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Title: DSO5102P Rotary knobs not working [Print this page]
Author: BeanieBob    Time: 2020-4-5 20:05
Title: DSO5102P Rotary knobs not working


Hi All.

My oscilloscope's front panel was working perfectly before but now is giving me issues.
It is a Hantek DSO5102P and I got it only two years ago through Amazon.

* NONE of the rotary knobs on the front panel work
* All the push buttons work including AutoSet EXCEPT  
       Trigger buttons which have responded for a time with the incorrect action
       but appears to be working now.

  I HAVE ALREADY
    * Re-seated the cable at both ends that joins keyboard PCB
    * Performed firmware update
    * Connected from oscilloscope rear USB to PC and can confirm that through the
       PC software it is possible to perform the rotary actions such as Volts/Div setting.

Technically I think the unit is still in warranty - but presume this involves a lot of trouble.
  I would appreciate any help if you have any direction on how I should try to
  get the unit working again,


many thanks in advance







Author: wangshuang    Time: 2020-4-7 16:37
Please contact your local agent for a new keyboard.
Author: BeanieBob    Time: 2020-4-7 19:13
Thank you wangshuang - but I cannot find a local agent to supply the PCB. Can you please advise who is the agent to supply parts for UK/Ireland, or even Europe. Where can I source this part without it costing more than a new oscilloscope? Please advise?

  If possible, can you please advise which parts on the board are likely to fail - I don't mind repairing myself. Thank You :-)
  ( I have repaired other boards in the past and learnt that the same parts fail again and again )

Author: wangshuang    Time: 2020-4-8 09:43
Please perform "Default Setup" to see if it can recover normal.
Author: BeanieBob    Time: 2020-4-8 22:23
Thanks wangshuang,
But after performing Default Setup the problem is the same - rotary knobs still not working.

Please can you get some feedback from your technical team - what components normally fail on the
keyboard PCB so I can try to repair. Or where I can get a replacement keyboard PCB at reasonable cost.
( You appear to be sure it is this PCB, and not main control board )   

It is very difficult to use the equipment in this state. Any help is appreciated - including
further diagnostic suggestions - although i do not have another oscilloscope.

Thanks.


  
Author: wangshuang    Time: 2020-4-9 14:39
Ok, Please give me the serial number, which is behind the stand.
Author: BeanieBob    Time: 2020-4-9 21:20
Thanks wangshuang.
I have sent you serial number by private message
Author: BeanieBob    Time: 2020-4-17 07:46
Hi wangshuang.

I have sent you serial number by private message and I am waiting for your
reply from last week. Can you advise if there is an easy repair for this or
do i need to follow up on the warranty.

thanks.

Author: yomeromex    Time: 2020-6-2 08:46
Hello, I have exactly the same issue, my oscilloscope is two years old but with very few use, after 3 months without use it now it is failing, I will aprecciate for your help to solve this issue, Thanks

Author: Dadhyo    Time: 2020-6-10 04:05
Hello all,
I have exactly the same problem with a dso5202p. All rotating buttons have no effect as if they were not connected. I cleaned the wires, but nothing has to change. If anyone has a solution because apparently this outage is recurring on the DSOs. Thank you
Author: olrn    Time: 2020-6-10 22:00
Hello,
I have the exact same issue on my dso5202p. It is very little used. Tried re-conneting the keyboard cable but the issue remaings.
The seller would'nt help me.  How do i fix this?
Author: wangshuang    Time: 2020-6-12 09:05
BeanieBob replied at 2020-4-17 07:46
Hi wangshuang.

I have sent you serial number by private message and I am waiting for your

Sorry for the late reply, but i didn't receive your email. My address is wangshuang@hantek.com
Author: wangshuang    Time: 2020-6-12 09:10
Dadhyo replied at 2020-6-10 04:05
Hello all,
I have exactly the same problem with a dso5202p. All rotating buttons have no effect as i ...

Please perform self-calibration, after that, is there an error code pop up?
Author: wangshuang    Time: 2020-6-12 09:13
yomeromex replied at 2020-6-2 08:46
Hello, I have exactly the same issue, my oscilloscope is two years old but with very few use, after  ...

Please describe the failing problem, or take a video to me to check it.
Author: olrn    Time: 2020-6-13 22:59
Hello.
I also have this issue. The scope is 1,5y old and is very little used. Re-connecting the keyboard cable did nothing.
Please advise how to solve this.
Author: wangshuang    Time: 2020-7-8 14:51
BeanieBob replied at 2020-4-17 07:46
Hi wangshuang.

