Dead 65XE

[Tezz]

Hey again all Well, I tested the 65XE's that came today and two worked and one is DOA The dead XE looks as though it's been stored possibly out in a shed or garage as it looks like it's been exposed to the ellements. The shielding has a small amount of surface rust but everything on the PCB looks ok visually. The XE powers on and the LED lights but I get no signal with the RF tv output. I've not got my monitor/scart connector here to test it with but I'm pretty sure that the XE is faulty anyway. When it's switched on, the output is just a black screen. Much has been discussed about the poor build of the XEs so it's no great surprise that one arrived dead. Where would be the best place to check on the PCB for faults? If I can I test with a multimeter to see if there are any bad connections, where do I start? and, what's best to check out first? I hope to rescue this one... the 800XL's will arrive anytime too.

 

Regards,

Tezz

[Tezz]

Oops, I remembered this thread recently

 

http://www.atariage.com/forums/index.php?s...c=97438&hl=

 

Any other advice would be good however

[Tezz]

OK I've hit a snag .. Where in the UK can I get 4164 DRAM or 41256 DRAM's ??? I'm all for saving another XE from the scrap heap but I can only find them listed in the US. With cost of shipping to the UK, I can buy more working XE's. It's a shame not to reserrect it when the mem chips only cost a few cents (or pence) to buy. I don't mind spending the time diagnosing and eventually desoldering and replacing the chips etc...

 

One question though... Can I check that it is actually the RAM that's at fault? What can I do to test this? Can I check connections with a multimeter? Does anyone have any advice on progressing with a diagnosis, any help will be much apreciated.

 

I'll post my findings here incase it helps anyone else out looking to repair.

 

Regards,

Tezz

 

Here's a photo of the PCB. I airblasted it and cleaned it out this afternoon ready to repair.

Edited March 1, 2007 by Tezz

[+Mitch]

Well, if you don't mind desoldering you could unsolder and socket all of the RAM chips. Then switch the RAM chips from the lower 64k with the RAM chips from the upper 64K and see if it will boot. Of course, if you have several bad RAM chips that won't tell you much but it may help you isolate which chip is bad.

 

Mitch

[Gunstar]

OK I've hit a snag .. Where in the UK can I get 4164 DRAM or 41256 DRAM's ??? I'm all for saving another XE from the scrap heap but I can only find them listed in the US. With cost of shipping to the UK, I can buy more working XE's. It's a shame not to reserrect it when the mem chips only cost a few cents (or pence) to buy. I don't mind spending the time diagnosing and eventually desoldering and replacing the chips etc...

 

One question though... Can I check that it is actually the RAM that's at fault? What can I do to test this? Can I check connections with a multimeter? Does anyone have any advice on progressing with a diagnosis, any help will be much apreciated.

 

I'll post my findings here incase it helps anyone else out looking to repair.

 

Regards,

Tezz

 

Here's a photo of the PCB. I airblasted it and cleaned it out this afternoon ready to repair.

 

Hey! That's an instant 130 65XE model there in the picture! If you are going to be replacing ram chips anyway, just add in the other 8 in those empty chip slots (might as well install chip sockets), and maybe one or two other components and you'll have a working 128K machine!

 

Do a search in the 8-bit section, it should turn up the needed info. I remember a guy from South America somewhere, who had the same 130 motherboard in his 65XE, about 6 months or a year ago who upgraded his 65XE to 128k.

Edited March 1, 2007 by Gunstar

[+Mitch]

Duh, I'm an idiot, I was thinking that was a 130XE. Ignore what I said about swapping the RAM and go with Gunstar's advice.

 

Mitch

[Gunstar]

You should open up those two working 65XE's and see if they have the original 65XE motherboards or the later 130XE MOBO with half ram.

 

New thought: Do the 65XE's with 130XE MOBO's have the expansion port on the back?

Edited March 1, 2007 by Gunstar

[Tezz]

Hey! That's an instant 130 65XE model there in the picture! If you are going to be replacing ram chips anyway, just add in the other 8 in those empty chip slots (might as well install chip sockets), and maybe one or two other components and you'll have a working 128K machine!

