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DistantStar001

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About DistantStar001

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  1. Thanks for this, I did manage to narrow it down to U2. Just replaced it today and now my C64 and 1541 are back on speaking terms! I had no idea no idea old computers had such complicated love lives! Although in my case there's a happy ending!
  2. If it's an American version, then the prongs are the same as a power cord for most electric razors. You could do what I did, cut off useful end and solder on a barrel jack to the other. After that, any 10-15 volt supply at 2.5 amps will work (even if it's DC).
  3. One of my c64's just stopped communicating with its serial port. One moment it was fine, as I was just trying to get it to change the drive number on a 1541, and the next, I tried retrieving a directory, and then nothing. It just sits there "searching for $". No curser. Just searching. As for the drive. There is no response. The red LED won't even light up. However, the drive does reset when I power-cycle the computer. I've tried two drives and a Pi1541 with much the same result. I tried three different serial cables as well (two I had made myself, but the third was original to one of the drives). I then tried both drives on two separate c64's. Admittedly, the first gave me a "Device not present error", but I reflowed the solder on the serial port and now both drives respond as expected. The second had no problems with either drive. The drives also responded as expected to a VIC-20 as well. So I'm reasonably sure the issue is the computer. I did open it up. Didn't want to, since it was sealed over the center screw with a warranty sticker and I wanted to keep it pristine. But as it turned out, there was no point as it was from a repair shop and whoever was in there had replaced the PLA and SID as at some point and failed to clean up their flux. I cleaned that and reflowed the solder on the serial port (didn't think that would help, but worth a try). Sadly no luck. At least I got rid of that stupid cardboard RF shield. The computer seems to boot normally. There is a curser on the screen. No graphical corruptions and the keyboard is fully functional. As far as I can tell, the joystick ports work. (hard to test fully as I don't have a harness for diagnostics, and I can't load any software that would make use of a paddle or mouse). I think it might be one of the CIA's, but want to explore all possibilities before I I take a soldering iron to it. Also, if someone could tell me which CIA I should focus on, that would be appreciated. Very Happy Side Question: I've tried changing the Drive number a number of times with no luck. I'm typing the command directly from the original VIC-1541 Single Floppy Drive User Manual with no luck. Every time the drive still thinks it's device 8. The commands I've been using are: OPEN 15,8,15 PRINT# 15, "M-W:" CHR$(119)CHR$(0)CHR$(2)CHR$(10+32)CHR(10+64) Tried this with and without spaces CLOSE 15 I don't always do this line I'm trying for device 10, since my Pi1541 is set to 9, and I want to see if I can get all three to work together. Also, I don't want to permanently alter my drives as I have several c64's and VIC-20's so the drives do get swapped between them. In any case, What am I doing wrong?
  4. Thanks!!! Looks like a noisy PSU. Kind of a shame, though. It's the original. Maybe replacing the filter cap will help matters. In the interim, I spliced a din connector onto an old laptop charger. It seems to have cleaned the image up considerably. Although I will probably want to recap the internal regulator when I get a chance.
  5. I replaced the regulator! So now my //c is back and running!!! For those who might be curious, the short between pins 11 and 12 is normal as it is present on the working regulator as well. I still haven't given up on the original. But now I have a working example as a guide to diagnose whatever the defective component is. So far, I've replaced the DUV26 Transistor at Q2, the HA17339 IC, all of the electrolytic compactors, and the regulator abled IC2 (not sure why it was abled that way). I've also checked all of the diodes in and out of circuit. Basically, I've been poking blind. Hopefully the working one will point me in the right direction. I'll post again if I figure it out. An additional question: I noticed that the text has a noticeable rainbow-bleed on the screen. Admittedly I'm using an old SAHRP CRT TV from the 90's, but its a bit more severe than it should be. I remember a similar issue just before the old regulator died. It took several years. And at first, I thought it was just the natural result of having been in storage for more than a decade. But it got really bad the day it died. Then the video started to cut out, and it just shut off and wouldn't power on again. So I'm a little concerned about this. Any suggestions on how to keep my beloved //c healthy would be appreciated.