I have sent you serial number by private message and I am waiting for your

It is recommended to check this relay.
Author: wangshuang    Time: 2020-7-8 14:58
yomeromex replied at 2020-6-2 08:46
Hello, I have exactly the same issue, my oscilloscope is two years old but with very few use, after  ...

It is recommended to check the relay.
Author: wangshuang    Time: 2020-7-8 14:59
olrn replied at 2020-6-10 22:00
Hello,
I have the exact same issue on my dso5202p. It is very little used. Tried re-conneting the ke ...

It is recommended to check the relay.
Author: OASJ2YSeeEhBQo1    Time: 2020-7-9 00:38
Edited by OASJ2YSeeEhBQo1 at 2020-7-17 08:35

Check this thread on EEVblog, someone had a similar problem and fix it by re-soldering some ICs on the keypad board: https://www.eevblog.com/forum/testgear/hantek-dso5102p-(5202p-firmware)-stuck-on-auto-set/
Author: don.r    Time: 2020-7-9 06:50
Problem is U2 on front panel board. Try reflowing decoupling caps on both 74HC4051 mux/demux chips and pins 1 and 2 of U2 (rotary encoder signal pins). My scope DSO5102P now works (mostly).

Author: JIN64    Time: 2020-7-13 22:11
OASJ2YSeeEhBQo1 replied at 2020-7-9 00:38
Check this thread on EEVblog, someone had a similar problem and fix it by re-soldering some ICs on t ...

The link does not work.
Author: OASJ2YSeeEhBQo1    Time: 2020-7-17 08:37
JIN64 replied at 2020-7-13 22:11
The link does not work.

Ok, I've fixed the link so you can simple click on that since copying the string and paste it on the address bar of your browser seems to hard.
Author: Shoey    Time: 2020-8-13 20:41
Has anyone else been able to fix this fault? Seems to be a recurring issue, several threads about this.
I have so far tried:

Default setup
firmware update
self calibration
checked ribbon cable connection at keyboard PCB and motherboard
reflowed decoupling caps
reflowed ribbon connector on PCB
reflowed and later replaced U1, U2, and U3. (74HC393 and 2 x 74HC4051)
checked relay as previously suggested. Actuating fine and connections are good.
all diodes from rotary encoders fine.

3.2V to keyboard PCB from ribbon cable.

None of these steps have corrected the fault. As others have described: all push buttons respond fine, but no response at all from turning any rotary encoder.

Any suggestions on fixes, measurements?
Author: user567121    Time: 2020-8-23 23:28
Edited by user567121 at 2020-8-23 23:31
Shoey replied at 2020-8-13 20:41
Has anyone else been able to fix this fault? Seems to be a recurring issue, several threads about th ...

Hi all, any news on the rotary knob problem?? i got a dso5102p which was barely ever used and now i got no working knobs, sometimes just sumtimes one or two knobs (ChA or trigger) are working a bit but not accurate. Second issue i have is that i cannot update firmware since recent version from their page is not accepted. Error: 0xfe
my versions are sw: 3.40.0(180120.0) and hw: 1010xffff8108

Author: wangshuang    Time: 2020-8-24 11:51
user567121 replied at 2020-8-23 23:28
Hi all, any news on the rotary knob problem?? i got a dso5102p which was barely ever used and now i ...

Please refer to these posts to solve your mentioned problem:
https://www.eediscuss.com/forum. ... &extra=page%3D1
https://www.eediscuss.com/forum. ... id=14945&extra=

Author: user567121    Time: 2020-9-6 18:30
Edited by user567121 at 2020-9-6 18:36

post deleted

Author: user567121    Time: 2020-9-6 18:31
Edited by user567121 at 2020-9-6 18:36

post deleted

Author: user567121    Time: 2020-9-6 18:32
Edited by user567121 at 2020-9-7 02:37

Thank you, i solved the usb format problem, the new firmware runs ok, the self calibration passes without errors (most of the time) BUT the knob problem still exists, knobs rotation works ~ 5% of the time, it doesn't feel like a bad contact
btw, i tried it multiple times to trigger the cause like a bad contact on the keyboard or bad connecteion on the cable, i have reflowed almost any solder point of any large part like mentioned on the U1 ic and more. The problem behaviour is still 100% the same (my greater fear was it could fail complete but the soldering was lucky)
What could be the cause? Interferences? They work just to fail seconds later without rebooting or barely touching it... I can't look it's own signals with only one scope.. Any Ideas?
Are there spare parts availible for a good price? Frontpanel/cable?
thank you very much for any help



SORRY for tripple-posting... site was stuck in loading





Author: wangshuang    Time: 2020-9-8 15:59
user567121 replied at 2020-9-6 18:32
Thank you, i solved the usb format problem, the new firmware runs ok, the self calibration passes wi ...