 

Do a search in the 8-bit section, it should turn up the needed info. I remember a guy from South America somewhere, who had the same 130 motherboard in his 65XE, about 6 months or a year ago who upgraded his 65XE to 128k.

That's cool I was gonna update it to 320k. whats the best way anyway to check which of the ram (if any) is faulty ? I've got a dead 800xl, are they socketed in the 800xl so i can unplug and piggy back them in the xe to bypass the bad ones? is that easy to do?

[Tezz]

You should open up those two working 65XE's and see if they have the original 65XE motherboards or the later 130XE MOBO with half ram.

 

New thought: Do the 65XE's with 130XE MOBO's have the expansion port on the back?

I just checked the three 65XE's and they all have the expansion port I've only opened up and partially cleaned the faulty one so far but I would guess they all have 130XE boards in there. I'll check out the ram from the dead 800xl in the morning and see if I can get the faulty XE booting and hopefully I can then source a bunch of ram chips to get all three up to 128k or expanded further to 320k. I read a post by MetalGuy about getting increased ram chips and utilising the unused banks by adding the Atari custom memory control chip in a particular way. That seems like a good idea as I'm gonna need to buy the Drams to replace anyway so it'll be a worthwhile expense overall to have them upgraded fully in the process.

 

Hopefully can identify the bad RAM (if thats what the problem is)

 

Regards,

Tezz

[mimo]

OK I've hit a snag .. Where in the UK can I get 4164 DRAM or 41256 DRAM's ???

could try here chips

[Tezz]

OK I've hit a snag .. Where in the UK can I get 4164 DRAM or 41256 DRAM's ???

could try here chips

Brilliant, thanks again

[Tezz]

Hey all. I need some advice about testing whether the memory is faulty on the XE..

 

As they are socketed, I've taken the RAM from a dead 800xl and want to "piggyback" them on the RAM in the XE which I think is at fault. The thing is I'm not sure exactly how to do this? Do I need to just litterally place the ram on top of the other one and touch pin to pin? Or, do I need to spend hours removing (desoldering) the original ram and fitting ic sockets just to test it out? I've heard about piggybacking ram to determine which ones are faulty but after a search around Google I've not found any guides about how to do this. Any advice would be appreciated. BTW I'm not sure why the 800XL is dead but the dram is supposed to be solid on the XL so I should be ok to use the RAM to bring the XE back from the dead

Edited March 2, 2007 by Tezz

[classics]

As they are socketed, I've taken the RAM from a dead 800xl and want to "piggyback" them on the RAM in the XE which I think is at fault. The thing is I'm not sure exactly how to do this? Do I need to just litterally place the ram on top of the other one and touch pin to pin? Or, do I need to spend hours removing (desoldering) the original ram and fitting ic sockets just to test it out? I've heard about piggybacking ram to determine which ones are faulty but after a search around Google I've not found any guides about how to do this. Any advice would be appreciated. BTW I'm not sure why the 800XL is dead but the dram is supposed to be solid on the XL so I should be ok to use the RAM to bring the XE back from the dead

 

Just place another DRAM on top, making sure every pin is making good contact. You may have to bend the pins on the top dram inward slightly to get a tight fit.

 

This works more often than not because most dram fails 'open'.

 

Steve

[Tezz]

Just place another DRAM on top, making sure every pin is making good contact. You may have to bend the pins on the top dram inward slightly to get a tight fit.

 

This works more often than not because most dram fails 'open'.

 

Steve

OK thanks, I've fitted all of the ram chips over the top of the xe ones but it's still dead. The ram chips from the 800xl has HM4864P-2 Printed on them. Is this ok over the 4164 chips? should i only be trying one chip at a time and not all of them at once?

[mimo]

Hey all. I need some advice about testing whether the memory is faulty on the XE..

