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Messages - John Fante

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Great to hear! Thank you for the feed back/review :)

@gflorez: Thank you for your - as allways - huge help :) I will start soldering .... :smt068

Well! This is certainly not my sommer when it comes to EP :( . First I managed to mess my EP128 when I tried to fix a video problem. Now I can not get my "new" Egyptian EP64 to start. More on that later.

First: Are there anybody - besides ZoZo who is a bit out of the loop at the moment - who does EP repair work? I can solder a bit but I do not have the equipment or knowledge to fix major issues. I will ofcourse pay for the time, postage etc. I would highly appreciate it if anybody are willing to give it a go!

Secondly. The Egyptian EP64 problem (the 128 problem is described in the thread linked to above). The machine I recieved is in VERY good condition. Clean an clearly not used. The red led lights when I power it on and you can hear very low static in the speaker so there is some kind of activity. However there is no video output and there is no click when I press the keys so it is not booting.

There is also some kind of signal comming out of the RGB port. My OSSC registers this but no picture. Normally the frequency should be like this.

My first instinct would be the two voltage regulators (7805) to see if the machine is getting enough power. They are however fine. The next would be to recap the machine. Capacitors does not age well.

It would be a very big challenge for me to do a recap. Does anybody here has some advice on doing it and does anybody have a complete list of the replacement capacitors I need?  

Or is there any other suggestions/advice?

I have done a first check of the motherboard and it looks fine. You can see it here and a closeup of the power section here.

Sorry for taking your time with my issues. This has really been an EP sommer from hell. Instead of playing with my Symbiface3 as planned I have been bogged down with technical issues.

I hope someone will be able to help so I can get at least one of the machines up and running.

Thank you in advance!

And about leaving your "old EP" without the internal ROM, you say that you plan to inject it with the SF3.

Ok, remember to put on the INI file the line

Code: [Select]
and the line

Code: [Select]
ROM[#00]  =SD:EXOS2.4.ROM
Remember that your old EP will only start with the SF3 connected.

Thank you :)

So an INI file like this should do the trick for an EP64 with the old rom removed?

Code: [Select]
*      SF3 INI FILE                                        
*Wifi settings.  Up to 5 wifi providers can be put here,  
*                the first has the gratest priority


*TMTnet settings




* The Roms can be in any place of the SD or on a web page

ROM[#00]  =SD:ROMS/exos24uk.ROM
*ROM[#64]  =SD:ROMS/epd19uk.rom
*ROM[#66]  =SD:forth.rom

*ROM[#67] =HTTP:www.tmtlogic.com/cyrus.rom

* Audio settings SYMAMP for symbos audio

Thank you for all the great advise :)

Just one thing. On my present machine the ROM is not wired to the expansion port but to the U6 chip. See here.

The wire to the expansion port is wired like this.

Is this an alternative way of doing it?

In the english monarchy you use the expression "An heir and a spare" when you have an extra son if the heir is killed in battle.

I now have an spare. Or to be more precise an Egyptian EP spare :)

I have so far not found a solution to my frequency problem. Hopefully it will show up soon but until then I will use the Ep64 I have just bought in Egypt. If it works that is ... I just could not wait and hopefully the "new" machine does not have the same artifact problem that started all this.

I am considering moving my Exos 2.4 rom from my present nonfunctioning machine to the new one. I understand that I also need to solder a ekstra wire besides moving the ROM. Can anybody direct my to a more precise description?

But first I will use my Symbiface to inject the ROM (and remove the present exos2.0). Does anybody have a link to the latest EXOS2.4 ROM with IS basic etc.?

Thank you in advance!

I have gotten a (small) bit further :)

When I alter the settings on C43 and L2 I get changes in the output signal that the OSSC recieves. It therefore looks like they are working - at least a bit - but are not configures correctly.

Does anybody know how to configure C43 and L2 and what the correct settings are?

Thank you in advance!

We also shoot sparrows with cannons here in Denmark :)  .... A very fitting expressions since I right now feel like shooting something :evil:

Back to the problem!

