Re: [neonixie-l] Re: unpoison a IN-1

[Benoit Tourret]

Thanks Terry.

this also will help me a lot.
My electronic courses are too far to be clear in my mind...

When I read gregebert's thread, I wanted to write the complete equation to 
calculate the resistor for a wanted current. but the result was the 
opposite of the reality... 
so I decided to use a potentiometer and a galva...
but you gave me the result !!!
Le samedi 22 avril 2023 à 22:13:14 UTC+2, Mac Doktor a écrit :

> Reading this thread has begun to make my eyes glaze over. I find the 
> following diagram to be helpful for understanding some of what's going on. 
> Perhaps it will add some clarity to the discussion. This in from Marcin 
> Saj's github and specifically concerns his PRO Nixie Tester:
>
> [image: pro-nixie-tester-how-to-use-02.jpg]
> It took a while for me to completely understand how all of this works and 
> this diagram was a huge help. I doubt that I would have worked it clearly 
> otherwise. For the record I haven't gotten around to reading the JB Dance 
> book—yet.
>
> Full info here:
>
> https://github.com/marcinsaj/Universal-PRO-Nixie-Tester-and-Healer
>
>
> Right now I'm using the PRO Nixie Tester with three DMMs but I've 
> purchased some DPMs for a compact, dedicated meter bridge. Someday I'll get 
> around to making a panel and wiring them up. And rigging up isolated power 
> supplies for them.
>
>
> On Apr 22, 2023, at 1:50 PM, Moses  wrote:
>
> That yh11068a module is rated for 40 watts! That is like 10 times what you 
> would need for most nixie clocks! Be careful at higher voltages, a 200mA 
> capable supply at a few hundred volts will hurt you good.
>
>
> Zaparooney.   x_x
>
>
> Terry Bowman, KA4HJH
> "The Mac Doctor"
>
> https://www.astarcloseup.com
>
> "If only you could see what I've seen with your eyes."—Roy Batty, *Blade 
> Runner*
>
>

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[neonixie-l] Re: unpoison a IN-1

[Benoit Tourret]

Thanks Moses.

I put a drawing to explain the "resistor and the Ammeter" cause one is 
serial and the other in //

I found the specs of a 
rheostat: https://docs.rs-online.com/736e/0900766b8142087d.pdf but I don't 
see the max voltage.
Le samedi 22 avril 2023 à 19:50:36 UTC+2, Moses a écrit :

