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Restoring an Olivetti ETV260 that doesn't start up

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manumuna

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Joined
Jan 22, 2026
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Hi guys! I hope I'm doing everything properly.
I recently acquired an Olivetti ETV260 whit its own monitor. I'm quite used to restore old stuff but this machine is really giving me quite an hard time.
Firstly, I got it from a person who told me he tried to turn it on after something like 30 years of being in a storage room. I had a bit of a goose bump but when I opened it I found that nothing has blown. This person also told me that it didn't do anything: not a beep or a floppy drive moving. Nothing at all, even the leds on the keyboard didn't turn on.
So, I started opening it (my God, how many screws...) and I was finally able to arrive at the motherboard. Lots of dust but nothing seemed burnt or damaged. I firstly disconnected the power supply and tested it. It works like a charm, all the voltages are perfect. Then I changed all the electrolytic capacitors (11 of them are 47uF 25V and one 22uF 25V) on the motherboard. I also checked the monitor which gets its power from the main board and except a few caps on the high voltage section a bit worn out, the other were ok (I even tried to turn it on with my desk power supply and it seem fine). So, at this point I felt it was the right time to try and turn everything on.
And now comes the nice part... Nothing at all seems to happen. When I press the power switch, the PSU fan turns on and also the filament in the monitor's tube turns on. The leds on the keyboard don't even blink. You only hear a very faint pop from the speaker on the motherboard just as the fan in the PSU start to run. After a couple of minutes like that, the only thing that change is that the ICs on the board get a bit warm, like they're working but the screen remains black, no beeps or blink/noise from the floppy drives either. I tried, just to see if anything changed, to put in a POST Card and the only thing it says it's "FF --" but only if the processor is mounted, otherwise it has "-- --". All the leds on the post card turn on: the reset led turns on only for a second at the startup and then it turns off, while the others stay on. I tried to connect a normal XT keyboard and the difference with the original one is that this has the leds that blink at the start up and the caps, num lock and scroll lock, works normally, lighting or turning off the leds when pressed. I also tried with the same test (with the same keyboard) removing the processor (an intel 8088) and the leds didn't show anything at all even pressing their corresponding keys. With the processor on again, they worked properly again. So I started to think that something is still alive on this board. I also tried to change the position of the only jumper near the monitor connector (marked as LSW if I'm not mistaking) but nothing at all changed. I have removed all the ICs on the sockets (like the processor) and cleaned the contacts with a cleaner: same no difference. Just thinking that it could be something related with the PSU that I may not have seen testing it, so I hooked my desk supplies and tried with them with no difference again.
So, I'm here asking for advices on how I can proceed to troubleshoot this machine: without a scheme or a manual, I have no other specific ideas.
What can it be? How should I proceed? Which can be the best way to check what's can be faulty?
Reading online, even in this forum, I saw that lots of people have just changed the electrolytics and the machine started working fine.
 
Hello, welcome! I have five of them, one even untested yet, plus a very similar ETV 3000. But three of them are fully working.

It's already a wonder that you got opened it, specially the dark grey lower part of the chassis is quite tricky to remove. I hope that you have found the trick with the power switch, otherwise you damage the plastic fitter for the switch and then you are busted.

A port 80h POST card is of no help at all. The Olivetti PC bios doesn't use it. Instead (other Olivetti PC) use the parallel printer port. But I never tried that with the ETV 260 or M19, so I don't know if this would work.

When the standard XT keyboard blinks and reacts on the shift keys and so on this is a good sign, it means the board seems to be alive.

Does it access to the floppy? (Is it a dual floppy version or single floppy plus harddisk version?)

One of the most sensible parts of the ETV 260 is it's monitor, very often they need to be recapped, specially the high voltage capacitors next to the high voltage transformator for the tube. Cold solder points also can happen.

Another weak point of the machine is the plastics gearwheel between the tabulation modor and the print head ribbon driving belt.

