From: Gabriele Bozzi (mabuse68_at_gmail.com)
Date: 2006-06-10 13:51:23
Hi, Before going deep into "digital" or signal generation my humble advice is to check the high voltage section for cold soldering or broken contacts. As I mentioned before: check for good contact on each of the high voltages coils on the video ramp signal as well as eventual exploded capacitors. Eventually checkong for signals: do not try to use an oscilloscope there since the impedance of the probes gather signals already from 20cm away :) You need usually to trigger to vertical signal.. (am I right? vertical? It's a hell of a time thet I do not repair a video ...). Have a nice weekend. Gabriele On 6/10/06, firstname.lastname@example.org <email@example.com> wrote: > Hello, > > I put a 4032-32N next to my 2001, connected the 2001 monitor to the 4032 > motherboard and I got a normal screen display (4302). It's a bit bright > but it's the display is full screen. > > I think that the video circuit of the 2001 is not working correctly. > I presume it starts at the upper left corner. Gets a bit from the shift > register B2, the beam moves a bit to the right another bit is fetched and > so on.The beam moves a line down and starts again. Eventually it goes to > the bottom right corner. > > I'm thinking that the "counting or setting" of the lines does not work > anymore except for the 3rd quarter of the screen. It could be that the > charROM is not perfect but I don't have a 6540 that I know it's perfect to > swap. > > I'm trying to understand the "counting or setting" of the lines but the > schematics are to complex for me. > > Also there is a BLANK signal at E9 (Last NAND before the monitor > connection) is this to shutdown the beam to prevent flyback to be visual > on the screen? Could it be that somehowe the BLANK signal stays on too > long (first and last part of screen?) BLANK comes from G8 (CA2 / PIA#1) > Or is it used as in a C64 to just blank the whole screen. > > I noticed ther are a lot ot testpoints on the schematics. (TP5-1, TP2-1 > and so one) Is there a manual how these work, I think that they are point > you can ground and a certain effect can be seen. Most of the testpoints > are pulled up to the 5VDC with a resitor. > > greetings Richard > > > Op Vr, 9 juni, 2006 7:34 am schreef firstname.lastname@example.org: > > Hallo Richard, > > > > > > > >> I would say that, first of all, some issues with vertical > >> deflection are there. > > > > I second that. > > > > > > > >> Furthermore: on the user port of the PET you can extract a composite > >> video signal. > > > > That is a good option, but may be a better one: what about connecting > > anpther CBM monitor? IIRC the 2001 has the same pinouts as all newer CBM > > series so you should be able to connect thew monitor of a CBM 8032 for > > example. > > > > > > -- > > ___ > > / __|__ > > / / |_/ Groetjes, Ruud > > \ \__|_\ > > \___| URL: Ruud.C64.org > > > > > > > > > > > > > > > > > > > > > > > > > > > > =====DISCLAIMER========================================================== > > ======= > > > > > > De informatie in dit e-mailbericht is vertrouwelijk en uitsluitend > > bestemd voor de geadresseerde. Wanneer u dit bericht per abuis ontvangt, > > verzoeken wij u contact op te nemen met de afzender per kerende e-mail. > > Verder verzoeken wij u in dat geval dit e-mailbericht te vernietigen en > > de inhoud ervan aan niemand openbaar te maken. Wij aanvaarden geen > > aansprakelijkheid voor onjuiste, onvolledige dan wel ontijdige > > overbrenging van de inhoud van een verzonden e-mailbericht, noch voor > > daarbij overgebrachte virussen. > > > > The information contained in this e-mail is confidential and may be > > privileged. It may be read, copied and used only by the intended > > recipient. If you have received it in error, please contact the sender > > immediately by return e-mail; please delete in this case the e-mail and > > do not disclose its contents to any person. We don't accept liability for > > any errors, omissions, delays of receipt or viruses in the contents of > > this message which arise as a result of e-mail transmission. > > > > > > > > Message was sent through the cbm-hackers mailing list > > > > > > > > Message was sent through the cbm-hackers mailing list > -- *********************************************** Gabriele Nicola Bozzi SANAE VoF Beveren - Belgie A: Maybe because some people are too annoyed by top-posting. Q: Why do I not get an answer to my question(s)? A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? *********************************************** Message was sent through the cbm-hackers mailing list
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