> Benoit,
>
> I'll try and clarify what I can for you.
>
> "the voltmeter should be in place of the resistance and vice versa"... I 
> think you mean ammeter here? If so, the ammeter is in series, so it 
> shouldn't matter where it is really. If you really did mean voltmeter.. it 
> depends on if you want to read the power supply voltage or the voltage drop 
> on your nixie tube.
>
> For the power of your resistor: Once the nixie tube lights.. the 
> sustaining voltage is going to be around 140v or so on the nixie tube. 
> Leaving about 40v drop on your resistor. Power dissipation on your resistor 
> will then be.. P=VI, P=40*0.0025ma, P=0.1watts. I normal 1/4 watt resistor 
> should be fine. Same calculation applies if you want to put a rheostat on 
> your tube, a smaller one should be fine. No need for 200kg one lol
> Do remember, one dropping resistor per nixie tube. Pay attention to the 
> voltage rating on the resistor too, most small ones are a maximum of 200v 
> or 250v, for the rheostat see if you can find the datasheet for this max 
> voltage. Yes, the sustaining voltage is a lot lower on the resistor, but I 
> would try and use one that is rated for your supply voltage.
>
> If you are using a rheostat for adjusting the tube current, put a resistor 
> in series as well to set your lower value. This is so you don't drive the 
> tube with 0 ohm resistance when you turn it all the way down. A 20k or so 
> should be ok.
>
> That yh11068a module is rated for 40 watts! That is like 10 times what you 
> would need for most nixie clocks! Be careful at higher voltages, a 200mA 
> capable supply at a few hundred volts will hurt you good.
>
> Regards,
> -Moses
>
> On Saturday, April 22, 2023 at 5:30:08 AM UTC-7 Benoit Tourret wrote:
>
>> In order to be able to talk about the same thing, I have a few questions 
>> regarding my DC power supply.
>> I have in order: a 0-30V / 0-10A adjustable DC power supply, a  NCH6100HV 
>> (12-24V 
>> to 85-235V HV) module, a 0-300V DC voltmeter, a 0-30mA ammeter and a 32.4 
>> kΩ  limiting resistor  mounted on the wire that goes to the tube.
>> in my opinion, the voltmeter should be in place of the resistance and 
>> vice versa. so far, am I okay?
>>
>> If I replace the adjustable resistor of the HT module with a 
>> potentiometer on the front, I can modify the voltage.
>> My current limiting resistor (a USSR model salvaged from a IN-12 nixie 
>> board) measures 10mm x 4mm. I have no idea of its power or the power 
>> needed, as I want to change the intensity, I have to replace my resistor 
>> with a second potentiometer.
>> I thought of a potentiometer of 50 or 100k. But what power... a small 
>> Chinese knob or a large rehostat of 200 kilograms?
>> I don't want to power much more than 5 or 6 tubes.
>> Until now my DC power supply never showed anything other than 0.00 A
>>
>> Am I completely off the mark or is it doable?
>> I also have a DC-DC yh11068a module (
>> https://dalmura.com.au/static/YH11068A.pdf
>>
>> Here in France, ebay is not used by companies to resell their used 
>> equipment. Removing an item from an inventory requires tons of paperwork. 
>> So, finding a power supply for an EDM machine is rather complicated.
>>
>> Le vendredi 21 avril 2023 à 23:41:38 UTC+2, Moses a écrit :
>>
>>> I've always just "unpoisoned" tubes with slightly higher current then 
>>> normal, not higher voltage. A couple of hours to a few days usually fixes 
>>> them for me. I don't think a 150-200% overdrive on the current will hurt it 
>>> too much for a short duration. I've seen some tubes unpoisoned right in 
>>> front of my eyes after just a few minutes at around double the current.
>>>
>>> I've used brand new tubes where some digits didn't light fully.. usually 
>>> after a few days of normal usage, at normal current levels, they came back. 
>>> I've always viewed this as normal. I figure they have been sitting unlit 
>>> for decades, it may take a little while to get everything lit up.
>>>
>>> Regards,
>>> -Moses
>>>
>>> On Friday, April 21, 2023 at 1:19:55 PM UTC-7 Benoit Tourret wrote:
>>>
 I don't know how to rise the intensity...
 I wish I had a laboratory DC power supply, but mine stops at 30V.
 so I put a  NCH6300HV to raise the voltage. If I can adjust the 
 voltage, I cannot adjust anything else. 
 however I added a voltmeter and ammeter to check what I'm sending to 
 the tube. Do you know if there is an adjustable power supply that can be 
 used for our beloved tubes?
 So, I regulate the voltage and I check that I do not exceed the desired 
 values.

 should I change the 32K resistor between the PS and the tube? could a 
 

Re: [neonixie-l] Re: unpoison a IN-1

[Mac Doktor]

Reading this thread has begun to make my eyes glaze over. I find the following 
diagram to be helpful for understanding some of what's going on. Perhaps it 
will add some clarity to the discussion. This in from Marcin Saj's github and 
specifically concerns his PRO Nixie Tester:


It took a while for me to completely understand how all of this works and this 
diagram was a huge help. I doubt that I would have worked it clearly otherwise. 
For the record I haven't gotten around to reading the JB Dance book—yet.

Full info here:

https://github.com/marcinsaj/Universal-PRO-Nixie-Tester-and-Healer 



Right now I'm using the PRO Nixie Tester with three DMMs but I've purchased 
some DPMs for a compact, dedicated meter bridge. Someday I'll get around to 
making a panel and wiring them up. And rigging up isolated power supplies for 
them.


> On Apr 22, 2023, at 1:50 PM, Moses  wrote:
> 
> That yh11068a module is rated for 40 watts! That is like 10 times what you 
> would need for most nixie clocks! Be careful at higher voltages, a 200mA 
> capable supply at a few hundred volts will hurt you good.

Zaparooney.   x_x


Terry Bowman, KA4HJH
"The Mac Doctor"

https://www.astarcloseup.com

"If only you could see what I've seen with your eyes."—Roy Batty, Blade Runner

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[neonixie-l] Re: unpoison a IN-1

[Moses]

Benoit,

I'll try and clarify what I can for you.

