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NOTE: This decoder is obsolete. Most accessories and modifications mentioned on this page are no longer available.


Information for Philips CTU900 D2Mac cable TV - satellite - decoder

(CTU916 notes included, below)

The CTU900 is actually a D2Mac cable TV box. It was not intended for use with a satellite receiver and, as a result, has some inherent problems which have been solved by a BBC video engineer. He has given permission to publish this information here. If you copy this you MUST please also copy the reference to this web site. Not only does this create extra business for me but it also gives the reader a chance to come back here for the latest updates.

The CTU900 will work as a D2Mac decoder with some satellite receivers but there is no guarantee that it will work with yours. As it stands, it requires a MAC deemphasised (=filtered) baseband signal feeding into pin 20 of its VCR scart socket and the (hopefully) decoded baseband signal will come out of pin 19. The extracted righ and left audio also come out of the VCR scart socket on pins 1 and 3, as is usual.

A satellite receiver normally monitors the voltage on pin 8 of the scart socket. If this voltage goes "high" (= 12 volts) the receiver assumes that the decoder is now sending out a clear signal, so the receiver switches its input from its own tuner circuit to the decoder scart instead. It is sending its baseband OUT all the time but it looks for it coming BACK only when pin 8 goes high. Since the CTU900 does not put a voltage on pin 8 of its VCR scart socket, this system can not work. Consequently, you have two options:

1. Set your receiver so it *always* looks for the external AV input on the D2Mac channels or
2. Modify the CTU900 so it controls the voltage on pin 8 (see below).

The CTU900 is mostly held together with moulded clips. Remove the three rear panel screws, unclip the metal panel and take it off. Now you can see the other plastic clips which hold the base and cover together. These are underneath near the front. There is one central clip and one near each side. Release these and the front panel and top panel will slide forward away from the base panel. Take care!

Inside, you will see the D2Mac board mounted on pillars. Squeeze the tips of the four pillars with pliers and lift the D2Mac board up gently off the connector pins.


Thanks for the prompt service yet again !! :o)

Regarding the Philips CTU 916 D2Mac Decoder: the fan was mounted vertically onto the PCB with silicone RTV so that it blows across the PSU. The -ve was picked up next to the D2Mac board ground (Single grey cable) and soldered to ground side of diode 6506 this being the nearest solder point. The +ve was picked up at one of the 3 diodes next to the PSU , diode 5654 gave me 12.58v and I used your 110ohm resistor to drop the speed /noise of the fan


Steve Lawson

1. The CTU900 will not work with certain cards.

The cure is quite simple. If you look at the card slot unit on the front panel, you will see a ribbon cable which connects it to the main board. Just in front of the ribbon cable is a link wire marked 9202. Solder a 56R resistor across this link wire then cut the link in the middle so it leaves the resistor in circuit.

Another point has come to my attention regarding the replacement of link 9202 with 56R (original 39R suggestion did not always work), in the card reader's Vcc to card: The "multimac" remote control update of cards may not work. The original resistor was added because a certain late night programme had a batch of faulty?? cards, but remote control update folk will have to replace the link.

2. The Picture is "grainy".

On the D2Mac board, locate the TEA6420 I.C. The front right corner pin is number 1. About 12mm further to the right is a tubular electrolytic capacitor labelled C2341. Solder a 56pF capacitor from TEA6420 pin 1 to the nearest wire of C2341 (doesn't matter which end).

3. The Picture "flickers".

On the D2Mac board, locate capacitor C2327. This is a 0.47uF block polyester capacitor (situated between two electrolytics) about 10mm x 6mm. Remove it and replace it with 100nF/63v polyester capacitor. Of course you can adjust this value: try 220nF or 68nF if flicker still exists

4. I can't get a picture because the CTU900 won't give 12v on pin 8 of the Scart.

On the main board next to the TV Scart socket, locate R3122 (75R resistor). Cut one wire so R3122 is not connected. Now solder a wire from pin 20 on the TV Scart socket to pin 20 on the VCR Scart socket. Connect the satellite receiver decoder socket to the CTU900 TV Scart socket. With the CTU900 in standby you can watch normal PAL programmes. To descramble a D2Mac channel simply turn the CTU900 on. Note: the TV "PAL RGB" option under Menu - Install - TV must be set to "PAL".

