Aron BS-601 Oscillosope (Hung Chang OS-602 rebrand) Horizontal Issue

[obrim]

Hi Guys,

My first post here, been a long time lurker but really need help with this issue I'm having with my CRO.

Its an Aron BS-601 which I got for $40 and works great except that when I set the TIME/DIV knob anywhere between 5ms-.1ms (6 clicks) the trace wont go across the screen it just get stuck at the very LH side. I am getting vertical just no horizontal.

I have already replaced a couple of capacitors on the horizontal board which were leaking but didn't fix the issue.

I have uploaded a video to youtube so you can see what is happening and also linked to the schematic that I am using.

Any help would be appreciated or even just a nudge in the right direction . I am determined to get this working properly!

Schematic: https://elektrotanya.com/hung-chang_os-620_sch.pdf/download.html

YouTube link: https://www.youtube.com/watch?v=9ngK6DQTbM8

Thanks,

Mick

 

[E-design]

It appears that one sweep range is faulty. You may also want to look for a broken wire or track to the pins on the sweep selector switch around C20.

 

[obrim]

Thanks mate I've checked the tracks leading to the switch and all seems ok, I'm going to change c20 though and see if that fixes it. Will update if anything changes.

 

[obrim]

So replaced c20, all good. Now have full sweep range!

Thanks for your help!!

 

[E-design]

Was it open or short circuited?