800XL nonfunctional.

[darthkur]

I recently acquired an 800XL along with a 410 tape machine, 1050 disk drive, manuals and four carts. Sadly the XL appears to be fried and the 410 does nothing but move in rewind and that only when I twisted the right hand capstan in the correct direction for a while. Unfortunately it didn't help doing that for either Play or Fast Forward. The real disappointment, obviously, is the failure of the computer itself. It will power up as indicated by the red l.e.d. coming on but the only image produced on screen is a dark gray field with white moving diagonal lines. I got the same results with both a monitor and a television. I decided to disassemble the unit to see if I could discern any obvious defects. I couldn't find anything like a lose diode, broken solder or chip that wasn't fully inserted. I powered it up while still apart to see if any of the chips would heat up abnormally to indicate fault only to find that the screen is now just plain black. Pressing reset or any other key for that matter has no effect at all.

Is there any hope in saving this computer or is it irreparably damaged? Perhaps even more so due to my inept meanderings.

Edited May 11, 2007 by darthkur

[mimo]

I dont know about the XL, but the 410 wont play unless the computer 'tells' it to. So dont write it off yet.

by the way, I wish mine would re-wind!

[Rybags]

Does the screen display change if you hold down RESET ?

 

At least it's generating something resembling a display, so not all hope is lost.

 

Are the chips socketed - if so, push each one down gently.

 

Not sure about the tape drive - maybe a broken belt.

[Allas]

Well, where you turn on the Atari and get green screen, means is many or one damaged chip inside.

 

It could be a memory chip (8 little chip at the left side of the mainboard) or a main chip (4 chips at the bottom of the mainboard).

That's a fact. As you see, its really very difficult the plaque mainboard is damaged. So we have to concentrate in the chips.

 

- First, the big bottom chips are GTIA, ANTIC, 6502, PIA, in this order. You should see if are socketed. If it is yes, you should replacing from another chips from other working Atari XL or XE. If it is not, the bad luck, because you have to remove the chip and replacing with sockets.

 

- After replacing the big chips and still not working. Then the problem is with memory chips. You have to desoldering the 8 memory chips and replacing with good chips.

 

If you buy your Atari in ebay, i only said that only people that say the computer works fine, passed the internal tests and show the READY on screen is a guarantee the computer works fine. Don't believe in people who said "Atari is working fine because the red led turn on", its 99.99% a trick to steal your money.

[darthkur]

Nothing happens when any key is depressed. At least it didn't before I took everything apart. The computer is still in pieces at the moment. I was hoping to possibly get a few suggestions on what else I might try to look for while it was still easy to get at. The chips were all seated too. I even pressed on them all just in case. None of them moved a millimeter. Unfortunately I do not have another XL so there's no extra parts to swap out. I imagine that it'd be more of a task and expense to obtain extra chip than it would to get another computer all together.

Edited May 12, 2007 by darthkur

[walter_J64bit]

Nothing happens when any key is depressed. At least it didn't before I took everything apart. The computer is still in pieces at the moment. I was hoping to possibly get a few suggestions on what else I might try to look for while it was still easy to get at. The chips were all seated too. I even pressed on them all just in case. None of them moved a millimeter. Unfortunately I do not have another XL so there's no extra parts to swap out. I imagine that it'd be more of a task and expense to obtain extra chip than it would to get another computer all together.

I'll be happy to take that 800XL off your hands PM me.

[Urchlay]

I dont know about the XL, but the 410 wont play unless the computer 'tells' it to. So dont write it off yet.

by the way, I wish mine would re-wind!

 

It won't play without the computer, but it should at least rewind and fast-forward, and you shouldn't have to be turning the spindle with your fingers to get it started, either.

 

Most likely, the belt is not actually broken, but has a nasty kink in it from sitting in the same place for many years (and/or the rubber is rotting away).

 

Probably you're not concerned with the 410 until after you get the computer working, but when you get ready to fix the 410, see this thread:

 

http://www.atariage.com/forums/index.php?showtopic=105976

 

Near the bottom of the thread are the measurements and part numbers for a replacement belt. That plus maybe a good cleaning with rubbing alcohol should get your 410 back in working condition.

