Atari 800XE: Red Screen and hot ICs

[dex]

Hello everybody I'm new in this forums. I've registered some months ago as I've received the Harmony Cartdrige for my Atari 2600 to say thank you but that was all so far. I hope my English is not too bad I will try to do my best you can understand me. Unfortunately I'm not a native English speaker.

 

A week ago I got an Atari 800XE without anything – no power supply, no cables, no drive. It was sold as "untested". Well I'm not sure if this is true because I've opened it and found some human hair inside. But that's OK, I expected that. Unfortunately – after buying a power supply and connecting the Atari to my TV – it's showing only a red screen. I asked Google what kind of problem this could be and it told me I'm an idiot buying this stuff as "untested" and believing it could work. A red screen seems to be a problem with some components inside (ICs/chips).

 

Anyway, it's the first time after round about 30 years I own a machine like this again. In the past my brother and me we got an Atari 65XE from our parents – I was 5 years old. Or let me explain this another way: I really don't have a clue what to do now!

 

The case and the keyboard are looking pretty good. So I thought the board should be untouched but after I opened the case and removed the metall shell I've found two places on the board looking a little bit strange to me. The photo with the blue and the yellow cable soldered to the ICs looks to me like a DIY solution for I don't know what. The other photo shows three resistors soldered to U34. This looks pretty ugly. Am I right or is this just a usual and untouched board?

 

I've also turned the Atari on for about 10 minutes and checked the temperature of the chips with my finger tips. Yes I know, this is not very professional. All chips seem to be cold or warm except two memory chips (the second and the third from the bottom), they are getting f...really hot! There is another chip I don't really know if its temperature is OK. It's the one on the top near the expansion port "CO14806-12". Is this the CPU? Its getting hot when I put my finger on the left side of the chip after about two or three seconds but I would say the IC is not all the time hot and it's not getting really hot when I touch it on the right side.

 

I tried also to make photo of the board back but I'll do this better tomorrow in the day light. There are too many reflections and so it looks terrible. The five pins of the RF modulator look like somebody tried to solder there something for a reason with too much heat. I hope I can take a photo of this tomorrow.

 

If you need more informations or photos, please let me know. What I would now like to know from you is whether there is a chance to rescue the Atari or not? And if there is a chance what should I replace? Only the memory or even more chips? What about the capacitors? I think these capacitors shouldn't leak and destroy anything but maybe they are too old and could also cause problems?

 

And just because I'm curious: What is the IC at the bottom left "CO61991-01" for? Google tells me this is "Freddie". But what is this chip for and why is this the only one which is on a socket?

Edited November 18, 2017 by dex

[Level42]

Welkome. My native language isnt English either but you do very well I think. Where are you from ?

 

You could have looked around some recent threads here....there are plenty of similar threads....but anyway:

You have mT RAM there. They are know to be dead....although there are exceptions....

Replace at least the hot ones and see what happens. If you want to bullet proof, replace all.

 

I google didnt tell you what FREDDIE is, you googled wrong.

google ATARI FREDDIE and you,lol find the answer.

 

I find XE with several,different chips sometimes socketed. Not sure if they were earlier repairs are maybe even factory repairs.

 

Ive seen plenty of XE with those dirty wire mods, those are factory. Leave them.

Edited November 18, 2017 by Level42

[_The Doctor__]

yep just replace the all the ram( on the left side and since your already there... finish adding 8 more right of it, there are threads for the upgrade... then you'll have an 800XE that's back to being a 130XE... twice the memory!

[Level42]

Personally I would invest some money in getting a U1MB instead of upgrading it to just 130XE level. Going 130XE will require 8 more sockets and RAM chips and also a MMU and a socket for it. Granted, youll get rid of those three jumpers (they're zero ohm "resistors") if that bothers you....

But the money and time saved on those and getting a U1MB instead will open the door to every possible RAM configuration possible up to 1MB plus 4OS ROM slots and even more cool stuff.....

And also order a stereo POKEy board.....

Edited November 18, 2017 by Level42

[BillC]

yep just replace the all the ram( on the left side and since your already there... finish adding 8 more right of it, there are threads for the upgrade... then you'll have an 800XE that's back to being a 130XE... twice the memory!

A 130XE MMU to replace the resistors in U34 is also required for the upgrade to 128kB.