"the voltmeter should be in place of the resistance and vice versa"... I 
think you mean ammeter here? If so, the ammeter is in series, so it 
shouldn't matter where it is really. If you really did mean voltmeter.. it 
depends on if you want to read the power supply voltage or the voltage drop 
on your nixie tube.

For the power of your resistor: Once the nixie tube lights.. the sustaining 
voltage is going to be around 140v or so on the nixie tube. Leaving about 
40v drop on your resistor. Power dissipation on your resistor will then 
be.. P=VI, P=40*0.0025ma, P=0.1watts. I normal 1/4 watt resistor should be 
fine. Same calculation applies if you want to put a rheostat on your tube, 
a smaller one should be fine. No need for 200kg one lol
Do remember, one dropping resistor per nixie tube. Pay attention to the 
voltage rating on the resistor too, most small ones are a maximum of 200v 
or 250v, for the rheostat see if you can find the datasheet for this max 
voltage. Yes, the sustaining voltage is a lot lower on the resistor, but I 
would try and use one that is rated for your supply voltage.

If you are using a rheostat for adjusting the tube current, put a resistor 
in series as well to set your lower value. This is so you don't drive the 
tube with 0 ohm resistance when you turn it all the way down. A 20k or so 
should be ok.

That yh11068a module is rated for 40 watts! That is like 10 times what you 
would need for most nixie clocks! Be careful at higher voltages, a 200mA 
capable supply at a few hundred volts will hurt you good.

Regards,
-Moses

On Saturday, April 22, 2023 at 5:30:08 AM UTC-7 Benoit Tourret wrote:

> In order to be able to talk about the same thing, I have a few questions 
> regarding my DC power supply.
> I have in order: a 0-30V / 0-10A adjustable DC power supply, a  NCH6100HV 
> (12-24V 
> to 85-235V HV) module, a 0-300V DC voltmeter, a 0-30mA ammeter and a 32.4 
> kΩ  limiting resistor  mounted on the wire that goes to the tube.
> in my opinion, the voltmeter should be in place of the resistance and vice 
> versa. so far, am I okay?
>
> If I replace the adjustable resistor of the HT module with a potentiometer 
> on the front, I can modify the voltage.
> My current limiting resistor (a USSR model salvaged from a IN-12 nixie 
> board) measures 10mm x 4mm. I have no idea of its power or the power 
> needed, as I want to change the intensity, I have to replace my resistor 
> with a second potentiometer.
> I thought of a potentiometer of 50 or 100k. But what power... a small 
> Chinese knob or a large rehostat of 200 kilograms?
> I don't want to power much more than 5 or 6 tubes.
> Until now my DC power supply never showed anything other than 0.00 A
>
> Am I completely off the mark or is it doable?
> I also have a DC-DC yh11068a module (
> https://dalmura.com.au/static/YH11068A.pdf
>
> Here in France, ebay is not used by companies to resell their used 
> equipment. Removing an item from an inventory requires tons of paperwork. 
> So, finding a power supply for an EDM machine is rather complicated.
>
> Le vendredi 21 avril 2023 à 23:41:38 UTC+2, Moses a écrit :
>
>> I've always just "unpoisoned" tubes with slightly higher current then 
>> normal, not higher voltage. A couple of hours to a few days usually fixes 
>> them for me. I don't think a 150-200% overdrive on the current will hurt it 
>> too much for a short duration. I've seen some tubes unpoisoned right in 
>> front of my eyes after just a few minutes at around double the current.
>>
>> I've used brand new tubes where some digits didn't light fully.. usually 
>> after a few days of normal usage, at normal current levels, they came back. 
>> I've always viewed this as normal. I figure they have been sitting unlit 
>> for decades, it may take a little while to get everything lit up.
>>
>> Regards,
>> -Moses
>>
>> On Friday, April 21, 2023 at 1:19:55 PM UTC-7 Benoit Tourret wrote:
>>
>>> I don't know how to rise the intensity...
>>> I wish I had a laboratory DC power supply, but mine stops at 30V.
>>> so I put a  NCH6300HV to raise the voltage. If I can adjust the voltage, 
>>> I cannot adjust anything else. 
>>> however I added a voltmeter and ammeter to check what I'm sending to the 
>>> tube. Do you know if there is an adjustable power supply that can be used 
>>> for our beloved tubes?
>>> So, I regulate the voltage and I check that I do not exceed the desired 
>>> values.
>>>
>>> should I change the 32K resistor between the PS and the tube? could a 
>>> potentiometer be used?
>>>
>>> So I did see an improvement. but some need to be "heated". I of course 
>>> doesn't speak of temperature, but they need 10 to 20 seconds to get their 
>>> full glow, a bit like a neon tube with an old starter.
>>> They are 52 years old now and never been used.
>>>
>>> Le vendredi 21 avril 2023 à 16:20:59 UTC+2, gregebert a écrit :
>>>
 The IN-1 datasheet says 2.5mA typical operating current, 

