power suply bob4

Anything about this unique oscilloscope DIY kit
stromar
Posts: 15
Joined: Tue Aug 29, 2017 5:26 pm

power suply bob4

Post by stromar »

Hy

I have resolder new c5 variable condenser. When i try to power it up nothing hepend. Then i check powre suply points v+ and vs+ are ok around 5 volts but +5v is only 0.5 volts. So in the asembely guide it is writen that there must be problem with bob4. I have chek it and resolder capacitor, and stil no working osciloscope.

Now i went to store and i have buyed new 100microfarad 20 v capacitor.

Cam enyone help with this problem.

Everthingworked until i hit the wawe form check. Part where you conect frequency generator and you adujsted lcd wawe forms.

Help woud be apricieted.

thanks.
stromar
Posts: 15
Joined: Tue Aug 29, 2017 5:26 pm

Re: power suply bob4

Post by stromar »

Hy

I woud realy love to finisch my osciloscope.

can sombody help me on thise.

Is eny posibility that i can yend osciloscope to you and you reper it and send it back.

Thanks.
stromar
Posts: 15
Joined: Tue Aug 29, 2017 5:26 pm

Re: power suply bob4

Post by stromar »

I finisched power step 2 and went to power step 3, then i cnaged capacitors c5 and c8.

Now i went to check NO POWER

usb powered ok 5.08
VBUS ok? ok 4.9
V+ ok? ok
VS+ok? nok 0.22
+5V ok nok 0.58

BOB 3 and bob 4 is instaled
jp1 is closed jp2 is open
jp3 open
jo7 closed
jp9 closed
sw12 dont blink
lcd dont power up

eny sugestions

i yust put a new capacitor c5 and c8 on the bord,....
stromar
Posts: 15
Joined: Tue Aug 29, 2017 5:26 pm

Re: power suply bob4

Post by stromar »

BOB3
in 4.91
out 0.22

BOB4
in 0.22
out 0.55

This is voltagemesured from bobo 3 and bob 4 to reference point

So eny sugestions,...
stromar
Posts: 15
Joined: Tue Aug 29, 2017 5:26 pm

Re: power suply bob4

Post by stromar »

jp1 4,91
jp2 one side 4.81
other side 0.22

jp4 0.55
jp 7 0.55


ok this are voltages at teh junktion,..

Can sombody tell me what is wrong,.. becose inthe manual writes taht is somthing wrong with bobo 3 and bobo 4 i didnt tuch them ,..


Thank you.
jye1
Posts: 1221
Joined: Wed Feb 20, 2013 4:58 pm

Re: power suply bob4

Post by jye1 »

Please close JP2 and see. It looks BOB3 was not turned on. Closing JP2 bypasses BOB3 so you can test the rest circuits first.
stromar
Posts: 15
Joined: Tue Aug 29, 2017 5:26 pm

Re: power suply bob4

Post by stromar »

Hy

i closed jp2

lcd is working
presing buton saunds the beep

Vbus 4.55
JP1 4.20
JP2 4.2
VS+ 4.20
+5V 5.02
JP4 5.02
JP7 5.00
JP9 0
BOB3 in 4.20
BOB3 out 4.20
BOB4 in 4.20
BOB4 out 5.0

So then is problem in BOB3, shoud i resolder it and solder it back again. Or i order spere part from your companywait for it and solder new one one the circuit.

Thank you wery mutch for your reply and help.

I will proced with adjusment of c5 capacitor while i am waiting foryour reply.
jye1
Posts: 1221
Joined: Wed Feb 20, 2013 4:58 pm

Re: power suply bob4

Post by jye1 »

It is suggested to check all related connections including parts on the small board. Replacement is free if the problem is caused by issue of the 117 board.
stromar
Posts: 15
Joined: Tue Aug 29, 2017 5:26 pm

Re: power suply bob4

Post by stromar »

Hy

I desoldered, cleaned, and looket at conections terminals and parts via magnifeing glass. I didnt fount nothing strange i dont now. I solder it again and the same thing. Board is dead.

I mesured voltage on bob4 junktion (in) is 4.90 but on bob 4 junktion (out) is only 0.30 v.

so somthing isnt ok with this board.

Where can i get the replacment or who i can contact, can you give me a contact.

I have completet calibratin of wawe form form with c5 and c8 condenser with on bord signal generator 10.000 hz.

But i cant get sharp edge on one of the part of wawe form.

Here are 2 pictures. One wewe form is distortet c8 second wawe form is ok c5.

Is this ok or shoud wewe form with c8 have sharp edges too.

Thanks for answers.
Attachments
c8
c8
c5
c5
jye1
Posts: 1221
Joined: Wed Feb 20, 2013 4:58 pm

Re: power suply bob4

Post by jye1 »

Please contact us at jyetech@163.com for BOB4 issue.

C5 is good. For the C8 calibration please see the section "Calibrating C5 and C3" under Assembly Tips. This post was for DSO Shell but the same method can be used for DSO 068.
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