In which country are you?
 
Yes, I was able to remove that part of the cover without breaking anything. I'm not 100% to have found the right trick, but I did it ! :)
What you say about the parallel port, do you mean that connecting a printer, if any errors happen, it should print something?
About the keyboard I have to say a little new thing about the original one. I was quite unlucky to test it last night and while I was trying to see if there was any difference after using another bit of contact cleaner, there was a blackout, so all the lights went off and I was lucky so see a glimpse from the leds on the original keyboard. So after the power came back, I tried to turn it on again in the dark this time, and so! Also the original keyboard has the leds working, very dimly but answering to the pressure of the correct keys. The only thing I'm wondering is that the led on the most right side was always on but changing a bit its intensity, especially when pressing the keys without any signs on the left side of the keyboard (where it should modernly be the Esc key).
The one that I have is the version with two floppy drives and no harddrive but they give no sign of life (I maybe should test them with another machine... I haven't thought of it).
The capacitors you mentioned are the exact two I changed, very close to the high voltage transformer and very close to the shield. I gave a check for cold solder but it seem that the rest of the control board is fine.
I tried to move with my hands the print head but it's really hard to move (I think because of the ratio change on the gears), anyway it doesn't move at all when I turn it on (like, I have few electronic typewriters and all of them when you turn them on have something like a home setting going lefthand side and aligning the char wheel).
Finally, I'm from Italy
 
manumuna said:
do you mean that connecting a printer, if any errors happen, it should print something?
Click to expand...
No. It does not use the handshake signals to tell the printer there is something. It only uses the data lines. It must be a special device which still might be available on eBay. (search for "Olivetti parallel port"), it has some LED numeric display.

You should also swap the other caps of the monitor but I can't promise you that this immeiatelly fix the issue. The big problem of M19 and ETV 260 is is that there is no easy solution to use an alternative monitor, it's timing is so unusual that no Multitsync can do that.

Be carefull with the printer, if it doesn't move by hand, it needs a good cleanup to get rid of old oil and grease. The printer will only begin to work if the system can load it's driver from disk.

Unfortunatelly I don't know any collector in Italy who has a ETV 260 as well to help you, for example testing the monitor on another machine. I know some Olivetti collector in Italy but they all mostly have "only" PCs, one who has masses of mechanical typewriters.
 
I took the machine to a little show near home so I had to put everything together again (tonight I will ope it again...)
Anyway, if the monitor isn't working, the machine will not start? Or better, if the main machine doesn't sense the original monitor, will it boot anyway or not? Not even giving any beep of error? I haven't find anything with the number as you suggested for the parallel port. Instead I managed with some leds and resistors to build something to see the signals (something like this https://forum.vcfed.org/index.php?t...-port-post-diagnostic-codes.55348/post-672858 but really more "on air"). After a second from switching the power button, the leds have a little change and stay steady as in the photo below. The second one from the right just turn on after a little while from the other two. From right to left, the leds are pin 2 to 9 of the parallel port. IMG_20260130_132108.jpg
 
I opened it again as said before and I tried to remove one a time all the chips mounted on a socket (I think I have already done it once, but I wasn't sure so I did it again). Nothing changed. The only difference I could note is that removing this memory (TMM24128AP, I suppose it's where the POST routine is written) the board really does nothing at all. Not the little buzz at the starting up, no leds on the serial port and no response from the led on the keyboard.
Am I hoping too much?
I also checked again all the voltages on the main ICs. They all seems good: 5V everywhere. I also checked the clock pin on the processor with the oscilloscope and I read 4.something MHz (I'm quite sure it's right) and both the address lines and the data lines have signals on them (almost like periodic square waves but not so periodic to let the scope trigger correctly... I hope it can be undestand what I'm meaning).
I hope in any ideasIMG_20260130_214255.jpg
 
The system would also boot without monitor. Good, that it (and M19) uses parallel port to display POST diagnostics. This POST on parallel port ends when the system is able to access video ram and continues there with the status display, like all other contemporary Olivett PC. We now can hope that it's the same codes as M24 Bios. You must decode them to their hexadecimal values.

