dukes909

I think what I have is correct?!

I have a scope that I am still learning to use!😛 But not sure what I am looking for.

Unfortunately the 2nd drive has the exact same symptoms 😑 I've swapped all the boards with no progress.

Nope

By the way, should there be a resistance reading between 3 & 4, 4 & 5, and 3 & 5 on the drive head connections at J209? For one drive mechanism (I have 2 non-working 810's) I show all 3 of those as being open, no resistance/impedance. For the other drive mechanism I show 8ohms for 2 of them and 14ohms for the 3rd. It seems like the first drive mech is shot?...

J209 is solid and I have continuity across each wire from the connector to the associated points in the head. I need a little help there; am I looking for voltages there, or activity using a logic probe or something else?

Great find - thanks

While we're at it, does anyone have a good schematic of the analog board?

Good question, I'd like to know as well. I wonder what is in the revision 3 version of the FSM or if it is available anywhere for download like R2.

Wow, did not know about this, thanks. For what it's worth I downloaded a timing light app for my phone and used the pattern on the flyweel to set the speed to 300rpm and then 288rpm. No difference reading disks or booting from them. 🙄

That's the one I've been using. Only thing I see is swapping data separator board with a known good one, which I don't have.. 🤨 Interesting, I may have to call and order that!

I think mine is a newer power supply board; it does not have A110. The waveforms on the other chips check out...now what!?

Well, mine doesn't have an A110 anywhere so that's a no-go..I'm thinking the field service manual is not the correct one for my model? I have a Revision C analog board.

So if I'm looking at correct manual that would be: Check A109, pins 7,3,2 for correct waveforms Check / replace A110 Voltage levels (already did this) Check Z104 pins 1,3,4,11,13 for correct waveforms Replace as needed: Z101, Z103, Z104, Q102, Q103, Q104 Does that sound correct? Yes, that's right. Thanks!

Yep, took them all out, and the IC's.

Ooof a mistake on my part as back in the day I only had DOS 2.0 so not familiar with 2.5. In any case formatting with option P. and then trying to read it on an 810 gives the same result:the drive spins, the head moves forward then a quick back and forth a single "BEEP", then starts over. I think it does this 3 or 4 times before an ERROR 144. Cleaned, wiped with microfiber cloth: same results, unfortunately! 😕 Doesn't seem to help! Same results; won't read for checking directory and won't finish the format.😕 BTW Thank you for helping so far! Dukester

Sorry! Yes it does advance the head. Here is a video of it powering on and then after a disk is inserted, trying to boot from it: Ok, for formatting, I think mine starts at 0 and goes to 39 (maybe), but it never gets does anything else after this except spin: Atari 810 format attempt I took a blank disk, formatted it in my working 1050. Then I wrote DOS files to it in DOS 2.5. Moved disk to 810 to try and format it and the format never completes. Eventually it stops spinning and gives an ERROR 138.14 Then I move the disk to the 1050 and try to read it and get an ERROR 144. Formatted in a 1050, when moved to the 810, and I try to read it in DOS 2.5 using disk directory, the drive spins, the head moves forward then back, and I get a single "BEEP", then starts over. I have to hit BREAK to stop it. I tried this a couple of times and it varies between the spinning never stopping and sometimes it stopping with an ERROR 144: i tried a couple of different RPM test utilities and none worked. Almost all spun the 810 drive, the head moves forward then back (just like previous example), then a single "BEEP", repeats, and eventually ERROR 144.

Hey gang, I have a Tandon Atari 810 drive that I can't get to read or write from. Things that the drive does: Powers on LED lights come on Busy light comes on & motor spins Busy light & motor go off after short period (power on Atari computer) Motor spins "BOOT ERROR" (for any good disk that work in a 1050 Things I've tried Setting the 810 as D2 and trying to format a single density disk. (Drive spins. Head advances bit by bit and then the motor spins & spins & spins forever until I hit BREAK whereupon: ERROR 128. I have to physically power off drive to get it to stop spinning.) (A) Disk directory of known good disk from DOS 2.5. (Drive spins & spins & spins. Head retracts & advances a few times. Then: ERROR 144) I picked this drive up off that big auction site and when I got it and it wouldn't boot or format, it sounded like the speed of the drive was too fast. I screwed up and started trying to adjust the speed on it. I tried several RPM utilities and while the drive will respond to the command of checking the speed from the program (it spins), that is all it does. No speed is displayed in any of the utilities, and I either get an ERROR 139 or ERROR 128, depending on the utility. (I've tried: SPARTA-DOS, Disk-Doctor-II, Disk_Wizard_II). I'm thinking no communication is getting back to the Atari computer but I am new at this so not really sure. Other things I've checked and neglected to mention above: Checked power from power supply (good) Checked board voltages (good) Reseated all IC's, reseated them again (no difference) Tools I have: FujiNet DMM Logic probe Digital scope I have both an 800 and an 800XL to work with from the computer side and I've been looking for a good 810 to swap parts with but haven't had any luck so far finding a matching, working one. Where do I go from here troubleshooting? (I know I shouldn't have messed with the speed! 🙄) Thanks Dukester

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I don't have a good track record getting the bigger chips out without bending pins but I did ok on this one and you are correct, it's just the GTIA. It's weird to me that it functions for the most part; I thought it would be all or nothing. Any sources for replacements? I see one on that bidding site but hoped to find one a little less expensive. Cheers Dukester

Hey folks, I have a weird issue with I think the GTIA chip in my 800. Three of the console buttons do not work:: Start/Select/Option. System Reset does work, which I think is on the A302 chip. Swapping the CPU board out with one from a 400, the console keys work again. Another odd thing is that with the bad GTIA, the in-store demo cart starts up fine with the multicolor logo but then immediately jumps into the "Want to know more" screen instead of the "What to expect from your Atari computer", like it is seeing a keystroke signal without one being pressed. So my 2 questions are, is this almost certainly a bad GTIA chip only (but not completely bad) and not an issue with another chip/capacitor/resistor in front of the GTIA? are there any sources for replacement GTIA's? I don't see them listed in Best's volume 10 addendum. Admittedly I haven't called to see if they have any. I don't think I can pony up for a Sophia upgrade right now. Thank you Dukester

Mod, please delete. I am having trouble getting my reply to the correct thread. Posting from my phone so that may be the issue. Apologies!

Wrong thread, ignore my post.

So my broken GW monitor took direct S-video connection and the only other way I have connected my 800 is to a CRT TV via RF adapter. What is the appropriate method for connecting to modern LCD monitors without S-video connectors? Some kind of adapter to go from a Hercules cable to HDMI/composite/VGA? cheers Dukester