diyAudio (
-   Parts (
-   -   Oscilloscope Channel 1 problem on BK Precision model 2120 (

albertho 16th October 2007 06:44 PM

Oscilloscope Channel 1 problem on BK Precision model 2120
This 2nd handed oscilloscope's channel 2 is in function but the channel 1 found no reaction to signal input.
The channel 1 can shows the beam line and can be positioned up and down.
Is there any link I can download the services manual or schematic?
Or could anyone give me some guidance to repair the fault channel.
Thanks very much in advance.

unclejed613 20th October 2007 10:21 PM

most common problem with scope inputs is either an open resistor in the attenuator switch, or a blown diffamp transistor. the input amp of an o-scope is very much like in an audio amp, a diff pair with a current source. the diff amp feeds symmetrical VAS stages all the way to the deflection plates. between the input and diff amp, you have a stepped attenuator. if your trace can't be centered on the screen, suspect the amp section. if you can center the trace, suspect the attenuator.

JMscope 24th January 2017 04:33 PM

BK precision 1477 auto sweep
I have an old BK 1477 scope. Most functions seem to work okay, but the auto-sweep does not trigger any horizontal trace. If I connect a signal, I can trigger on it but the "auto" trigger does not function. Can anyone give me a hint on repair of this issue? Thanks.

All times are GMT. The time now is 07:05 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2