 

Another alternative would be to install a U1MB after he gets it working at 64kB, this would require sockets for U34(MMU) and the OS chip(which is the NCR 23128-30 PROM in the middle of the PCB). This upgrade removes the need for a MMU chip since this function is part of the U1MB.

[Level42]

Isn't that exactly what I wrote ?

[Keatah]

One step at a time. Get the machine working and tested with diagnostics. Then move on to upgrading.

[_The Doctor__]

I am a silly sort and prefer to do it so that it's a 130XE again and then add upgrades, that way when something fails like the ultimate 1 meg etc etc, I still can easily have a useful computer till it's replaced or repaired..

[Level42]

It never was a 130XE so how can it be a 130XE "again" ?

Edited November 18, 2017 by Level42

[_The Doctor__]

it's 800XE, basically a 130XE crippled/downgraded to be an 800XL with eci.... but you knew that already

Edited November 18, 2017 by _The Doctor__

[Level42]

Yep.

 

So making it a 130XE _is_ an upgrade :D

 

Man...let's get this thing running first....I wonder what those vertical stripes are on the left of the screen. I've seen plenty of red screens....but not those stripes too....

Edited November 18, 2017 by Level42

[+kheller2]

Dex, your English is better than a lot of native English writers. At least in the USA.

[Level42]

I always say: My English is a lot better than your Dutch.

 

That usually silences anyone commenting on my English :D

[+Stephen]

Don't ever apologize for having bad english. None of the native speakers give a damn about spelling or grammar these days. It's always also been a case of nobody over in the USA wanting to learn any other language. I am guilty of it myself. Laziness I guess.

[Level42]

Yeah but then again....English is a nice and easy language to learn. And we've been exposed to it from when we were kids in this little country. We don't have the speech replaced on TV series and films like the Germans do. That's why we hear English from TV and movies from pretty early. This gives is a head start. Even so....some Dutchies are horrible in English.....but let's not derail the thread

Edited November 19, 2017 by Level42

[dex]

Hello again!

 

Thank you all for your replies. And I'm happy that my English is not too bad.

 

@Level42: I'm from Poland but I'm living since 1991 (when I was 7) in Germany.

 

 

First I would like to fix the problem with the red screen (if it's possible) and than I will think about upgrading the Atari. I've already looked on Lotharek.pl, there are many fantastic expansions! I've already bought there an expansion for one of my Amiga computers. And ff I can get enough memory chips I would like not only to fix the red screen problem but also upgrade my 800XL up to 128 KByte RAM of course.

 

My only problem now is what kind of memory chips I can use and where can I get them. I would prefer to get them somewhere in Europe so I don't have to wait too long but I don't mind to order them else where.

 

I've searched in this forum and googled through the internet and as I can see there are often chips on XE boards with slower memory chips than mine. I've got some with 120 ns (?) timing but I have seen photos with slower chips on the board (150 ns and 200 ns but also faster chips with 100 ns). Am I wrong when I think it doesn't matter which timing they have?

 

And what kind of chips can I use? Are there any alternatives or do I have to use Micron Technology MT4246 chips? After searching on the internet I have found some other 64k DRAM chips with the same pinout as the MT4246. Can I use them, too? I've found this page: http://www.amiga-stuff.com/hardware/64kx1-dram.htmland checked some of the data sheets.

[Level42]

Whatever you get, do NOT ,....NOT ...NOT get any mT's !!!!

 

They are the number 1 source of dead XE's.....as your machine confirms once again. So putting them in again is not a good

Idea

 

I actually also had a few of them on stock, bought them in my arcade machine collecting days....I recently tried them....all bad.

 

On the other hand...my "main" 130XE is full (except top left position, which is never a mT....) of mT RAMs and it's a mix of -15 and -20 and that one just works fine still. But once you need to get new RAM, don't go with mT's.

 

Here's my list of compatible RAM's. -020 speed is just fine.

 

4164 RAM equivalents:

 

HM4864(A) (Hitachi)

µPD4164 (NEC)

M5K416 (Mitsubishi)

MK4564 (Mostek)

MSM3764 (OKI)

MN4164 (Matsushita)

HYB4164 (Siemens)

LH2164 (Sharp)

TMM4164(A) (Toshiba)

TMS4164 (Texas Instruments)

MB8264(A) (Fujitsu)

MT4264 (Micron) (DO NOT BUY)

MHB4164 (TESLA)

KR565RU5 (Russian)

 

 

Again....if you plan to get a U1MB, it's pretty pointless to change it into a 130XE. The second bank of RAM is doing nothing after U1MB is installed.