5. Service Menu

Enter by pressing [TV DEC] [P+] [P-] [Clock-button] [I-II]. Complete each adjustment by pressing "OK". Exit by pressing "Standby". VCO adjust is code 150. BER (Bit Error Rate) is code 200. Drives and cut offs for colour can be accessed by code 170 but BEWARE: once you enter code 170, all cutoffs are reset to FF - even if you don't change anything! So, unless your colour balance is very very bad, DON'T enter code 170. The service CODES are the same as those used in the FilmNet BBD-901 decoder.

Note: "CTU916 twin cardreader Visiopass" unit. (We incorrectly used to call them "twin card CTU900s").

The sequence to enter the service menu is : "Aux"-- "Up" ( in 4 button Quad)-- "Down" (in 4 button quad)-- "Envoi"-- "Ret". Use "Visiopass" to exit. Normal Phillips codes seem to apply eg, 150 for VCO, 170 for cutoffs and drives--- Beware! This one defaults to cutoffs at "FF" so you must have a test card and an oscilloscope to set up!!! DO NOT enter code "170" !!!!

6. Where do I buy the parts for these modifications?


7. Who can do the work for me?

ASTRATECH in Swansea sell CTU900 already upgraded. Phone (01792) 701719 for prices. Please DON'T expect them to discuss modifications or technical matters. They specialise in selling new and used receivers and new satellite equipment. See their advert near the end of this page.

SATFIX in Swansea offer a full range of modifications for the CTU900.
They also specialise in D2Mac receiver repairs.
To arrange for them to do the work, phone (01792) 781673
Note: They will NOT supply parts or give you technical help so please do not contact them unless you want your CTU900 professionally upgraded. They may not accept any decoder for repair if it has been messed with. If you can carry out the modifications yourself, that's fine, but if you mess it up, don't expect SATFIX or SATCURE to bail you out.

8. Is there an English language manual?

Yes. See advert further down this page.

And Satellite Surplus in Teford can supply a useful information sheet.
(01952) 598173

The following stuff is untested and I can't answer questions on it because I don't know the answer!

9. PAL baseband mod

>I'm just about to buy one of these decoders, but have been put off by the
>high cost of the pictures mods when I know that I could do them myself if I
>knew what they entailed.
>Thanks to you - and Ken Hodges - I now know how to do this. *But* there's
>a single fly in the ointment: I need a PAL baseband o/p to work with my
>Grundig GRD200-clone (a JVC TU-C200) IRD.
>Is there any chance of this mod appearing at some time in the nearish
>future? (Basically, there's no point me doing the picture mods myself if I
>have to pay someone just for the PAL baseband mod.)

The reason I didn't initially post the rest of the mods is that I have not personally tried them. I've had to "translate" Ken's descriptions into something understandable and I can't do that without the unit on the bench so I can see what the heck he's writing about! (Ken gets a little technical and uses abbreviations). The PAL mod, however, looks fairly simple so here it is:

Solder the two ends of a 1k resistor to the two ends of a 470pF capacitor (so they are now connected in parallel. I will call this pair of components "XX".
Remove R3051 from the main board and fit "XX" instead.
Solder a 300R resistor to the end of "XX" which is nearest to the centre of the board.
Solder the other wire of this 300R resistor to any 0 volts point.

That's it but he goes on to say (and this is a translation..) "I disconnected the VCR remote control Phono socket to use as a switch so that I could select MAC or PAL baseband externally by inserting a phono shorting plug. I did this by removing link 9574 and cutting zener 6056. Then I wired chassis end of 300R to the phono socket inner connection."

10. Flat baseband mod

Same comments as above:

Solder the two ends of a 1k resistor to the two ends of a 470pF capacitor (so they are now connected in parallel. I will call this pair of components "XX".
Remove R3051 from the main board and fit "XX" instead.
Solder a 300R resistor to the end of "XX" which is nearest to the centre of the board.
Solder the other wire of this 300R resistor to any 0 volts point.

That's it but he goes on to say (and this is a translation..) "I disconnected the VCR remote control Phono socket to use as a switch so that I could select MAC or PAL baseband externally by inserting a phono shorting plug. I did this by removing link 9574 and cutting zener 6056. Then I wired chassis end of 560R+180pF to the phono socket inner connection."