[neonixie-l] Re: Help with 12" monochrome CRT circuit TDA1175/TDA1180

[gregebert]

I found this online (service manual for Ball Brothers video monitor). At 
the end of the document is a schematic, and you can see the pinout numbers 
(for the 10-pin card-edge connector) called-out on the schematic. For 
example, pins 1 and 10 are GND, 2,3, and 4 are for the external brightness 
control.

I used to test/repair terminals, printers, and small-business computers as 
a summer job, and encountered several video monitors from different 
manufacturers with this same pinout.

http://www.bitsavers.org/pdf/ballBrothers/5-017-1017B_Ball_TTL_Series_Service_Manual_Oct76.pdf

On Saturday, April 22, 2023 at 8:24:45 AM UTC-7 gregebert wrote:

> There was a standard 10-pin interface on video monitors back in the 
> 1980's, so you probably have that. I know the video, vert-sync, and horiz 
> sync were on the connector. Check pin 7; I recall that was for power and 
> usually had a fuse on the PCB board. You should be able to find a pinout on 
> the web.
>
> On Saturday, April 22, 2023 at 4:29:26 AM UTC-7 Paolo Cravero wrote:
>
>> Hello.
>> A friend gave me a 12" monochrome CRT with its circuits that was taken 
>> off an injection molding machine (most likely from the control console 
>> Sandretto Selec 90). As I haven't been able to find documentation I started 
>> reversing the circuit to understand the meaning of the 10 pins on the card 
>> edge connector.
>>
>> There is the PSU, the HV generator and two ICs TDA1175P (vertical 
>> deflection) and TDA1180P (horizontal processor). I write here in hope 
>> someone was into these circuits and can help me understand what I need to 
>> get it working.
>>
>> Checks completed so far: fuses don't blow, CRT filament glows, there's a 
>> 14 kHz whine (I cheated using an audio spectrum App), 12Vdc is present. 
>> Nothing on screen.
>>
>> The closest documentation I could find is this service manual 
>> http://oz1db.dk/hp/omnivision_man_lp06xx_rev0_0611.pdf, however I'm 
>> missing something.
>>
>> The 10-pin connector has 3x GND, 1x 12Vdc (output), the 3 contacts for 
>> (what I think is) the remote brightness control, 1x not connected. I am 
>> left with one contact going to a 2N which should be "video input" and 
>> another going to the TDA1180P horizontal processor. Where is the VSYNC 
>> input? Not needed?
>>
>> I've assembled an Arduino with the TVout library and got no reaction from 
>> the CRT both with just the [video signal] and [video signal + TVout sync 
>> output to the contact going to the TDA1180P]. The only difference between 
>> the two input configurations is that when I add the sync signal I hear a 
>> very low frequency buzz coming out of the screen circuits. I haven't been 
>> lucky enough to find a schematic diagram with both these ICs and just one 
>> sync input, and I've finished my guesses.
>>
>> I wonder if someone in this great community has experience with this 
>> circuit configuration and can suggest what kind of signals it is expecting. 
>> Also, should it show something with no input signal, or at least some 
>> noise? I know the dangers of EHT and I would try all low-voltage checks 
>> first.
>>
>> Thank you,
>> Paolo
>>
>>

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[neonixie-l] Re: Help with 12" monochrome CRT circuit TDA1175/TDA1180

[gregebert]

There was a standard 10-pin interface on video monitors back in the 1980's, 
so you probably have that. I know the video, vert-sync, and horiz sync were 
on the connector. Check pin 7; I recall that was for power and usually had 
a fuse on the PCB board. You should be able to find a pinout on the web.