  6. Just out of curiosity, Does anyone know a US seller who carries a ready-made Amiga 500 compatible Gotek? I've been looking into it, and near as I can tell, it's actually more expensive to piece these together (Gotek, OLED, and mounting bracket) than it is to simply get the ready made one. Or at least it would if I were in Germany. In the US, shipping makes it a bit of a wash. But before I go about importing one from the other side of the world, maybe someone could point me to a more local source? Or atleast on the same continent? Also, just to reiterate, as I am really new to the Amiga, and I don't think I say this often enough... Thank you all so much for all the help and suggestions given to me so far. You've all been very helpful and supportive!!! 🙂
  7. So the good news is that I was able to determine that the HA17339 has failed and I was able to install a replacement. However, it didn't solved anything. The lines that connect pins 11 and 12 are still shorted elsewhere on the board as well, and I still don't know if this is normal. All I do know is that they're not supposed to be on the chip. It also occurred to me that I forgot to mention which regulator I'm working on. It's an Astec AA 7343A. Hopefully that will help. I've been looking everywhere for a schematic for this. But so far, I haven't had any luck. If anyone has this (or even just a layout of the traces on the PCB) it would be extremely helpful.
  8. Unfortunately, I already have this. While, it was very helpful in identifying some components, my //c is a little newer. So the schematics don't exactly match. From what I can tell, the IC in question isn't even present in the regulator documented. Thanks though. Even if it didn't help with the problem at hand, this is a terrific manual and very informative! Honestly, every //c owner should give it a look over. 🙂
  9. A while ago, my trusty //c decided to be a little less than trusty when it burned out both the fuses on the motherboard and in the power supply. I've since replaced the fuses and managed to trace part of the fault to the DUV26 Transistor at Q2 on the voltage regulator board, so I replaced that too. Now it no longer burns its fuses (good news!) Unfortunately, I'm still not getting a 5v output from the regulator. I've removed and tested all of the capacitors. The all tested good and showed no signs of bulging or leaking, so I put them back and continued probing. That's when I came across something odd. The HA17339 IC is grounded on pin 11. I looked up the data-sheet and pinout, and from what I can see pin 12 should be the only ground. 11 does have the expected continuity (with resistance) with + on 11 to - on 13 (but not the reverse), as well as from pin 10, with + on 11 and - on 10 (again not in reverse), which seems to correspond to the data-sheet. However, the sheet makes no mention of 11 to ground. Is this normal? Or should I be replacing this IC? Also are there any other points of failure that I should be looking for? As always any assistance is appreciated. 🙂
  10. Good Point! So I looked elsewhere. Disassembled the whole thing, and tested the board, and it came back to life! So I reassembled it, testing power as I added back components. Long story short, I discovered that the issue is in the floppy drive. The TA774P is blown. Must have been that popping sound I heard. Not sure why it went though. I figure it shouldn't be too hard to replace, provided they're still in production. In the interim, that Gotek is looking better and better! Thanks for this! I didn't manage to get it out (probably being overly cautious with it), but I did manage to rock it a bit in the socket. Now the glitching is gone!
  11. You're right. The +12 and -12 volt lines are shorted to ground on the board. Removing the keyboard (and shield) didn't help, but the connector looked to be offset by one pin. I didn't mess with the Floppy connector so that should still be fine. I started testing any component that looked to connect power to ground and found that the component circled in the image (at LF1) is shorted, but not the component below it. I'm still probing the board, but this has me wondering if this might be my issue? Forgot to mention that this is an issue 5 board.
  12. Thank you!!!! CAS2Audio made all the difference! I've managed to load several cas files through it and even record to real tapes with my TI Recorder!!! Off topic, but do you think it would work for a TRS-80 Model III?
  13. Thank You! Spy vs Spy loaded perfectly (on its second try). So at least I know this thing is working! I would still like to be able to convert .cas files, but this is a very promising start!
  14. Any recommended software for this? Or an alternative to TapDance? I tried both cas2wav and a8cas, but Windows 10 won't let me use the first, and the second just crashes. I haven't been able to get them to work through Wine either.
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