PAL, Mac and Flat

If you want access to all three of these, you'll have to fit a switch and figure it out from the above!

11. The Ultimate Auto Mac switching

(I haven't tried this so I'm simply copying what Ken wrote).

On the main board next to the TV Scart socket, locate R3122 (75R resistor). Cut one wire so R3122 is not connected. Now solder a wire from pin 20 on the TV Scart socket to pin 20 on the VCR Scart socket.

Remove resistor R3062 (220R to VCR Scart pin 8) and link pin 8 on VCR Scart socket to pin 8 on TV Scart socket. (This allows the use of either Scart socket).

Cut R3083 (56k) at end furthest away from Scarts and wire the cut end to R3068 (68R) at end furthest away from the Scarts (don't cut R3068).

(This mod is using TV Scart pin 16 - fast blanking - to switch Scart pin 8 to 12v when decoder is actually decoding a MAC signal.)

Ensure that "RGB" is selected under "Menu" "Installation" "TV" "PAL/RGB".

The VCR Scart must be used for normal "PAL" including recording. The TV Scart can be used for those who have "RGB" capable TV sets where the host satellite receiver is capable of linking RGB through AND uses Scart leads. Beware!... "RGB" will cause loss of menus on Pace receivers while receiving MAC signals.

You might also want to do the following mod (you might not when you've read it!)

To keep PAL signal on pin 19 of TV Scart even when "RGB" is selected:

1. Remove link 9025.
2. Cut track on SMD R3093/R3094 side of C2020 (470nF) - (SMD resistors are both 470R).
3. Link SMD R3093 (150R)/R3077 (120R) [pad from pin 27 on header from Mac board] to C2819 (470nF) end of removed link 9025 and to C2020 (470nF) cut track end.

(Hey I'm English and *I* don't understand it).

Thanks to Francesco Benetti for correcting a mistake :o)
(His English is a darn sight better than my Italian!)

Dear Martin.

Once again your expertise has solved my problems.
I've fitted your "miniature silent fans" in my Pace MSS300 and the Phillips decoder, dropped the voltage with the resistors till they were just running and starting ok. The difference in running temperatures is tremendous.

Everyone who owns a CTU900 or a Pace Receiver MUST fit one of these fans.

Many thanks, especially for your patience.

Tommy O'Connor


I am pleased to let you know that our 2 slot upgrade for the CTU900 is now ready.
Basically, the adaptor needs to be fitted/installed in line with the ribbon connector which connects the main board and the card reader board + 3 wires connected elsewhere (and of course another card reader needs to be soldered in ).

Full instructions supplied with pictures showing installation if you want to DIY it.
You will need to fairly competent with a soldering iron.

DIY kit £29 + £2.50 for P+P = Total £31.50

or Fitted price £45 inc return postage.

Interested? Any questions ?

either - Order by phone on 01733 340707 - ask for Gavin

or - Email Me
GTaylor204 <>

or send your CTU900 with 45, (and your address of course) to

Gavin Taylor
415 Lincoln Road

Payment by Credit card, Switch, Delta, Cheque, Postal order or Cash.

Thanks to Chris Webster for writing the software to make the 2 card mod possible !

(Please contact Gavin direct. SatCure has no connection with this company)

English Language USER MANUAL

The manual explains how to get your decoder up and running. It also explains how to enter Multi Mac keys for those people with a home-update card. This manual is a MUST for any CTU900 owner!

To order your User Manual, please post £6.00 to:

14 The Wardens Avenue
Allesley Village

(Please contact David direct. SatCure has no connection with this company)

Questions and Useful Tips:

Converting Philips Remote Control

I have a question. I have bought a CTU900/00 d2mac decoder without a remote control. I hope you can help me with the following tech. question:

Can you tell me which IC drives the I/R signal? ( I hope it is rc5 standard like SAA 3006 or SAA 3010 or SAA 3027).

If so can you tell me which system matrix is used. (z0 to z3 -- dr0 to dr7) ( example TV signal = z0-dr0)

CTU900/00 must be z?-dr?

I have found it myself!

It is rc5 code by Philips system.