On Saturday, April 22, 2023 at 4:29:26 AM UTC-7 Paolo Cravero wrote:

> Hello.
> A friend gave me a 12" monochrome CRT with its circuits that was taken off 
> an injection molding machine (most likely from the control console 
> Sandretto Selec 90). As I haven't been able to find documentation I started 
> reversing the circuit to understand the meaning of the 10 pins on the card 
> edge connector.
>
> There is the PSU, the HV generator and two ICs TDA1175P (vertical 
> deflection) and TDA1180P (horizontal processor). I write here in hope 
> someone was into these circuits and can help me understand what I need to 
> get it working.
>
> Checks completed so far: fuses don't blow, CRT filament glows, there's a 
> 14 kHz whine (I cheated using an audio spectrum App), 12Vdc is present. 
> Nothing on screen.
>
> The closest documentation I could find is this service manual 
> http://oz1db.dk/hp/omnivision_man_lp06xx_rev0_0611.pdf, however I'm 
> missing something.
>
> The 10-pin connector has 3x GND, 1x 12Vdc (output), the 3 contacts for 
> (what I think is) the remote brightness control, 1x not connected. I am 
> left with one contact going to a 2N which should be "video input" and 
> another going to the TDA1180P horizontal processor. Where is the VSYNC 
> input? Not needed?
>
> I've assembled an Arduino with the TVout library and got no reaction from 
> the CRT both with just the [video signal] and [video signal + TVout sync 
> output to the contact going to the TDA1180P]. The only difference between 
> the two input configurations is that when I add the sync signal I hear a 
> very low frequency buzz coming out of the screen circuits. I haven't been 
> lucky enough to find a schematic diagram with both these ICs and just one 
> sync input, and I've finished my guesses.
>
> I wonder if someone in this great community has experience with this 
> circuit configuration and can suggest what kind of signals it is expecting. 
> Also, should it show something with no input signal, or at least some 
> noise? I know the dangers of EHT and I would try all low-voltage checks 
> first.
>
> Thank you,
> Paolo
>
>

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[neonixie-l] Re: unpoison a IN-1

[Benoit Tourret]

In order to be able to talk about the same thing, I have a few questions 
regarding my DC power supply.
I have in order: a 0-30V / 0-10A adjustable DC power supply, a  NCH6100HV 
(12-24V 
to 85-235V HV) module, a 0-300V DC voltmeter, a 0-30mA ammeter and a 32.4 
kΩ  limiting resistor  mounted on the wire that goes to the tube.
in my opinion, the voltmeter should be in place of the resistance and vice 
versa. so far, am I okay?

If I replace the adjustable resistor of the HT module with a potentiometer 
on the front, I can modify the voltage.
My current limiting resistor (a USSR model salvaged from a IN-12 nixie 
board) measures 10mm x 4mm. I have no idea of its power or the power 
needed, as I want to change the intensity, I have to replace my resistor 
with a second potentiometer.
I thought of a potentiometer of 50 or 100k. But what power... a small 
Chinese knob or a large rehostat of 200 kilograms?
I don't want to power much more than 5 or 6 tubes.
Until now my DC power supply never showed anything other than 0.00 A

Am I completely off the mark or is it doable?
I also have a DC-DC yh11068a module 
(https://dalmura.com.au/static/YH11068A.pdf

Here in France, ebay is not used by companies to resell their used 
equipment. Removing an item from an inventory requires tons of paperwork. 
So, finding a power supply for an EDM machine is rather complicated.

Le vendredi 21 avril 2023 à 23:41:38 UTC+2, Moses a écrit :