Edited May 12, 2007 by Urchlay

[Fujix]

Take out the chips one by one, clean and reseat them, touching your fingertips against a piece of tinfoil first to rid them of any static charge and trying the machine after each. Use a chip removing tool (cheap) or else a small flat-bladed screwdriver, prying up each end a little in turn using a kind of sideways 'rolling' motion of the blade to apply controlled pressure.

 

Use a proprietary contact cleaner (no use recommending one, I'm in the UK and it'll be different for you ) to clean the pins (or a soft rubber).

 

If that doesn't work the only way to locate the faulty component(s) if you don't have an oscilloscope and the tech notes (a good, free PC-based oscilloscope called WinScope is available from http://mywebpages.comcast.net/fel4u/oscope/winscope.htm among other sites) is to replace them one by one from another, working machine (I note you said you don't have one currently but presumably you still want to acquire one?).

 

Start with the CPU -- that's what it sounds like to me. I bought an 800XL from a table sale for the princely sum of 50p (about a dollar) and of course it didn't work. Had a lovely clicky keyboard though and I was determined to make it work. Screen 'display' was much as yours which led me first to the ancilliary/display components...WRONG! As soon as I swapped out the 6502 (with one I desoldered off a damaged 130XE board) Hey Presto! working XL. That was 13 years ago, it's still working today.

 

Good luck!

[darthkur]

Thanks for the info everyone. I'll definitely try removing and cleaning the chips and see if that works. If not then I'll have to wait until I acquire another unit.

[Ross PK]

If you get a new one don't chuck your nonfunctional one, just keep it for spares.

[Mr.Amiga500]

I have the same problem. I bought an 800XL off eBay and the description said that it "powered on", but they didn't have the cable to connect to TV and fully test it. I thought as long as it "powered on", it'd be fine. I plugged it in and nothing happened. So I bought a second 800XL and tried the power supply from that one in the first 800XL. The light came on, but the screen stayed black with vertical interference bars. So that means that the seller lied. The power supply and the computer were dead and it couldn't possibly have "powered on". It's a pity because the 800XL is in excellent shape. Maybe it's in excellent shape because a dead computer doesn't get much wear from use.

 

I opened it, checked that all the chips were seated and so on. I guess the only way to find out what's wrong is to swap chips with my working 800XL, but I'm too scared of breaking the pins. Chips usually come out with a jerk which bends the pins and when you bend them back, they break.

 

My "working" 800XL has a weird tint problem where I have to turn the TV's tint way down to get the right colours.

[Tezz]

I'm too scared of breaking the pins. Chips usually come out with a jerk which bends the pins and when you bend them back, they break.

Don't be worried about removing the chips from their sockets, they're not that easily damaged. Just make sure that you remove them and also reinsert them evenly. You can use an ic removal tool which basically hooks onto each side of the ic so that it gives even force when it's removed. Even if you bend some pins, they should bend back straight again without breaking. The ic legs can take quite a bit of abuse before they break so if you're careful you should have no worries at all.... As always the ram chips should be your first port of call, you will prob find that is where the fault is. 3 out of 5 of the 800xl's i've recently repaired which were doa were just simply a few bad ram chips. If you're lucky you will have a socketed mobo. most of mine were not so it's desoldering time in that case... either way if your xl is in good shape and you didn't pay too much for it in the first place when the seller mis-sold it you, you'll have yourself a mint machine in no time. Good luck

[+kheller2]

My "working" 800XL has a weird tint problem where I have to turn the TV's tint way down to get the right colours.

 

Adjust the color pot wheel until the colors are correct. That is the little hole on the bottom of the XL, insert a plastic flat tip into there and turn, or open the case and turn the dial by hand.

[+bf2k+]

I got an 800xl last week that has a weird problem... the PBI port seems to be messed up. I get intermittant errors when try to boot from a HD thru the MIO. This HD/MIO setup works flawlessly on my other 800xl here as wel as on a 130xe I have laying around.

 

Sometime I get slow BOOT ERRORS, sometime a SpartaDOS "No Dos" error, sometimes error 138's and 139's - real intermittant stuff like maybe the cable connections are bad. I have cleaned the 800xl PBI connector and since the MIO/HD works fine on my other computers, I am 99% sure the problem lies with the new 800XL. Since this new XL is a beautiful machine, maybe I'll transplant my old "working" Rambo XL into the nice case and keep the rest for parts.... but I'd really like to get the new XL working.