Matrix z1 to dr0 (address 08)

If someone else has a question about it you can simply change your Philips TV remote control to ctu900/00 remote control.

Change link z0 to z1 and you have it


>Hi Martin, very good web-site, very informative
>I just thought I would email you a mod I have done to my Phillips CTU900
>As you may know these units can run rather hot, even in stand by mode
>I fitted a miniature fan into the lid of the CTU 900 in the grill by the
>PSU on the top right hand corner and connected the 0v lead to jumper 9511
>and the 12v lead to jumper 9581.
>The CTU900 now runs nice and cool

(MP: See advert for miniature cooling fan kit on the SatCure kits page)


>I am also using my CTU900 with the PAL base band mod with my Nokia SAT800
>but I found the Nokia was giving to much video signal to the CTU900
>resulting in bleeding on bright whites so I connected a 1k preset pot in
>the video line between the two.
>Like so ;
>Video from SAT800 0-----------------
> |
> 1k Preset | |ß-------------0 Video to
> |
> GND 0----------------------------------0 GND
>I then adjust the preset so that the bleeding on bright whites disappeared,
>it also got rid of crackling on the audio if there was a black or nearly
>black picture.
>If you think this may be useful to other CTU900 owners you may add this
>email to your CTU900 document
>And thanks again for a good site

>After receiving the unit I switched one of the choices in a menu to D2MAC
>from PAL and now I cannot get a picture at all. Which sequence of key
>presses will get me out of this hole?
>I use Scart between my Pace MSS508IP and CTU900.
>Please help.

Oh, boy. Now I even have to read the User Manual to you :o(
On page 15 it tells you to press MENU. (This gets you the menu).
As you can see from the nice picture on page 15, "Installation of decoder" is on the fourth line down so you press the cursor DOWN button three times to get there.
Press OK. That gets you into the installation menu.
Now skip to page 43 where there is a pretty picture of the Installation menu.
PAL/MAC is on the third line down so you press the DOWN arrow twice to get there.
Now press the RIGHT arrow to alter it MAC -> PAL or whatever.
To exit press MENU then OFF.
Dear Martin,

Just to let you know that I have carried out mods 1, 2, 3, and 11 (Auto Mac switching) (as per page ), and they all work fine. Now I can leave my receiver channel setup in AUTO mode for input, and the CTU900 will switch it as necessary when receiving a Mac signal.


Thanks, Paul. Glad to hear there's someone out there who can follow instructions! :o)

>Hi, Martin. Here's hoping you can offer some advice.
>A number of weeks ago a Philips d2 mac decoder model CTU900 was
>purchased new from Satellite Solutions (Congleton).
>It worked / works well with an old Pace 9200 series receiver.
>(having obtained the reqd card) & tuned to intelsat etc.
>connection made via a 21 pin scart lead. & configured the menu as ext
>decoder etc etc.
>As this receiver is getting a little tired a new receiver etc. was
>recently purchased. A Nokia Satscan 1800, with 80cm steerable dish.
>Upon connecting the d2 mac to this receiver it is as if the video is not
>been routed through the decoder. The menu / set up seems to be
>configured corectly on the sat receiver.
>Having questioned sat solutions about this problem (having purchased
>both items from there) we have drawn a blank.
>The technical man is currently unavailable when we want him!
>Our d2 mac instruction sheet ( CTU900 ) mentions a slider switch on the
>rear to select differing base band inputs. This switch does not appear
>on our decoder (instruction sheet has company name "The perfect signal
>Ltd" printed on it. maybe importers name ??????? who knows?
>It would appear that the nokia is performing in a different way from the
>old Pace 9200 which definitely works ok with d2 mac.
>Have you any experience of such problems and if so can you educate us
>accordingly, or should we refrain from such foolish activities?
>Many thanks.

Hi, Steve,

Please read the Nokia SAT1700 FAQ (includes notes on SAT1800 decoder connections) and the CTU900 FAQ

Kind Regards,

> Hi Martin. We took a look at your FAQ'S on your site and thankfully
> found the answer. We carried out the baseband mods to the philips
> CTU900 as advised and it came good for us. One silly thing that
> fooled us was that, when we had set the modified equipment up, the
> osd message said "card poorly inserted" & it did not decode. The
> answer was that the card has to go in downside up, or is that upside
> down? when compared with a sat receiver/decoder. The contacts have
> to face upwards. Strange but true. We will in due course be sending
> you a variety of unused stamps as a thank you.

