Dies ist eine mehrteilige Nachricht im MIME-Format. --------------997AE90775CFA195642A509D Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Er, maybe the list is interested in this, too Greets Jochen Feldhaar --------------997AE90775CFA195642A509D Content-Type: message/rfc822 Content-Transfer-Encoding: 7bit Content-Disposition: inline X-Mozilla-Status2: 00000000 Message-ID: <3C67BE91.26A06B21@telejet.de> Date: Mon, 11 Feb 2002 12:52:33 +0000 From: "J.Feldhaar" Organization: Telejet GmbH X-Mailer: Mozilla 4.73 [de]C-CCK-MCD DT (WinNT; U) X-Accept-Language: de MIME-Version: 1.0 To: Vit Subject: Re: [OT]: Tektronics 475A Repair Manual/Tips (no horizontaldeflection) References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hi Vitaliy, for the horizontal deflection plates there is a separate supply voltage that is used almost exclusively for the X final amp. Open the set, there should be abt 50 Volts (vertical) and 100-120 Volts (horizontal). TEK has test points inside for these voltages, they are labelled. Maybe it was just a transistor in the power supply that blew... Greets Jochen Feldhaar DH6FAZ Vit schrieb: > > Hello everyone, > > Until last night, my experience with the used Tektronics 475A oscilloscope I recently bought on eBay had been only positive. But yesterday, when I powered it on, the whole screen lighted up, then started blinking at a rate of about 1Hz. I've never seen it do anything like that before, so I tried adjusting the knobs. For about five seconds, there was a diagonal line going across the screen, then it went blank. > > I turned off the instrument, let it sit for a few minutes, then powered it back on. A dot appeared in the center of the screen, and it stayed that way since. When a signal is applied, you can see a vertical line whose lenghth is proportional to the amplitude of the signal. > > Tektronics discontinued this model in 1985, and I couldn't find any information about the scope on their website, except that it had now been replaced by the TDS380. Searching the web produced no results either. > > I know that Dale and a few other people owned (or still own) the 475A model. Can you guys give me some pointers on where to start? I don't feel comfortable getting inside the scope without some kind of plan.. > > Sincerely, > > Vitaliy > > P.S. There is a *possibility* that the scope suffered some thermal damage, because I accidentally covered up the ventilator hole in the back of the oscilloscope.. > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu --------------997AE90775CFA195642A509D-- -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads