Hi @shahram-m, welcome to the KPN forum!  Apology accepted 

With your old ontvanger, you had your DVD-player connected to the ontvanger and not to the tv itself? That's not possible anymore nowadays. Do you have a second scart port on the tv itself? If so, you can connect both to the tv 

If your tv has only 1 scartport, you can switch from ontvanger to DVD-player and back when you want to watch a DVD or tv, or you can consider buying a scart switch so you can connect both devices to the tv at the same time!

Before I go further first these questions:

Does your tv only have one scart? And how many hdmi-ports has your tv?

Does your tv have an rca (also cinch) connection? Does your dvd have that also?

Thanking you, my TV has only one scart port and I do not have any possibility to connect it also to the DVD-player, my DVD-player has only one scart port and can not be be connected to the Ontvanger scart port because it (ontvanger) is connected to my TV, regarding that the Ontvanger has only one scart port, in addition to, buying a scart cable  with two ports does not work because ontvanget’s signal (being turned off also) and DVD-player ‘s signal  collide together, I proved it.

Thanking you , my TV has only one scart port; the TV has rca port(with three ports, colors of red , white and yellow also that I have not so far used it); the TV has not any hdmi port, it is old, Sony Trinitron Colour TV, my DVD-player has only one scart port, and other port with 4 points; one white(L); other one red(R); the third one is yellow(video) and the last one is black(digital Audio) is it a rca port? I have never used it,it seems to be able to use a scart-rca cable between the TV and the DVD-player, but I am not sure that it solves my problem, I have not proved yet, using only scart port, However I ordered it and I must wait for it by 23 December, thanking you again.

The yellow, white en red could be used for de dvd-player. If the dvd-player does not have these connections than you can use an scart → rca adapter with a rca cable with yellow, red en white on both sides. Or use a cable with on one side scart-plug and the other side rca plugs.

See for both options this google page.

Connect the kpn ontvanger with a scart - scart cable to the tv.

Your current tv is a tube tv and not widescreen? Than you do not use the delivered picture quality en those tv’s use a lot more power.

Best option. Modernise the tv. Ask Santa. Flatscreens can be bought from € 100. These are 32 inch, mostly HDready. They often have 2 hdmi ports en still one scart. (modern tv's usually don't have scart anymore).

Hi @shahram-m, I understand you're waiting for a delivery on the 23rd, will you inform me and @PeterG if everything is working again, when you've connected the scart-rca cable? 

Thanking you, I received it sooner, scart-rca cable, but it did not worked, I have sound, but I do not have any picture, I proved all other channel with Input mode button, but the problem was not solved.

@shahram-m I'm taking over this topic from my colleague @Maja_  because she isn't here for a couple of days. 
If the new cable doesn't work I am afraid the only option is to switch the SCART cable between the DVD-player and tv-receiver, depending on what u want to use.

Then you better use a SCART-switch. Like this one with 2 X in (DVD player and KPN settopbox) en 1 X out (to TV-SCART).

Thanking for your help and _respond, I have already ordered it, it is like your advised Scart switch, following link, that I am waiting to be delivered to me, but, if you see its picture there is a button on it, at the end the Scart switch, called RGB or RCB that I do not know what it is? Thanking you again.
https://www.kabeldirect.nl/scart-splitter-schakelaar-5-poorts-zilver.html?gclid=EAIaIQobChMI4smhh_3D5gIVTLTtCh0dfwzLEAQYBSABEgI7mPD_BwE

RGB is a slightly better picturequality than standard CVBS.
Both standards are supported by SCART. But not al TV's support RGB.

A DVD player can be set to RGB in his menu. I don’t know if the KPN settopbox supports RGB.

Button pushed in the switch works with RGB. Not in it is standard video (CVBS).

@shahram-m Were you able to solve the problem? Please let us know.