From Nat:
>The file on modifications for the Philips CTU 900, how much of it is
>applicable to the philips CTU902?
>I spoke to someone at T.P.S. (in what satellite) and they said the
>picture can be modified to output RGB on the scart, as the picture is a
>bit grainy at the moment. Do you know of any mods for the CTU902?
>If not, can you forward this on to someone who may ?

YES, Ken's reply is below :o)

Right: The CTU 902 is a close cousin to the Visiopass even the software from a Visiopass will run in a 902. (Although remote control codes are different).
The main differences are a PAL coder fitted (instead of a secam coder - the pal coder board was fitted after they were shipped into UK) and of course a cable tuner only - Visiopasses also had a sat tuner option.

First, regarding "coarse noise" : Make sure you are feeding "MAC BB from the host satellite receiver. If you only have "Flat BB" available, replace (R) 3028 (100R) with a 330R and at inboard end (junction to [C] 2007 100nF) connect a series 560R-180pF to chassis. Of course a weak signal as Martin states will give noise.

As regards using the "Tv" scart to get RGB: it's ok but pin 19 has mixed syncs on it in the "RGB" state the same as the CTU900, and the BB must go in on "VCR" (Magnetophone) scart.

I modified quite a number of Visiopasses to do "the full works" a la CTU900 but I never wrote the mods down - I assume the mods will directly fit the 902 as well, but I would have to get one on the bench to refine if required.
andre strijbos wrote:

> Since I haven't got a remote control with the decoder ,could anybody let
> me know the type number of the remote control (RC....) for the CTU900
> decoder?. There's also a part number in the battery housing (under the
> batteries).
> Tnx and happy viewing.........

0P009527 (they could be 'O' not Zero!)



Paul 'chikken'wrote
>Ive just entered the world of D2Mac stuff, having
>purchased a Phillips CTU900 decoder.
>I got a small white smart card with the decoder which
>decodes everything except the Canal+ channels.
>I get the message 'U hebt geen rechten', what does
>this mean (incase you hadnt guessed the menus are not
>exactly in english!)
>One last thing, my decoder seems to switch between EC-M/S2 ok, however
>sometimes sound will not come back, but a on-off will restore it. Any

The following was posted by mav months ago.


How to connect your decoder

Plug your scart lead from the decoder socket or your receiver to the
VCR socket of the decoder. Plug the decoder in to the mains socket.
Select channel 0 with the decoder remote control ( the front of the
decoder should display AU for auxillary). Tune to a d2mac station. If
the receiver has been set up correctly you should get a colour
scrambled picture generally it is green in colour. Insert your card
into the left hand card slot with the silver or gold contacts
uppermost (with a pirate card this will generally be with the chips
upside down).

How to change the onscreen menu into English

Press MENU on the decoder remote control
Press OK
Press OK
Press OK
Press OFF

For details of how to remote update your card after a key change then please see SatGod's code update guide...

>to access the ctu900 from philips you must enter first the [menu]
>buttom and then the buttoms as under point 5 in you page ctu900.htm
>there are decoders that wont accessable.
>john aalten

From the above, I think he is attempting to enter the "Service" menus after
pressing the "Menu" button on the remote control. This won't work reliably.
Service menu must be entered from "normal" picture. [Tv-Dec] [P+] (get
correct button) [P-] [Clock] [1-11].

Cheers, Ken Hodges.

Hi martin My friends CTU900 developed a power fault a while back. The absence of a circuit diagram made the job a little tricky. Fortunately I had a working unit to refer to. The fault symptom was "Dead, no display on the front panel". This unit is a pig to get into. Once opened the first time you can then see how you should have opened it . The way in is through the back panel: first remove all screws, preferably throw them away and use real screws to make it easier for the next guy cos they are the torx #10 type. Press the top slightly towards the front of the decoder. This should allow the top cover to separate from the rear metal panel . Then press the plastic lugs on the lower section of the rear panel - one located each side. This allows the black rear panel to be removed. Now using a torch and a long screwdriver (the longer the better) locate the plastic lug on each side of the top case and use the screwdriver to prise it inwards then slide the top slightly backwards; repeat for the other side. Then the top should slide backwards and off with hopefully no plastic broken.