 

Any ideas out there

[darthkur]

If you get a new one don't chuck your nonfunctional one, just keep it for spares.

 

No need to worry. I seldom ever throw away anything. The cluttered condition of my entire house is testimony to that.

[Mr.Amiga500]

Adjust the color pot wheel until the colors are correct. That is the little hole on the bottom of the XL, insert a plastic flat tip into there and turn, or open the case and turn the dial by hand.

 

Thanks for the tip! I was wondering what that little thing was. I'll test it when I get a chance. I noticed that the tint doesn't stay consistent, but occasionally flips back and forth. Maybe I've got a loose connection on that wheel. At least now I know where to look.

 

Don't be worried about removing the chips from their sockets, they're not that easily damaged. Just make sure that you remove them and also reinsert them evenly. You can use an ic removal tool which basically hooks onto each side of the ic so that it gives even force when it's removed. Even if you bend some pins, they should bend back straight again without breaking. The ic legs can take quite a bit of abuse before they break so if you're careful you should have no worries at all....

 

Well Atari chips must be sturdier than Amiga chips because about half of the socketed Amiga chips I removed got their pins warped. I was being extremely careful and I had an IC puller. No matter how carefully I bent the pins back into shape, some still broke or were too weakened ever to remove again without breaking. I tried different methods too - slow enough to make a three-toed sloth look fast, the "gentle wiggle", the fast vertical pull. Results were always the same.

[Tezz]

... Atari chips must be sturdier than Amiga chips because about half of the socketed Amiga chips I removed got their pins warped. I was being extremely careful and I had an IC puller. No matter how carefully I bent the pins back into shape, some still broke or were too weakened ever to remove again without breaking. I tried different methods too - slow enough to make a three-toed sloth look fast, the "gentle wiggle", the fast vertical pull. Results were always the same.

That's surprising to hear, certainly the Atari IC's are more sturdy in that case. I've bent the legs badly several times in the past when rushing swapping ic's to determine faults. I guess the Amiga's are more fragile. I've heavily modified my Amiga 1200 over the years but i've never removed any ic's from the board to compare. I asked a guy at the electronics store how many times they can be bent (in general) before breaking and he just said a good many times like 10 bends or so back and forth and this was why they sold ic leg straightners ... I didn't take that advice seriously but it goes to show the difference of opinion (or degree of knowledge) when questioning.

 

You should find working with the Atari ICs no problem, I have so far. Good luck with your repair.

Edited May 13, 2007 by Tezz

[Mister VCS]

I have the same problem. I bought an 800XL off eBay and the description said that it "powered on", but they didn't have the cable to connect to TV and fully test it. I thought as long as it "powered on", it'd be fine. I plugged it in and nothing happened. So I bought a second 800XL and tried the power supply from that one in the first 800XL. The light came on, but the screen stayed black with vertical interference bars. So that means that the seller lied. The power supply and the computer were dead and it couldn't possibly have "powered on". It's a pity because the 800XL is in excellent shape. Maybe it's in excellent shape because a dead computer doesn't get much wear from use.

 

I opened it, checked that all the chips were seated and so on. I guess the only way to find out what's wrong is to swap chips with my working 800XL, but I'm too scared of breaking the pins. Chips usually come out with a jerk which bends the pins and when you bend them back, they break.

 

My "working" 800XL has a weird tint problem where I have to turn the TV's tint way down to get the right colours.

 

Similar problem with an Atari 600 XL PAL here. I bought it from ebay and the description said that it "powered on". The TV-connection-cable was missing. I connected the XL with an Atari 2600 JR cable to my TV-set. After "Power On" i got a red screen. Pressing any key has no effect. I think the PSU is o.k., but the XL is dead....

 

Any ideas?

Edited March 18, 2010 by Mister VCS

[flashjazzcat]

Similar problem with an Atari 600 XL PAL here. I bought it from ebay and the description said that it "powered on". The TV-connection-cable was missing. I connected the XL with an Atari 2600 JR cable to my TV-set. After "Power On" i got a red screen. Pressing any key has no effect. I think the PSU is o.k., but the XL is dead....

 

Any ideas?

Red screen at boot can mean a bad OS ROM. Check it's seated properly (assuming it's socketed).