 

As they are socketed, I've taken the RAM from a dead 800xl and want to "piggyback" them on the RAM in the XE which I think is at fault. The thing is I'm not sure exactly how to do this? Do I need to just litterally place the ram on top of the other one and touch pin to pin? Or, do I need to spend hours removing (desoldering) the original ram and fitting ic sockets just to test it out? I've heard about piggybacking ram to determine which ones are faulty but after a search around Google I've not found any guides about how to do this. Any advice would be appreciated. BTW I'm not sure why the 800XL is dead but the dram is supposed to be solid on the XL so I should be ok to use the RAM to bring the XE back from the dead

Save the XL

[Tezz]

Well, It seems maybe the XE has other problems, piggybacking the ram chips from the 800xl didn't revive it although I'm not sure about the type of ram (HM4864P-2) that was in the 800xl. and whether that was ok on top of the XE's 4164 chips? The doner XL is dead too so that could be a ram prob too. I guess I'll have to wait for my other 4 800xls to arrive and borrow the ram from a working one to test the xe properly. I have a mint 800xl here which I've had since 1985 but I don't really wanna touch that. Oh well, I guess time will tell if the XE's problems lie elsewhere... After testing the RAM I'll work my way through testing the other components on the board.

Edited March 2, 2007 by Tezz

[ataridano]

If it's been exposed to the elements, check all the socketed chips/parts and make sure all the contacts are good. Also check for any moisture damage to the traces on the board, clean anything that looks like it needs it. Beyond that, and swapping out any socketed chips you might have (just because that's easy enough to do), it might take a 'scope to go any further. I hope you're able to save it!

[Tezz]

If it's been exposed to the elements, check all the socketed chips/parts and make sure all the contacts are good. Also check for any moisture damage to the traces on the board, clean anything that looks like it needs it. Beyond that, and swapping out any socketed chips you might have (just because that's easy enough to do), it might take a 'scope to go any further. I hope you're able to save it!

Thanks, I'll have a thorough look at the pcb and see if i can spot anything. It looks in good condition overall so I'm sure it'll be ok

[Tezz]

Hey all, well, progress so far on the 65XE's..... I seem to have half this thread in the "Dead 130XE" post http://www.atariage.com/forums/index.php?showtopic=97438 .. so i'll post back into my original thread...

 

Anyway... progress so far.. I'm still waiting for my 41256 memory chips to arrive to start the upgrade and repair. To recap, 2 of the 3 65XE's (which were actually 130XE mobos with 64k installed) worked and one didn't. I intend to "carefully" desolder the ram from one of the working XE's and install that machine completely with the 41256's and then do the 320k upgrade. With the original working ram chips that I have removed, I'll piggyback on the dead XE's RAM and hopefully it will then boot. If it works, I'll install IC sockets on all 16 rows put the orginal working ram chips into the first 64k row and then order 16 more 41256's which will enable me to fill the other 2 XE's and achive 3 320k machines...

 

I've completed restoring the first XE's case with grey enamel spray which went very well. The XE's were in a pretty sorry state when they arrived and the keyboards were not just yellow, they were shot to pieces so I'm waiting to hear back for 3 replacements.

 

Here's a couple of photos of the first newly cleaned and painted case before it's re-assembled. I'll post some before shots later on. Appologies for the quality, I took them quickly with my phone this morning.

 

Regards,

Tezz

[Gunstar]

Looks like you did an outatanding job painting it, and found a good color of grey. It looks great. It will look even better if those replacement keyboards are new/unyellowed. I replaced the keyboard with one from Best E. they sell them for $30-40 I think, but it's worth it to have new keyboards.

[Tezz]

Looks like you did an outatanding job painting it, and found a good color of grey. It looks great. It will look even better if those replacement keyboards are new/unyellowed. I replaced the keyboard with one from Best E. they sell them for $30-40 I think, but it's worth it to have new keyboards.

Thanks, I took your advice and used an interior/exterior grey enamel primer. It was a US branded spray made for plastics. The resulting colour was closer than I expected it to be... I've ordered 3 new keyboards from a guy over here in the UK but I'm still waiting to hear if they're in stock, hopefully so as the memory and other components should arrive any time now.

