naujoks

As mentioned, I tested the mechanical part of the drive on a different motherboard, and it's working.

I have an Atari 1050 with a non functioning spindle motor. The mechanical drive section actually works fine, as confirmed when installing it on a working mobo. The faulty mobo shows signs of a previously botched job, a ripped up trace here, a cap with inverted polarity put in there (why it hasn't blown up I don't) know, a broken (and unfixed) tantalum cap, the voltage regulators have been replaced, as well as Q6 TIP 110. I've cleaned up the mess as far I could see it and I am getting 5V and 12V on the board (5V perhaps somewhat low, at 4.86V?). I've replaced the socketed ICs with known working ones. On switching it on, the self test performs and the stepper motor moves back and forth, the LED lights up for a second, but there is no disk rotation. As per the field manual, I checked Q4, which tested fine. It also says to check the LM2917 at U5. Is there any way to find out, if that part might be faulty, without desoldering it? Any other things I could check at this stage?

Good to know you're still alive though!

Necro thread revival: This just gave me colour back on my 800XLF! Just how did you find out that it was that cap? If you can remember anything about it, that is!

So it turned out to be a bad capacitor at C304 (incidentally, the markings on my PCB don't correspond at all with the provided schematics), which sits right under der FREDDIE, to the right of the 14.xxx MHz crystal - surprising that it should be within that area. I discovered it following this thread: I would have had a hard time finding this myself, since my crappy component tester doesn't even read small pF values. I used 22pF, didn't have 18pF at hand. I needed to set the colour pot almost all the way clockwise, but regardless, I have colour, and it's such a glorious picture on those Sony PVMs!

Yes, I tested it with my other 800XL. Svideo only has 4 pins, so it's not difficult to get it right. I will check the components around the crystal since I'm not getting the right measurements there.

I'm using a cable which I put together myself, 5 pin on the Atari side, SVIDEO plug on the monitor's side. It's worked well with all 800XLs and 800s I've had.

I don't have crystals of the precise value at hand, but just for giggles I took the crystal of an Atari Portfolio, which is 4MHz sometihng. The picture doesn't change at all, but when I measure this crystal with the scope, it showed the same erratic reading as the original crystal (incidentally I only get a reading at one of the contacts). I don't know much about crystals, but even if this crystal isn't the exact same one as the original one, shouldn't I get the MHz shown that this crystal has?

Yes, I don't have a TV, it's a PVM monitor. I just checked the Y2 crystal with the scope and couldn't get a clean reading at all, so maybe that's the fault. If I were to take out the crystal altogether, should the picture remain the same as it is?

I just connected my other 800XL via cinch (called TV on the computer) and the monitor, and that gives me a black screen as well.

Playing with the pot on the board gives me a bit of a blue picture at one setting, but that colour doesn't have anything to do with the real colour, so just some weird artefact, I think. I have no experience with composite video. Should I be getting a picture by hooking up a cinch cable from the connector on the board to the monitor? If so, there's something wrong with that as well, as I'm only getting a black screen.

I can confirm that pin 5 of the video out is indeed connected to something. Does the cable that I use on my other 800XLs need to be wired up differently, maybe?

On my monitor I'm only getting a b/w picture though (svideo input).

Yes, it's PAL (nice deduction!).

I'm trying to do an svideo mod on my 800XL, but my board revision (rev. 3, 9/84) has a very different video out section (see pic). Does anyone know how to do the svid mod on this revision? I'd just want to do the "quick and dirty" mod that runs one wire to pin 5 of the socket, which gives me a great picture on my Sony PVM with my other Ataris. To matters worse, most part names are printed UNDER the respective parts, so even if the components have the same name, it would still be difficult to locate them.

I haven't removed any caps. Which ones are the ones to be removed?

I just installed an Ultimate 1MB in my 800XL. I wanted to use it with my Fujinet, but it's not working. It's trying to boot sometimes but then halts, sometimes it boots successfully but then freezes during operation. I tried what's been suggested elswhere, booting into SpartaDOS, then resetting Fujinet and typing COLD /N, but that doesn't work either. I connected the Fujinet to USB power, that seemed to make things a bit more stable than without, but not much. Anything else I could try? Is Fujinet and U1MB not the best combination? What's better?

I put together a Rocks 'N' Saucers on one of these PCBs: https://github.com/technobly/vectrex-cartridge All working fine, now I wanted to add the LED, which I did alongside the other components, but the LED doesn't light up. My double checked my soldering work, and that seems to be fine. The little mini LED I installed with the triangle symbol pointing to top left (when looking at the PCB with the fingerboard pointing down). When is the LED actually supposed to light up? Not sure what the problem could be, there isn't much to get wrong. The LED I got is of this kind: https://www.ebay.de/itm/383258885066?var=651768669796 I bridged the RGB connections while I'm waiting for the dip switches to arrive from China. Very grateful if one of you could confirm that I ineed have i the right way round.

I now bought HDDRIVER, and everything is working fine with it.

I've just tried a different adapter, this time a CF- IDE adapter. The result is the same. I can boot from floppy disk without problems, install the HD, arrange booting from HD, and on restart, when I try to install MultiTOS, I get a read error immediately or after 2 or 3 copied files. The floppy/Gotek is unsuable after that, I can't open or copy anything until another restart. The HD seems to work just fine, at least the directory doesn't get scrambled. I just haven't been able to put any data on to it. When I boot from floppy but without a SD/CF card inserted in the adapter, it boots just fine and I can do everything. The problems start as soon as there is a card in the adapter. Any further ideas what could be wrong?

I checked the voltage, it's bang on 5V. I can't say anything about stability though. This is the adpater I'm using: https://www.amazon.de/gp/product/B07B66QJHK/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

YAART reports no errors. I have now an indication that problem lies elsewhere. I removed the SD card from the SD-IDE adapter, so that the computer boots from floppy/Gotek. This makes it work without problems. Once I boot from SD card, the old problems are back. Could it be that my SD-IDE adapter messes with the Falcon? Any recommendations for SD-IDE adapters that are known to work well?

Is the power on RAM test not sufficient? Is there another app to test it?

I have a weird problem with the floppy in my Falcon: Sometimes it reads directories and files fine, but when I install something and it needs to load multiple files, it breaks off with an error. I can reproduce the error by double clicking on the drive icon. If the diretory shows fine then and I press the ESC key, it shows only garbage. If I press it again, it shows the directory again just fine, but I can't load any files (TOS error #35). if I press the ESC again, garbage etc. This happens with the original floppy drive as well as a Gotek. Any idea what could be wrong?

Well I'll be... It WAS the Delay Line IC! All up and running now. Thanks for the help!