Philips N1700 modules - UK Vintage Radio Repair and Restoration Discussion Forum

TonyDuell · 24th Jun 2022, 10:28 am

Some time back I asked about internal information on the little plug-in modules in the Philips N1700 VCR. Since this information seems to be impossible to find, I've traced out the circuits of the modules in my machine.

I suspect there may well be other versions though. The TDA2700 chip is not used in my machine but it would seem indeal for one of the chroma frequency changer oscillators. Perhaps there's a later version that uses it.

Anyway, attached to this message are the IF-related modules.

TonyDuell · 24th Jun 2022, 10:29 am

Here are the audio recording/playback module and the signal combiner at the input to the modulator

TonyDuell · 24th Jun 2022, 10:30 am

The chroma modules

TonyDuell · 24th Jun 2022, 10:32 am

The video recording/playback FM modulator and demodulator on the little motherboard under the signal processing one.

TonyDuell · 24th Jun 2022, 10:34 am

And finally the modules on the servo board on top of the deck,

That's the lot, I am not going to attack the tuner or /UHF modulator.

af024 · 24th Jun 2022, 11:22 am

Wow! That's truly impressive. Top marks for stamina, dexterity and good eyesight!
This is so good. It will help tremendously in fault-finding down to component level. These modules are only going to get more and more scarce, so this detail is invaluable.

Thank you TonyDuell. Gold star!

Maarten · 24th Jun 2022, 6:44 pm

Nice! I always ike a good piece of reverse engineering! Especially when drawn by hand in a way that's as good or better than a CAD drawing.

Could you by any chance also post the 3103 xxx xxxxx numbers (should be on the same label a the 4822 numbers), as those will identify the exact version of the modules?

TonyDuell · 24th Jun 2022, 6:52 pm

I will have to take the machine apart again, which means finding some space on the bench, but yes, I can look for those numbers too.

TonyDuell · 24th Jun 2022, 6:57 pm

Quote:

Originally Posted by af024

Wow! That's truly impressive. Top marks for stamina, dexterity and good eyesight!

Even if it is 'blowing my own trumpet' which of course 'socienty frowns upon'. the obvious reply is this site :

http://www.hpcc.org/cdroms/schematics5.0/index.html

TonyDuell · 25th Jun 2022, 10:32 am

Quote:

Originally Posted by Maarten

Could you by any chance also post the 3103 xxx xxxxx numbers (should be on the same label a the 4822 numbers), as those will identify the exact version of the modules?

Here you are, I hope.

Note that this is the UK PAL version of the N1700 (so 6MHz intercarrier, etc), N1700/15

U219 3103 128 2090 3
U228 3103 128 2133 1
U230 3103 128 2132 2
U236 3103 128 2125 1
U237 3103 128 2124 5

U505 3103 128 2092 2
U506 3103 128 2093 3
U507 3103 128 2128 2
U508 3103 128 2094 3
U512E 3103 128 2079 5
U513E 3103 128 2080 6
U514 3103 128 2109 2
U515 3103 128 2110 3
U531 3103 128 2139 3
U539 3103 128 2113 4

U731 3103 128 2117 3
U732 3103 128 2118 2
U734 3103 128 2119 1

Maarten · 25th Jun 2022, 12:37 pm

Great, thanks! It's the last digit that indicates the revision level.

After the last digit reaches 9, the next revision gets an entirely new number. In most cases the first free number of which the first 8 digits are identical to those of the old number is chosen. If digits 9 through 11 reach 999, it gets a bit more complicated (just incrementing the 8th digit would often put it in another category, in this case changing a module into a transformer...).

HurtyAC · 30th Jun 2022, 1:28 pm

I would like to say you have done an excellent job reverse engineering those boards, well done, how long did this take you?? I did do the chroma module on N1502's using the TDA2700 chip in the chroma processing as in the day this was the most common module I had failures with, causing no chroma.

TonyDuell · 30th Jun 2022, 3:18 pm

The time taken : The more difficult modules (not necessarily the most complex, but the ones with circuitry I am not totally familiar with) took about a day each. For the simpler ones, I could do 2 in a day. The whole project took under 2 weeks and I was doing other things as well.

