Simon Carter Posted October 26, 2021 Share Posted October 26, 2021 Hi, usual question asking again - just bought an untested 65XE from eBay (listed as untested) and sadly it didn't surprise me by working ? I've tried the keyboard on my working XE and that's just a membrane clean/replace, so no biggie there, but turned the unit on just gives a red/burgundy screen, nothing else. Am I looking at dead RAM, or potentially replacing every IC until something works? On the plus side, i did get a copy of Yogi and the Greed Monster, so it's not all bad ? Si Quote Link to comment Share on other sites More sharing options...
mimo Posted October 26, 2021 Share Posted October 26, 2021 Personally I would replace the ram first, I bet its MT ram which if it hasn't failed will do soon ? Then see where you go from there Quote Link to comment Share on other sites More sharing options...
Simon Carter Posted October 26, 2021 Author Share Posted October 26, 2021 RAM says Sharp, not sure if that's the same as MT. Quite looking forward to seeing if I can resurrect this one Thanks Quote Link to comment Share on other sites More sharing options...
Beeblebrox Posted October 26, 2021 Share Posted October 26, 2021 (edited) @Simon Carter Good luck. You may already know this but bare in mind with the mylar/membrane you get dual and single layer ones. AFAIK and in my experience dual layer XE keyboards have lots of loose little blue rubber popper type things which all fall out upon dissasembly if you have the keyboard the wrong way. (Sorry, I don't have a pic to hand). Simius sells the dual ones for a very reasonable price if you PM him. Whereas single layer mylar/membrane XE keyboards have fixed black rubber contacts , like this when you open it up. These don't fall out: Reason I know is I have both types of XE keyboard. As mimo mentioned the red/burgandy screen is very likely a bad ram chip or maybe more. I've not heard bad things about the Sharp brand of ram chips generally. I recently ressurected a 130XE from the dead, (a rather lengthy post here details it all which may help). Plus I did the same with a 600XL with a few issues included bad ram, (red/burgandy screen). Again detailed in a rather lengthy post here. Worth bearing in mind both my machines had multiple issues aside bad ram - and yours still might. But at the start in both cases it was bad ram chips initially, (with other issues then becoming apparent). I've found, (as many other's have), that you have to fix one thing before you can work out what else needs fixing. The only PITA thing is all the RAM chips and others on the XE board are socketed. EDIT: If you haven't done already make sure you aren't using a notorious Ingot power supply to power up the XE, and IHMO get yourself a 5v USB to 5pin DIN power supply (in UK on Ebay they cost £10). Edited October 26, 2021 by Beeblebrox Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted October 26, 2021 Share Posted October 26, 2021 yeah red screen can indicate bad RAM, OS ROM, CPU, MMU. RAM is easiest to check by using the piggyback technique or by using a Sys-Check-II device - bought from user TF_HH. There are many forum topics that go into greater detail. just to set Beeblebrox straight, the European ingot power supplies are fine, its the USA ones that are moody. Quote Link to comment Share on other sites More sharing options...
Beeblebrox Posted October 26, 2021 Share Posted October 26, 2021 40 minutes ago, xrbrevin said: just to set Beeblebrox straight, the European ingot power supplies are fine, its the USA ones that are moody. @xrbrevin ah, I did not know that. Thanks. 1 Quote Link to comment Share on other sites More sharing options...
mimo Posted October 26, 2021 Share Posted October 26, 2021 I'm not knowledgeable enough to know the answer to this but I have only ever seen Mt ram in a 65xe. Is there any evidence of it being replaced at some point? Maybe it wasn't done very well? And if you need a double layer mylar I can highly recommend the ones made by dudie of this parish. Good luck with the fixin' looking forward to following progress Quote Link to comment Share on other sites More sharing options...
Beeblebrox Posted October 26, 2021 Share Posted October 26, 2021 (edited) ps just realised a typo in my post (#4) above which I now can't edit. I meant to type: The only PITA thing is all the RAM chips and others on the XE board are NOT socketed. Edited October 26, 2021 by Beeblebrox Quote Link to comment Share on other sites More sharing options...
bfollowell Posted October 26, 2021 Share Posted October 26, 2021 5 hours ago, mimo said: I'm not knowledgeable enough to know the answer to this but I have only ever seen Mt ram in a 65xe. Is there any evidence of it being replaced at some point? Maybe it wasn't done very well? And if you need a double layer mylar I can highly recommend the ones made by dudie of this parish. Good luck with the fixin' looking forward to following progress MT RAM is definitely used in a lot more machines than just a 65XE. I think it was used a lot in all XL/XE machines. I have at least one 800XL with MT RAM. Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted October 26, 2021 Share Posted October 26, 2021 if you end up with the wrong type of membrane, there are workarounds - one is to add an M3 washer behind each rubber plunger or the other is to insert a small grub screw into each plastic plunger. depending on type Quote Link to comment Share on other sites More sharing options...