THE FAULT: Comparing voltages revealed that the 5 volt supply, located on the the main pcb in the PSU section at the front, was low - about 2 volts. Attempts to trace it proved difficult but sanity prevailed and the fault proved to be a faulty 1 ohm resistor ref 3648 and a 5v1 Zener diode ref 6651. Once the components were replaced the unit came back to life. The biggest job with the ctu900 is getting into the thing. Hope this helps some poor soul.
Regards, Patrick Hannon

Philips STU3601 and Philips CTU900

I managed to link these two together to get D2MAC signal:
It was all very easy in the end. The usual scart connections and the only difficulty:

The philips STU3601,

  • On first menu choose INSTAL then DECODER.
  • DECODER must be MANUAL

after that all works wonderfully well.

Cheers, Brian Priest

>I have a question about D2MAC, I recently got a
>Phillips CTU900 box, I have a couple of questions looking at your web site
>regarding Pin 8.
>1. Your great info states modifications for this box because of the non
>switching line from the box to the Sat box (in this case a MSS500), anyhow
>what I have done is to cut pin 8 in the SCART lead. I then set the MSS500
>and set each D2MAC channel for force AV2 under the decoder section setup
>instead of Auto, this works fine. This means that I can get both std PAL
>pictures with Auto enabled, and D2MAC pictures from the tuned Mac channels.
>Also means no need to goto stdby mode for the decoder to watch PAL
>programmes. My question is anything wrong with doing it this way or have I
>missed something, does this degrade and quality of picture etc? or is there
>any tolerance I have missed? It seems to work very well?

No, it's fine. It won't affect the picture.

CTU916 ADVERT From: "" <>

DIY upgrade kits for the CTU916 FRANCE VISIOPASS twin card decoder.

1/ ENGLISH menu
2/ remove flicker
3/ PAL output
4/ lets you use official rdv cards (ser 5)
5/PAL input (NOKIA etc)

£18 & £2 postage (please note: soldering skills required)


TEL +44 1792 701719


Note: Please contact ASTRATECH for this conversion kit.

I just got the visiopass Philips CTU916 d2mac decoder but there are no instructions with it. Can you please help me in using it ? Most important of all please tell me how to hook it up and how to use it.

I need to connect it to my Echostar LT-8700 Analog satellite receiver.
It has in the back a decoder scart connector, but in which of the three scarts of the ctu916 should I connect it ?

Connect the decoder scart socket on back of your Echostar to the AUX 2 scart on rear of CTU916. You can't turn on the power to the CTU916 with the remote, or while any cards are inserted. To power on, remove (or slightly pull out) any cards, then press and hold in the small button with the "-" minus sign on it, until the blue display comes on. Ensure it is set to AU, by pressing the + or - buttons until it does. You can then insert any cards, initially just insert one card, and I've found the card slot on the left gives the best results.

Then go through the channels on your Echostar until you have TV3, TV1000 or whatever your card is supposed to decode. You should see a typical scrambled D2MAC channel, which should decode after a few seconds, if it doesn't an error message will usually come on the screen.

Colin Blanshard Withers

I just got the visiopass Philips CTU916 d2mac decoder but the pictures are only black and white!

How do I change the SECAM to PAL?

Read this page

CTU900circuit board layout

This information is given in good faith, based on several years of workshop experience involving thousands of repairs. No responsibility will be accepted for any death, damage or injury caused either directly or indirectly by the use of this information. The reader should check the facts himself. It is assumed and stressed that the reader will be familiar with good, safe, electronic workshop practice and will be familiar with all tools, components and terms used. If there is any doubt about the reader's ability to carry out such work competently and safely, the work should be referred to a specialist engineer.

COPYRIGHT 1998 Ken Hodges (Author)
This file may be downloaded for private and personal use but NO part of it may be published in any form without the prior permission of the author.


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Copyright ©1997 SatCure and Ken Hodges
Version 1.9 updated on September 29, 2000
This file may be downloaded for private and personal use but NO part of it may be published in any form without the prior permission of the authors.

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