For M24 I have:

1770064902267.png

If you want it more simple you may order such a device, it works nice with M24 and so it also should work with ETV 260 (and M19)

www.ebay.com

PCI Motherboard Diagnostic Tester Analyzer | eBay

Notebook Diagnostic Card will indicate exactly what is wrong with your notebook in just seconds. (4) Local pick up is not available. 1 English Manual.
www.ebay.com
www.ebay.com

USB Laptop Diagnostic Card Fault Test for Parallel Port with Four Digit Display | eBay

For wide ranging of motherboards, this diagnostic tool ensures comprehensive fault detection, making it indispensable asset for toolkit. Specifications: Item: Computer Fault Test Card.
www.ebay.com
 
So, from the photo I sent, if I'm reading it correctly, and also in this case the codes begin with a 4, the error code is 43. Is it correct? Meaning that the DMA controller is faulty? Or is it more probable the ram chips are faulty or something else related? Where do you think can be find a similar error code's list for, at least, the M19? Google is not helping me at all...
 
This is the only known list for early Olivetti PC. They might have not changed the meaning of the codes. I would start to search with the DMA controller. The big problem is, there is no circuit diagram for M19 / ETV 260 mainboard. Easiest might be to replace the DMA controller if you have one.
 
Ok, I'm going to order one from the internet in the next days. I will write here as soon as I have it. In the while, really really thanks!!!
 
The new DMA controller is on it's way. In the while I tried to fix the monitor with quite a good result I think. At the end I had to replace almost all the other electrolytics. They were completely out of tolerance or with crazy ESR, as you said 1ST1. I also had to change a transistor, a BC337, on the the section of the beam controller (contrast/luminance). After that, it came back to life. The only thing that puzzle me is that using a normal CGA card it does not sync properly. The image never stabilize vertically, while horizontally it sync perfectly with the minimum regulations on the horizontal hold and then when the circuitry warms up never sync properly again horizontally. Is it normal or do I have to search for any other faults?

IMG_20260207_163643.jpg
 

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VERY GOOD!

The ETV 260 and M19 PC are using different Video frequency as normal CGA. You can't use a standard CGA monitor on that and you can't use that monitor on another computer. Even M19 and ETV 260 might not be monitor compatible to each other as M19 which is the base mainboard for ETV 260 is only 4.77 MHz. The video part on both mainboards is a bit different. Additionally there is ETV 3000 which looks the same as ETV 260, but it again is different in the video part of the mainboard as it can support ETV 2700 monitor (with different timinng) with a composite video connector. It's even hard to get a multisync monitor to work with. And the signal is also not the same as on a standard CGA. That is digital RGB, but ETV 260 is more like MDA, videosignal plus intensity.

We intensively discussed the monitor things in the M19 threads.
choas75

Thread 'Olivetti M19'

Proud owner here of an M19 with extension box and colour monitor supporting 640x400. Unfortunately no dual speed kit.
Let me first say that my first encounter with the M19 was when my father got a two 5,25" floppy drive version and monochrome monitor, 256kB and 4.77Mhz.
It was soon upgraded with a 20MB harddrive and extended to 640kB for an outrageous amount of money (ripped off by a neighbor, payed by my father's work).
Anyway, the harddrive failed due to temperature problems and was soon replaced with a slower model and an MFM 90° turned ISA card.
Man, I had fun with this thing...
  • Like
Zare

Thread 'Paradise PVC2 questions on Olivetti M19'

Hello,

Usually documentation refers to graphics in this PC as Plantronics ColorPlus, but on the mainboard there's a PVC2 chip. System works in MDA, CGA and Plantronics modes. PVC2 also supports Hercules but as far as I remember it doesn't work.