> I've always just "unpoisoned" tubes with slightly higher current then 
> normal, not higher voltage. A couple of hours to a few days usually fixes 
> them for me. I don't think a 150-200% overdrive on the current will hurt it 
> too much for a short duration. I've seen some tubes unpoisoned right in 
> front of my eyes after just a few minutes at around double the current.
>
> I've used brand new tubes where some digits didn't light fully.. usually 
> after a few days of normal usage, at normal current levels, they came back. 
> I've always viewed this as normal. I figure they have been sitting unlit 
> for decades, it may take a little while to get everything lit up.
>
> Regards,
> -Moses
>
> On Friday, April 21, 2023 at 1:19:55 PM UTC-7 Benoit Tourret wrote:
>
>> I don't know how to rise the intensity...
>> I wish I had a laboratory DC power supply, but mine stops at 30V.
>> so I put a  NCH6300HV to raise the voltage. If I can adjust the voltage, 
>> I cannot adjust anything else. 
>> however I added a voltmeter and ammeter to check what I'm sending to the 
>> tube. Do you know if there is an adjustable power supply that can be used 
>> for our beloved tubes?
>> So, I regulate the voltage and I check that I do not exceed the desired 
>> values.
>>
>> should I change the 32K resistor between the PS and the tube? could a 
>> potentiometer be used?
>>
>> So I did see an improvement. but some need to be "heated". I of course 
>> doesn't speak of temperature, but they need 10 to 20 seconds to get their 
>> full glow, a bit like a neon tube with an old starter.
>> They are 52 years old now and never been used.
>>
>> Le vendredi 21 avril 2023 à 16:20:59 UTC+2, gregebert a écrit :
>>
>>> The IN-1 datasheet says 2.5mA typical operating current, so you should 
>>> try cleaning the other 3 tubes at just under 3mA. The other 7 tubes might 
>>> clean-up on their own at normal current if the usage is balanced.
>>>
>>> So did you see some improvement ? 
>>>
>>> On Friday, April 21, 2023 at 12:14:05 AM UTC-7 Benoit Tourret wrote:
>>>
 I ran each tube with 180V 2mA / two hours, turning each plate for 2 
 minutes.

 on 10 tubes:

 7 are OK
 3 are not perfect.

 I will wait to be able to lit them all together.


 Le jeudi 20 avril 2023 à 01:27:40 UTC+2, gregebert a écrit :

> I couldn't resist asking google Bard this question: Are IN-1 nixie 
> tubes reliable ?
> Well, here's the answer. Feel free to laugh.love the part about 
> the filaments. Geez, maybe that's why I had so much trouble with mine ?
>
> IN-1 nixie tubes are generally reliable, but they can fail over time. 
> The most common failure mode is a leak in the vacuum tube. This can 
> happen 
> due to a number of factors, including manufacturing defects, physical 
> damage, or exposure to extreme temperatures.
>
> If a leak develops, the tube will slowly fill with air and the 
> filaments will eventually burn out. This can happen over a period of 
> months 
> or even years. To prevent leaks, it is important to store IN-1 nixie 
> tubes 
> in a cool, dry place and to avoid dropping or banging them.
>
> Another potential failure mode is a failure of the heater filament. 
> This can happen due to a number of factors, including overheating, 
> overvoltage, or physical damage. If the heater filament fails, the tube 
> will not light up.
>
> To prevent heater filament failures, it is important to use a 

[neonixie-l] Help with 12" monochrome CRT circuit TDA1175/TDA1180

[Paolo Cravero]

Hello.
A friend gave me a 12" monochrome CRT with its circuits that was taken off
an injection molding machine (most likely from the control console
Sandretto Selec 90). As I haven't been able to find documentation I started
reversing the circuit to understand the meaning of the 10 pins on the card
edge connector.

There is the PSU, the HV generator and two ICs TDA1175P (vertical
deflection) and TDA1180P (horizontal processor). I write here in hope
someone was into these circuits and can help me understand what I need to
get it working.

Checks completed so far: fuses don't blow, CRT filament glows, there's a 14
kHz whine (I cheated using an audio spectrum App), 12Vdc is present.
Nothing on screen.

The closest documentation I could find is this service manual
http://oz1db.dk/hp/omnivision_man_lp06xx_rev0_0611.pdf, however I'm missing
something.

The 10-pin connector has 3x GND, 1x 12Vdc (output), the 3 contacts for
(what I think is) the remote brightness control, 1x not connected. I am
left with one contact going to a 2N which should be "video input" and
another going to the TDA1180P horizontal processor. Where is the VSYNC
input? Not needed?

I've assembled an Arduino with the TVout library and got no reaction from
the CRT both with just the [video signal] and [video signal + TVout sync
output to the contact going to the TDA1180P]. The only difference between
the two input configurations is that when I add the sync signal I hear a
very low frequency buzz coming out of the screen circuits. I haven't been
lucky enough to find a schematic diagram with both these ICs and just one
sync input, and I've finished my guesses.

I wonder if someone in this great community has experience with this
circuit configuration and can suggest what kind of signals it is expecting.
Also, should it show something with no input signal, or at least some
noise? I know the dangers of EHT and I would try all low-voltage checks
first.

Thank you,
Paolo

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