Beeblebrox Posted October 26, 2021 Share Posted October 26, 2021 4 minutes ago, xrbrevin said: if you end up with the wrong type of membrane, there are workarounds - one is to add an M3 washer behind each rubber plunger or the other is to insert a small grub screw into each plastic plunger. depending on type @xrbrevin Funnily enough the 7mm OD m3 plastic washer trick is exactly what I did with my dual mylar/membrane and the single type keyboard. (Simius put me onto it). The only thing it does is make the key press feel stunted as the keys lose a couple of mm of down movement. Guess it's worth getting thinner washers next time round. It took around 20mins to install them and what really helped was a curved set of electrician's tweezers. Quote Link to comment Share on other sites More sharing options...
mimo Posted October 26, 2021 Share Posted October 26, 2021 29 minutes ago, bfollowell said: MT RAM is definitely used in a lot more machines than just a 65XE. I think it was used a lot in all XL/XE machines. I have at least one 800XL with MT RAM. I may have miss worded that. I have not seen sharp ram in an XE before, I have definitely seen Mt ram in a 800xl Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted October 26, 2021 Share Posted October 26, 2021 4 minutes ago, Beeblebrox said: It took around 20mins to install them nice, it takes patience for sure! and still superior to the original weak mylar ? Quote Link to comment Share on other sites More sharing options...
manterola Posted October 26, 2021 Share Posted October 26, 2021 What kind of 65XE do you have in your hands? If it is one with ECI, it is great since there are just 2 RAM chips to change, very easy, as you can just cut the feet of the chips and then desolder each pin separately. Also a good thing is that Syscheck can be used with those machines. Not only that, you can transform that machine in a 130xe easily if you can find an EMMU chip. Quote Link to comment Share on other sites More sharing options...
Beeblebrox Posted October 26, 2021 Share Posted October 26, 2021 17 minutes ago, xrbrevin said: nice, it takes patience for sure! and still superior to the original weak mylar ? True. The mylars Simius sold me are quality and less costly than the other XE ones I've seen. Quote Link to comment Share on other sites More sharing options...
Simon Carter Posted October 27, 2021 Author Share Posted October 27, 2021 Wow, So many answers, thanks guys. First things first: Definitely says Sharp! I have Sharp RAM in both my 65XEs. I was going to ask if its possible to convert a 65 into a 130 with extra RAM and an MMU but @manterola already seems to have answered that one. I had replaced the membrane in my first 65XE, and had made the error of choosing the wrong type, but fixed it with washers as @xrbrevin suggested, does seem to have made the keyboard less responsive though ?. I think I'll pick up a proper membrane when I have the funds. Re the ingot power supplies - I thought the UK ones were just as bad as the US ones? Apparently not, although I'm sure one killed my 800XL... Looking forward to getting some RAM and having a stab at fixing the XL and the XE. Slowly regrowing my childhood collection: And yes, the dressing gown is mine... Regards Si Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted October 27, 2021 Share Posted October 27, 2021 22 minutes ago, Simon Carter said: to convert a 65 into a 130 aside from the extra RAM chips you will need a 74LS95 for U35 and a programmed GAL16V8D for U34 Quote Link to comment Share on other sites More sharing options...
manterola Posted October 27, 2021 Share Posted October 27, 2021 (edited) 3 hours ago, xrbrevin said: aside from the extra RAM chips you will need a 74LS95 for U35 and a programmed GAL16V8D for U34 Or the emmu CO25953, very hard to find nowadays. However, I have never done that ram expansion myself in that motherboard version. I did it in a motherboard that uses 4464 RAM chips, so I needed to add the emmu and 2 4464 chips, nothing else. Edited October 27, 2021 by manterola Quote Link to comment Share on other sites More sharing options...
Simon Carter Posted October 27, 2021 Author Share Posted October 27, 2021 18 hours ago, manterola said: What kind of 65XE do you have in your hands? If it is one with ECI, it is great since there are just 2 RAM chips to change, very easy, as you can just cut the feet of the chips and then desolder each pin separately. Also a good thing is that Syscheck can be used with those machines. Not only that, you can transform that machine in a 130xe easily if you can find an EMMU chip. This was something else I meant to ask - both my XEs have the ECI bus, but also have 8x8k RAM. Only have two to check/change would make things a lot easier... Quote Link to comment Share on other sites More sharing options...
mimo Posted October 27, 2021 Share Posted October 27, 2021 (edited) 56 minutes ago, Simon Carter said: This was something else I meant to ask - both my XEs have the ECI bus, but also have 8x8k RAM. Only have two to check/change would make things a lot easier... Yep most European 65xe's used the 130xe boards with only half the ram populated , but with the eci port Edited October 27, 2021 by mimo Fixed it Quote Link to comment Share on other sites More sharing options...
+ZuluGula Posted October 27, 2021 Share Posted October 27, 2021 My European 65XE bought around 1987 didn't have ECI. 1 Quote Link to comment Share on other sites More sharing options...
Beeblebrox Posted October 27, 2021 Share Posted October 27, 2021 @Simon Carter I wonder if you could post a photo of the entire 65XE's PCB? Quote Link to comment Share on other sites More sharing options...
Simon Carter Posted October 27, 2021 Author Share Posted October 27, 2021 1 hour ago, Beeblebrox said: @Simon Carter I wonder if you could post a photo of the entire 65XE's PCB? Here you go... If you need more detail, just shout, wont be til tomorrow though 1 Quote Link to comment Share on other sites More sharing options...
Simon Carter Posted November 3, 2021 Author Share Posted November 3, 2021 Well, I've just picked up some RAM chips and tried piggybacking but no change, I did notice that, at some point, a previous owner has socketed the Freddie chip, I wondered whether this had failed previously. Might be an avenue to explore... Quote Link to comment Share on other sites More sharing options...
Sugarland Posted November 4, 2021 Share Posted November 4, 2021 Do any of the RAM chips get very hot? That's also a sign of RAM failure. Quote Link to comment Share on other sites More sharing options...
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