Chris55000 · 9th Jul 2022, 3:11 pm

That's now tempted me to buy an N1700 for myself, so I can follow on from Tony's job by producing the PCB Layout Drawings for them!

Are tapes still available in reasonable questions secondhand, and what about the video heads themselves?

Chris Williams

Chris55000 · 9th Jul 2022, 5:56 pm

PS!

I will be dealing with the tuner and modulator modules if I do go ahead with this project in the future!

Chris Williams

24th Jun 2022, 11:22 am	#6
af024 Octode Join Date: Jan 2003 Location: Ashby-de-la-Zouch (it's not by the sea) Posts: 1,255	Re: Philips N1700 modules Wow! That's truly impressive. Top marks for stamina, dexterity and good eyesight! This is so good. It will help tremendously in fault-finding down to component level. These modules are only going to get more and more scarce, so this detail is invaluable. Thank you TonyDuell. Gold star! __________________ Now where on earth did I remove that from?

24th Jun 2022, 6:44 pm	#7
Maarten Dekatron Join Date: Dec 2007 Location: Haarlem, Netherlands Posts: 4,199	Re: Philips N1700 modules Nice! I always ike a good piece of reverse engineering! Especially when drawn by hand in a way that's as good or better than a CAD drawing. Could you by any chance also post the 3103 xxx xxxxx numbers (should be on the same label a the 4822 numbers), as those will identify the exact version of the modules?

24th Jun 2022, 6:52 pm	#8
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,208	Re: Philips N1700 modules I will have to take the machine apart again, which means finding some space on the bench, but yes, I can look for those numbers too.

25th Jun 2022, 12:37 pm	#11
Maarten Dekatron Join Date: Dec 2007 Location: Haarlem, Netherlands Posts: 4,199	Re: Philips N1700 modules Great, thanks! It's the last digit that indicates the revision level. After the last digit reaches 9, the next revision gets an entirely new number. In most cases the first free number of which the first 8 digits are identical to those of the old number is chosen. If digits 9 through 11 reach 999, it gets a bit more complicated (just incrementing the 8th digit would often put it in another category, in this case changing a module into a transformer...). Last edited by Maarten; 25th Jun 2022 at 12:46 pm.

30th Jun 2022, 1:28 pm	#12
HurtyAC Tetrode Join Date: May 2009 Location: Ware, Hertfordshire, UK. Posts: 75	Re: Philips N1700 modules I would like to say you have done an excellent job reverse engineering those boards, well done, how long did this take you?? I did do the chroma module on N1502's using the TDA2700 chip in the chroma processing as in the day this was the most common module I had failures with, causing no chroma.

30th Jun 2022, 3:18 pm	#13
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,208	Re: Philips N1700 modules The time taken : The more difficult modules (not necessarily the most complex, but the ones with circuitry I am not totally familiar with) took about a day each. For the simpler ones, I could do 2 in a day. The whole project took under 2 weeks and I was doing other things as well.

9th Jul 2022, 3:11 pm	#14
Chris55000 Nonode Join Date: Aug 2007 Location: Walsall Wood, Aldridge, Walsall, UK. Posts: 2,870	Re: Philips N1700 modules That's now tempted me to buy an N1700 for myself, so I can follow on from Tony's job by producing the PCB Layout Drawings for them! Are tapes still available in reasonable questions secondhand, and what about the video heads themselves? Chris Williams __________________ It's an enigma, that's what it is! This thing's not fixed because it doesn't want to be fixed!

9th Jul 2022, 5:56 pm	#15
Chris55000 Nonode Join Date: Aug 2007 Location: Walsall Wood, Aldridge, Walsall, UK. Posts: 2,870	Re: Philips N1700 modules PS! I will be dealing with the tuner and modulator modules if I do go ahead with this project in the future! Chris Williams __________________ It's an enigma, that's what it is! This thing's not fixed because it doesn't want to be fixed!