 

Tezz

[Urchlay]

Hm, every time I've tried to spray-paint a plastic computer case, I end up with bits of it flaking off for months... what kind of paint do you use to get it to "stick" to the plastic? Do you have to rough up the plastic with sandpaper or something before spraying?

 

I dream of owning an all-black XEGS (well, except I wouldn't try to paint the keys on the keyboard)...

[mimo]

[quote name='Urchlay' date='Fri Mar 9, 2007 5:14 PM' post='1253492'

 

I dream of owning an all-black XEGS (well, except I wouldn't try to paint the keys on the keyboard)...

Why not, very stealth

[Urchlay]

 

I dream of owning an all-black XEGS (well, except I wouldn't try to paint the keys on the keyboard)...

Why not, very stealth

 

I don't know if I could get all those keys off the keyboard without breaking anything... also the keyboard layout on an Atari is non-standard enough that I'd go crazy if I couldn't look and see the key labels, so I couldn't just spray them black, I'd have to put white decals or something on them (no way would I attempt to actually paint letters/numbers/etc on there by hand!)

 

On good PC keyboard (IBM Model M), I don't need the key labels... in fact, they come off (they're separate pieces from the actual keys), and I taught myself how to touch type by removing all the caps from my good keyboard (leaving only plain grey keys). I cussed a lot for the first 2 weeks, but after a month I was able to touch type with 99.9% accuracy at maybe 60 words/minute. The down side of this is that I have a hard time adapting to any other keyboard (like the Atari ones)...

[Gunstar]

Hm, every time I've tried to spray-paint a plastic computer case, I end up with bits of it flaking off for months... what kind of paint do you use to get it to "stick" to the plastic? Do you have to rough up the plastic with sandpaper or something before spraying?

 

I dream of owning an all-black XEGS (well, except I wouldn't try to paint the keys on the keyboard)...

 

You are either using the completely wrong kind of paint, or the surface you are painting is not completely clean, or you are applying additional coats of paint outside the specified window of opportunity (as specified on the paint can), generally additional coats of paint need to be applied within 20-30 minutes, or after 24 hours. It should be an enamel paint that is made for plastic, most interior exterior enamel spray paints will say on the can if it is made for plastic. Most are actually multiple surface paints that will include metal, wood and plastic. Most importantly to avoid dripping, peeling or the "raisin wrinkle" effect the paint must be applied at the correct distance from the surface and with multiple, CONSERVATIVE coats of paint (gerenally for me, it takes a minimum of 3 coats just to completely cover the bare surface). Too many coats is bad to becuase the paint will be too thick, which leads to the "soft areas" where a fingerprint can be left, engraved on the surface and it will never completely dry right and lead to peeling, and last but not least, you will lose the original texture of the plastic surface which you want to maitain if your attempting a restoration. you NEVER want to sand the surface with sandpaper or steel wool, to get the paint to "stick" as this ruins the surface and the textured plastic surface is already enough for a quality paint to adhere too. These aren't pieces of wooden furnature.

 

Also, there's not much use in repainting a keyboard, firstly, there's the problem of covering the letters and symbols and will be a pain to handpaint and never will look original, decals will wear out or peel off, and the paint itself, no matter how good of quality, will wear off from constant contact with your little fingers. Either just clean and repair the keyboard as best as possible(which may me taking each key off one by one and cleaning it and underneath) and live with any discoloring from light, or replace the keyboard.

 

Lastly, but stuff that should be done first, for a professional job, you need to do it professionally in the sense of removing any name plates or carefully covering them along with stuff like the rubber feet and cover any bottom decals or plates as well, they can be uncovered or reattached when all else is done. every crevice should have been cleaned of dust, dirt and grime, and the entire case cleaned well with a strong cleaning spray. Obviously you should be doing all of this with the case completely removed from the computer.

 

It does take some skill to do a proper paint job, that's why there are professionals. If you have not done it before, or have done poor jobs, practice painting on something else until you learn to apply smooth, even, multiple coats of paint that looks perfect. Patience is a key as well.

Edited March 10, 2007 by Gunstar