@gflorex: You are of course right that it should have been EXOS not EXDOS. Typing error that has been corrected.

It is - unfortunately - not the cable. I am using a new - and very good - cable that judge supplied and have tried with a couple of others from retrocables. Same result.

The powersupply is also fine and I have also tested the 7805 voltage regulators to be sure that they where giving the correct 5v voltage. They give 4,98 and 4,99 so they are fine and are not causing the artefact.

I therefore turned to trying to adjusting the Nick clock - as advised by Zozo - with C43 and L2. C43 and L2 - as far as I know - starts/adjust the crystal that controls the Nick clock.

I had problems finding L2 so by mistake I at first started messing a bit around with R202. I think I have set that back to the correct value so that it outputs 2,83 voltage. And since R202 only controls the voltage to the RF modulator that should not be the cause here.

At first I adjusted C43 and R202 when the machine was on to see the effect on the picture. I did not see any effect but after doing that I turned the machine off and I lost picture.

Or to be more correct I can not see the picture. I am using an OSSC and it looks like the machine is outputting some kind of signal that at least the OSSC can not use. See examples here and here.

The possibilities are - as I see them - as follows:

1) I have messed to much around with R202 and fried something along the way. Not that likely since it runs to the RF output.

2) C43 (and maybe L2) is either badly out of position so that it/they does not start the crystal/Nick correctly or they are out of order.

3) I have shortcircuted something along the way - I was also planning to remove the internal speaker and therefore removed the glue under it so that it is now moving around freely with the risk of a shortcircut.

At the moment I have some limitations in error finding:

I do not own an oscilloscope. And buying one is almost as expensive as buying a new Egyptian EP :)

My voltagemeter broke last night - I will get a new but it will take a day or two. But for now I can not messaure anything.

I know it is a rather big thing to just buy a new machine but I must admit that the screen artifacts I have really has taken the joy out of using the EP :(

So either I need to be able to fix the machine or someone else - any volunteers? - has to give it a go. I will ofcourse pay for the trouble. Or else it is the Egyptian way. And as glorez states: It is always nice to have an extra EP.

I have been struggeling with a strange display artefact and while trying to fix it I managed to mess up the RGB signal.

In short I messed to much around with C43, R202 (yes I know it was wrong) and a little with L2 and now I can not get Nick to produce a picture and I do not have an oscilloscope etc. to adjust the settings to things going.

Any suggestions to fix this?

I am - as a last resort - considering bying a Egyptian EP64 to use as backup. I am using a Symbiface 3 for RAM so that should not be a problem.

My question is. I have a Exos 2.4 ROM in my present machine? Can I just swap that out with the ROM on the EP64? Or is it better to use Symbiface 3 for that?

Is there any other modifications for a EP64 that I need to do?

@Getafix: Could you give us a report on how it goes buying the nem membrame?

Will soon be needing a new one my self :)

For Sale / EP128 on sale on Facebook in Athens
« on: 2020.July.23. 09:53:37 »
I am on holiday in Greece. Stumbled over this EP128 on Facebook-marketplace in Athens.

Cheap an nice looking :)

Hardware / Re: Questions about SymbiFace3
« on: 2020.July.14. 19:31:43 »
I tried with EPRAM[#05-#07]  but then I got an 64K ram error and no SD card reader working/showing up.

Wanted / Re: 1MB RAM expansion with built in Exos 2.4
« on: 2020.July.14. 17:13:09 »
Removing the expansion solved the problem.

If anyone is interested in trying to fix the expansion please let me know :)

Hardware / Re: Questions about SymbiFace3
« on: 2020.July.14. 16:59:01 »
@gflorez: Once again thank you for all your hard work for the platform :)

I had to remove my faulty RAM expansion and now everything seems to run stable again. But that means that I am down to 64KB without the Sf3 .... :smt073

I have therefore inserted these RAM-settings in the ini file

Code: [Select]

I have a SD card reader so I am not injecting

Code: [Select]

Is that the optimal setting for my special system?

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