had.I just had the problem with a 3000X scope, that was out of warranty and Keysight fixed it within 10 days for free!

author: TheSteve
author_rank: Unknown
timestamp: October 10, 2018, 04:36:17 pm
content: If you want to know what the problem is then connect to the serial header inside and post the output.

author: Samogon
author_rank: Frequent Contributor
timestamp: October 11, 2018, 01:16:34 am
content: rtekalSince you have open unit, can we ask you to make hires pictures of front end both sides. Yes i know you have to remove shielding can. But if you do we will have great opportunity to do 4024A to 4154A mod. That will greatly benefit community.Thank you

author: rtekal
author_rank: Contributor
timestamp: October 11, 2018, 09:54:15 am
content: Quote from: HighVoltage on October 10, 2018, 09:43:11 amIt just did not boot up the next day.

author: rtekal
author_rank: Contributor
timestamp: October 11, 2018, 09:58:26 am
content: Battery is good.Will repost in test equipment .Regards

author: rtekal
author_rank: Contributor
timestamp: October 11, 2018, 10:04:02 am
content: Quote from: HighVoltage on October 10, 2018, 02:38:24 pmThey have stopped free repair / replacement for the 2k / 3k /4k series and that is the reason they removed the service note.

author: Pinkus
author_rank: Frequent Contributor
timestamp: October 11, 2018, 10:04:52 am
content: Did you try to boot (switch off-on) several times in a row? I read somewhere, that it might take 10x and eventually it will boot.

author: Pinkus
author_rank: Frequent Contributor
timestamp: October 11, 2018, 10:06:24 am
content: QuoteYou are kidding, aren't you? Is this official? How do you know?Edit: I chose my DSOX4024a only because Keysight recognized a problem with the DSOX2000/3000 NAND/flash problem and reacted obligingly and user-friendly. This impressed me very much and gave the Keysight brand a massive boost over all other competitors. I am certainly not the only one.Should they just tear it down like that? I can hardly imagine it.

author: rtekal
author_rank: Contributor
timestamp: October 11, 2018, 10:07:39 am
content: Quote from: Samogon on October 11, 2018, 01:16:34 amThe image limit is 1mb, so a hi-res may be tough, but will try it out.

author: rtekal
author_rank: Contributor
timestamp: October 11, 2018, 10:13:03 am
content: Quote from: Pinkus on October 11, 2018, 10:06:24 amHave spoken to Keysight. They will do a free repair only for a continuously restarting instrument, but not for a dead / non booting instrument.

author: TheSteve
author_rank: Unknown
timestamp: October 11, 2018, 04:21:18 pm
content: 95% this is still NAND corruption. If the corruption occurs later in the boot process the scope will restart, if it happens very early in the boot process the scope will hang.The serial port will reveal all.

author: rtekal
author_rank: Contributor
timestamp: November 10, 2018, 10:00:42 am
content: Finally got back to work on this.Captured the data from the serial header as advised, though I am not sure if I have done it as required. Am a novoice at this. Here it goes.1. Connected the USB - Serial adapter to the serial header. The serial header does not go by regular serial port pin outs. Data was at pin 4, ground at pins 9,10. So wired the serial 9 pin connector to the same on serial header end and received at pin 2 at serial converter, ground to pin 5.2. Used Eltima serial port software to capture data. Port settings set at 38400, 8, N,1. Correct me if I have followed the wrong procedure.Am attaching the terminal & line dumps files.Regards

author: TheSteve
author_rank: Unknown
timestamp: November 10, 2018, 10:10:43 am
content: Data rate needs to be 115200.

author: rtekal
author_rank: Contributor
timestamp: November 12, 2018, 05:22:02 am
content: Thanks TheSteveCaptured data @ 115200. Attaching dump & terminal files.Regards

author: TheSteve
author_rank: Unknown
timestamp: November 12, 2018, 06:20:05 am
content: The data is still garbage, you need to use 115200, 8,N,1.

author: rtekal
author_rank: Contributor
timestamp: November 13, 2018, 04:23:55 am
content: Quote from: TheSteve on November 12, 2018, 06:20:05 amI have used the same settings as mentioned.These are the signals I saw on a scope at the serial header of the DSO.Pin 1. +2.7VPin 2. Pulses 0 to -1VPin 3. Pulses 0 to -1VPin 4. Data +3.3V to 0VPin 5. Pulses 0 to -1VPin 6. +3.3VPin 7. Pulses 0 to -0.5VPin 8. Pulses 0 to -0.5VPins 9 & 10 GroundAs said earlier captured the data at pin 4 wrt pin 9.Am I missing something or wrong somewhere?Regards

author: rtekal
author_rank: Contributor
timestamp: November 16, 2018, 04:51:08 am
content: HiMade a new approach to capture the data from the DSO serial header.Got hold of a old PC running XP SP3 with on board COM port. ( All along I was using a USB to Serial adapter as my WIn 10 PC does not have a COM port). Installed PuTTY and connected the serial header data directly to the COM port.Data captured @115200,,8,N,1.The captured is attached. Hope this helps to analyze the problem.Regards

author: TheSteve
author_rank: Unknown
timestamp: November 16, 2018, 05:02:42 am
content: Don't connect a com port direct to the scope!!!The scope needs 0 and 3.3 volt logic levels, the PC will have + 15 and - 15 levels and could easily damage the CPU in the scope.I'm afraid there is no useful data in the log you posted.I haven't seen the inside of a 4000 series scope but assume the pinout will match the 2000/3000https://www.eevblog.com/forum/testgear/dsox2000-and-3000-series-licence-have-anyone-tried-to-hack-that-scope/?action=dlattach;attach=57253;image

author: rtekal
author_rank: Contributor
timestamp: November 17, 2018, 06:25:54 am
content: Hi,The serial header look like this in the 4000 series. The pin outs dont seem to match with the 3000 series.Secondly can I use this process to try to reflash the scope?https://www.eevblog.com/forum/testgear/dsox2000-and-3000-series-licence-have-anyone-tried-to-hack-that-scope/msg322242/#msg322242

author: rtekal
author_rank: Contributor
timestamp: December 06, 2018, 06:06:08 am
content: Hi,Keysight replaced the acquisition board for free, after a reference to a reply in their community forum about service note 3. They handle it on a case by case basis and are highly secretive about it.Could have saved big bucks last year we spent on repairing a MSO4054 which had the same problem.Thanks for all the responses and support.Regards

author: Samogon
author_rank: Frequent Contributor
timestamp: December 06, 2018, 09:20:15 pm
content: No front end pictures for us.