You can contact seller for a new keyboard.
Author: user567121    Time: 2020-9-12 02:10
Edited by user567121 at 2020-9-14 06:16
wangshuang replied at 2020-9-8 15:59
You can contact seller for a new keyboard.

he may be dissapeared since his ebay shop is empty he is gone i guess in my case, anyone else supplying spare parts?

Author: Juluya24@gmail.com    Time: 2020-9-25 10:15
Tengo exactamente el mismo problema alguien ha podido resolverlo
Author: Znida    Time: 2020-10-10 17:00
I fixed it. I desoldered all the diodes to the knobs and added them back one by one. It was a faulty trigger level knob. I unsoldered the knob and took it apart. It seemed ok. I put it back and now it is working again.

I wrote this here so If someone else will have the same problem. Unsolder all diodes and put them back one by one and test the knob that have the diodes back. It will stop working and you will know which one is it.  
Author: ying    Time: 2020-10-12 09:54
Znida replied at 2020-10-10 17:00
I fixed it. I desoldered all the diodes to the knobs and added them back one by one. It was a faulty ...

Thanks for your share.

Author: user567121    Time: 2020-10-19 00:23
Edited by user567121 at 2020-10-20 04:25
Znida replied at 2020-10-10 17:00
I fixed it. I desoldered all the diodes to the knobs and added them back one by one. It was a faulty ...

good to hear that you solved it    

Is it 100% fixed for you now?

I will resolder and investigate mine too. Was it perfectly working after you made one knob (the faulty one) inactive by desoldering its diode and this defective knob was suppressing all the other knobs? You say you did it other way round, you desoldered all diodes and put them back one by one and suddenly all began to fail. right?

And the source of evil was the knob itself you say..? but there was nothing strange with it..

Hope i can trace my error the same way down to a rotary knob. If you had the same faulty behavour  like mine before then i think chances are good. (mine fails most of the time complete on all knobs, buttons also don't work, sometimes out of nothing they work perfect for a couple of seconds or minutes just to fail completely and won't get back to good, or only for a short time - i did a resolder on almost every part and connector and tried to check the keyboard cable etc..no changings, haven't try to investigate signals of the knobs itsef which would be interesting i think (i'm no expert in this, more general electronics) but because measuring the board without another oscilloscope on an open case and a mirror makes you crazy in no time)


hope the best, regards


Author: amy    Time: 2020-11-30 13:52
Edited by amy at 2020-12-5 10:52

It may also be that one knob is faulty, causing other knobs to fail to work.Please remove the cap of the knob to check.
If no problem is found, please disassemble the machine for inspection.
Please cut off the power before disassembling the machine. Take care to avoid touching the power board during the test.

Test whether some of the pins of all knobs are shorted to ground.
If there is a short-circuited pin, it may be that a certain knob is broken.



Author: user567121    Time: 2020-12-9 00:10
Edited by user567121 at 2020-12-9 01:45

i removed the tiny diodes from the knobs, after the second knob, the V/DivCh.A-Knob in my case it worked for longer time without errors, so i soldered back all diodes except for the faulty V/Diff(ChA) Knob and it is working good. Now i will dissable the knob and look inside and maybe i will look for a replacement. My rotary encoder is shortend to gnd at one of its three pins (unlike all other encoders on the board)

thanks for your all the help, i will tell if it is fixed complete


Update: fixed - it was the knob (rotary encoder) !
It had a shortcut from its metal body case to one of the three contacts. (THANKS for the info @Amy !)  It was kind of cheap factory production i guess because it is a bit misterious. Inside the knob was everything okay and you can barely see it, but if you open the 4 metal clamps which holds the knob together you maybe see the problem. The main plastic body part has these integrated contacs, they are in risk that the edges of this part with contacs will touch the metal clamps if the housing is closed by bending them over.

So after i have opened the knob i closed it not so tight it was working again.

regards






Author: morgan_flint    Time: 2023-9-19 17:07
I see the thread is old, but in case somebody lands here after a search, a similar problem's solution here




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