What I'd like to know is whether PVC2 features can be turned on or off. I'd like to switch off CGA/Plantronics handling so I can try putting a VGA adapter in the machine's ISA slots.

Edit : Attached internet image of the relevant mainboard part

By the way, do you have a complete list of the capacitors you replaced? I have another two monitors to recap and I have lost my list of capacitors which I made when recapping the first one.
 
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I'm not 100% sure because I gave it a quick look a couple of minutes ago, but I will check more accurately along the week when I have a bit more time. Anyway, this is the list, while I will write again with the number on the PCB of each of them.
-4.7u 100V
-4.7u 100V
-470u 16V
-100u 100V
-2200u 16V
-100u 25V
-1000u 16V
-10u 50V
-22u 25V
-22u 25V
-22u 25V
-10u 160V
-220u 35V
-10u 160V
-47u 100V
-10u 50V
-22u 50V
-100u 50V
-22u 25V
I changed all of them except a couple of 22u. They were out of tolerance or with ESR so high to be scary XD
The thing that really amaze me is that, I know it was not so common to have a standard back in those days, even between Olivetti themself they didn't use a common standard for their machines... I really can't understand why.
And thank you so so much for your help and the links you attached!
 
Ah, and I was forgetting. I found quite useful this scheme of this Hantarex monitor: it's pretty similar to the one of the ETV260. Not exactly the same but a good guide/idea to troubleshoot, especially the part about the waves. For what I saw they are exactly the same.
 

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Interesting, thank you for this manual. It also might be usefull for M19. @Zare @Ghislain The main difference to the M19 ETV 260 should be different video signal (no composite video) and M19 monitor has internal power supply.
 
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Here is the complete list for sure.
On the main board:
C143-> 10u 160V
C144-> 47u 100V
C102-> 22u 25V
C101-> 22u 25V
C139-> 4,7u 100V
C123-> 100u 50V
C129-> 22u 25V
C105-> 10u 50V
C106-> 22u 25V
C133-> 4,7u 100V
C110-> 100u 25V
C111-> 470u 16V
C107-> 10u 50V
C103-> 100u 25V
C119-> 22u 25V
C121-> 2200u 16V
C126-> 1000u 16V
C109-> 2,2u 63V
Inside the EHT shield, close to the high voltage transformer:
C137-> 220u 35V
C135-> 10u 250V
On the final board connecting to the crt:
C204-> 22u 50V
C201-> 10u 160V
The voltages I wrote are the original one or slightly over the originals: I took note from the new one I used.

Yesterday also arrived the new DMA controller. I changed it and nothing happened different from the original. Reading on your links that the DMA controller tries to use the first 64K of ram to set itself up, I had the idea to give it a surely working 64k... So I removed and put the sockets on all the first column on DRAM (41256 type) and instead of those one, I put 8 new 4164 (spares I bought some time ago to fix a commodore 64. I checked the pinout and except for pin 1 - A8 for the 41256 and NC for 4164 - they looked compatible even from the timing chart, so I said, why not.... XD) and a "magic" happened! The error code changed and arrived to 45!!! I attach the photo and a video. But even, no bip or anything on screen... Same result using the new or the old controller.
Is this a good thing in your opinion? And what should I do in your experience now? Is it better to find a new set of 41256 for the first bank or for now just leave the 4164s there and go on troubleshooting the rest?
IMG_20260212_121747.jpg
IMG_20260212_104918~2.jpg
 

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Nope... it gets the power from the motherboard. A 12V DC up through pin 4 and 5 of the monitor connector. I saw that it requires around 1.1A at 12.3V. It doesn't have anything else to give him the power. On the monitor board, there is then a 7805 to create the +5V for the ICs that requires it (the are a few 74xx).
 
Nope... The highest voltage one I found was the 250V and 160V. No 400V at all on the boards. Only a few non-electrolytic capacitors are 400V but I can't remember which ones.
 
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