Humm...just looking at the schematic again, maybe I made a mistake in my selection of Tant capacitors. The schematic says 1.0 25v so I purchases a 25v 1.0uf capacitor, but looking at the part I removed through a magnifying glass, it says 1k 35v. I'm guessing that 1k=10uf. If so, in that case I bought and installed the wrong parts. On Aug 17, 2009, at 11:05 PM, Philip Lord wrote: > Update: > I have replaced nearly all the power circuit components: > > 4 x 7805 voltage regulators > 3 x 1.0uf tant Caps (C11 thu C13) > 4x 16v 47uf Caps (Actually replaced with 25v 47uf) > 1 x CR3 Diode (replaced with 3004) > > ...and nothing has changed. I still reading about .31 MVAC on the > cathode of CR3, and the machine is still dead as a dead thing!!! > > The only things i didn't replace was CR1 and CR2 and C51 and C50 > > So frustrating! Not sure what to do now :-( > > Phil > > On Aug 17, 2009, at 1:12 AM, Nate Lawson wrote: > >> I agree. I went there a few times in 2005-2006 and it wasn't the >> same. >> Raw components were hard to find, and the sleek consumer electronics >> stuff had moved to mega stores like Bic Camera in other areas of >> Tokyo. Sad. >> >> -Nate >> >> Philip Lord wrote: >>> Yes..I'm quite privileged to have such an electronic mecca just >>> 30mins >>> away. >>> Unfortunately Akihabara as I once knew it is dead (or at least >>> it's in >>> it's death throws). Gone are most of the small 'nook and cranny' >>> stores >>> where you could rummage for hours and find all sorts of interesting >>> junk. It's now populated by Otaku anime and Cos-play shops and multi >>> floor mega stores. >>> >>> :-( >>> >>> >>> On Aug 13, 2009, at 10:54 AM, Bil Herd wrote: >>> >>>> All us old Commodore types used to hit Akihabara whenever we were >>>> in >>>> Tokyo. Rumor has it that CBM-J would occasionally run down there >>>> to >>>> buy a few scoops of 7407's to keep production flowin. >>>> >>>> Bil >>>> >>>> -----Original Message----- >>>> From: owner-cbm-hackers@ling.gu.se >>>> [mailto:owner-cbm-hackers@ling.gu.se] On Behalf Of Philip Lord >>>> Sent: Wednesday, August 12, 2009 9:37 PM >>>> To: cbm-hackers@ling.gu.se >>>> Subject: Re: Dead PET 2001 >>>> >>>> Great! >>>> I'm going to race into Akihabara this lunch time and get all the >>>> CR3, >>>> C11, C12, C13, VR3, VR4, VR5, and VR6 parts. >>>> Hopefully I'll have time this weekend to attack the board starting >>>> with the CR3 diode. >>>> >>>> Thanks again for your help, and I'll let you know how I go. >>>> >>>> Cheers >>>> Phil >>>> >>>> >>>> >>>> On Aug 12, 2009, at 2:40 PM, William Levak wrote: >>>> >>>>> On Wed, 12 Aug 2009, Philip Lord wrote: >>>>> >>>>>> I was just about to say that Pin2 is connected to one of the red >>>>>> leads that goes to the capacitor, therefore with the red leads >>>>>> disconnected there would be 0V at pin2, but instead I decided to >>>>>> test it anyway...I got 0.5VDC!!!! Then I realized what is >>>>>> happening: >>>>>> >>>>>> When I disconnect the two red leads from the capacitor, but still >>>>>> have the two leads connected together the voltage reads 0.5VDC at >>>>>> pin4 and pin2. When the red leads are disconnected from the >>>>>> capacitor, and also disconnected from each other I get just over >>>>>> 8VDC at pin4, and 0VDC at pin2 (as expected). >>>>>> >>>>>> ...as for a glow from the monitor filliment, I had to turn off >>>>>> all >>>>>> the lights to see it, but yes indeed, there is a glow. >>>>> >>>>> This is good! This means that the transformer, the big filter >>>>> capacitor, and CR1 and CR2 are all good. >>>>> >>>>> The problem is localized to CR3, C11, C12, C13, VR3, VR4, VR5, or >>>>> VR6. One or more of those is bad. The prime suspect is CR3. If >>>>> it >>>>> was working, you should see 8V on pin 2. These diodes get hot >>>>> when >>>>> operating. If it is cold, it is probably open. >>>>> >>>>> Now would be a good time to remove the circuit board. Small >>>>> things, >>>>> like paper clips, sometimes get trapped under there, and short >>>>> things out. >>>>> The screw on the left rear of the board is a ground to the chasis. >>>>> The others should not contact any circuits. >>>>> >>>>> wlevak@sdf.lonestar.org >>>>> SDF Public Access UNIX System - http://sdf.lonestar.org >>>>> >>>>> Message was sent through the cbm-hackers mailing list >>>> >>>> >>>> Message was sent through the cbm-hackers mailing list >>>> >>>> -- >>>> This message has been scanned for viruses and dangerous content by >>>> IDSi's MailScanner. >>>> >>>> >>>> >>>> Message was sent through the cbm-hackers mailing list >>> >>> >>> Message was sent through the cbm-hackers mailing list >> >> -- >> Nate >> >> >> Message was sent through the cbm-hackers mailing list > > > Message was sent through the cbm-hackers mailing list Message was sent through the cbm-hackers mailing listReceived on 2009-08-17 08:00:57
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