 

If you lack the soldering skills for the RAM work.....I recently decided to start offering A8 machine repairs......if you want you can send the machine to me, I'm in The Netherlands so shipping costs are very fair, just like the repair price....this is more kind of a hobby anyway

Edited November 19, 2017 by Level42

[dex]

Wow thank you very much!

 

I have ordered now some sockets such as 8x the MB8264A chips and 8x M3764 chips, just in case one of them won't work or to have some in case of a damage.

 

Now I got it with the U1MB memory expansion. I missunterstood this the first time.

 

I think I will try to do it myself. Not because this would cost something but I really like to solder. I have a couple of Amiga computers where I have replaced capacitors and made some small DIY electronic projects for. I think I'm not very good but I love to sit down after work, turn the radio or some music on and do some solder work. This is some kind of relaxing for me.

 

I hope this will fix the problem so I can play some of the good old games like Panther, Montezuma's Revange, River Raid, Boulder Dash, Moon Lander, ... . Emulation is nice but real hardware is not replaceable in my opinion. I will post here again to tell you if I've made it or not.

[Level42]

Totally agree about real hardware. I only use emulation for some quick testing sometimes...

 

If you only have a regular soldering station, I would Use this method:

 

- I hope you have some fine cutting pliers....cut all the legs of all the RAMs.

- remove the bodies

- take some solder and tip each and every soldering with a tiny bit of new solder so that they run again...

- put the PCB upright with the edge towards you....parts to the left side. With some pliers hold the left over pins one by one. Use a solder iron on the other side and touch pin by pin, removing the pins with the pliers.

- but the board solder side up and use either solder wick or a decent hand pump (original Soldapult are great) to clear all holes from solder.

 

 

 

It's a lot of work but as you say....it's also relaxing to do in some way

[_The Doctor__]

The price to make it a full board is so inexpensive as well as easy to do... I don't get the whole don't do it don't do it push... Every machine I've done it with has been easy as pie and costs so little why not do it.... and since mishaps to occur and add on boards come and go... why not?

 

So in my experience it's always worked out, didn't really cost anything more to do and added next to no time to accomplish.... and when your done whatever upgrades you choose with or without external memory it will always be there and be at the ready. I am a firm believer in having fail overs and back ups.... this has proven to be a wise policy...

[Level42]

I just pointed out that the extra bank of RAM will be just sitting there pretty once U1MB is installed.

 

It's 8 sockets, 8 RAM ICs (at about 1 euro each, ex. shipping), sockets....price vary....it's also 8x16=128 extra solderings....especially for someone who did just some minor soldering so far....

 

Let's say it's 15 Euro. That is already a nice step towards a U1MB

Edited November 19, 2017 by Level42

[+Stephen]

I just pointed out that the extra bank of RAM will be just sitting there pretty once U1MB is installed.

 

It's 8 sockets, 8 RAM ICs (at about 1 euro each, ex. shipping), sockets....price vary....it's also 8x16=128 extra solderings....especially for someone who did just some minor soldering so far....

 

Let's say it's 15 Euro. That is already a nice step towards a U1MB

Not to mention the extra heat, power, etc. that the 8 DRAMS will be using.

[flashjazzcat]

I'd say replace the two hot DRAMs first and see if you have a working machine before you spend any more money on it.

[_The Doctor__]

so jumping right in to a chip de-soldering and socket install and then plugging in without the experience of an easy pre run of cleaning up empty pcb slot and soldering somesockets/ chips to a get a feel for it would be of no benefit....

 

got it, the chips are cheap but omg it might hinder buying an ultimate 1 meg.... how about we fix the computer.... get some experience and then go about hacking out chips and all that

 

wow that's some pricey additional cost quoted there... I'd buy them all together and save the shipping since he's already buying 8 and you can always find the memory chips usually in socket on old graphics cards for like 3.50 usd....

 

extra heat and power?

 

For what it is worth.. same power supply and modded 320XE and Rambo XL in continuous use since the 80's sometimes without air conditioning on the 4th floor with flat black roof.... nothing died.. still using them to this day.... the things people come up with as an argument

 

Can we get back to fixing the computer and start with the ram? maybe get a feel for clearing some component through holes and soldering in some sockets before we go for the gold?

Edited November 19, 2017 by _The Doctor__

[_The Doctor__]

thanks FJC, the voice of reason....