Hitachi V202 oscilloscope issues - diyAudio
Go Back   Home > Forums > Design & Build > Equipment & Tools
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Equipment & Tools From test equipment to hand tools

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 3rd September 2003, 05:35 AM   #1
diyAudio Member
ashok's Avatar
Join Date: Jun 2002
Location: 3RS
Default Hitachi V202 oscilloscope issues

I have an old Hitachi V-202 20 Mhz oscilloscope.
During the rainy season we had a really bad day and some moisture condensed on the components. When I turned it on it blew some TO220 type power transistors on the main board. I replaced these. The display however seemed to loose intensity control . So I had to solder a 3.3M resistor in series with the control grid ( I think) and it now has a fixed acceptable brightness.

All other parts 'seem' to be OK. Does anyone have any idea what is happening ? I have a circuit diagram of the intensity control circuit which I will scan and post later. I did see a flash around the connector of the CRT when I opened it and turned it on ( at the time it failed). That must be responsible for the blown power transistors.
I am able to use the unit now though the intensity is fixed. It also lost its ability to have an external (Z) intensity control.
It used to be a good scope - still is ! I wish I could fix it again.
The slide switches for the ac/gnd/dc are very hard to operate and have poor contacts. Can I use any switch or should I get them as spares from Hitachi ?
What is the best contact cleaner that I can use ?
  Reply With Quote


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
hitachi ha-330 modification adason Solid State 45 15th January 2017 09:49 AM
Hitachi HA5300 ? Zen Mod Solid State 44 10th January 2016 03:28 PM
Hitachi Cap?? peter7 Pass Labs 4 20th April 2011 10:37 PM
Crazy issues with an Heathkit oscilloscope 00940 Equipment & Tools 2 5th May 2009 11:47 PM
Hitachi D-E66 GW4JUW Analogue Source 1 4th September 2005 07:44 AM

New To Site? Need Help?

All times are GMT. The time now is 04:50 PM.

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