Hitachi CNP-190 tv info - UK Vintage Radio Repair and Restoration Discussion Forum

marcus 3500 · 9th Sep 2007, 3:42 pm

Hi all

Yesterday I thought I would have a quick look at this set from 1973: I thought it only needed a few caps; 100UF 160V etc that had leaked but last night after powering up there's no colour.
I do have the service manual for this set, but have spent most of today looking for it with no luck

As can be seen with last night's proms, the blue flares to the right with a high brightness setting - worn tube?

What I need to know is how to disable the colour killer.

Regards

Marcus........

Welsh Anorak · 9th Sep 2007, 3:59 pm

Hi Marcus
Hmmm....at least it isn't the previous model with the horrendous PAL/NTSC decoder! I'll have a look tomorrow and see what I can find - there's bound to be a manual somewhere. Meanwhile, I see TR25, C514 and C533 can cause trrouble. I'd leave the set running - that should cheer the tube up and maybe coax the decoder back to life!
Also check the HT - it can drift alarmingly.
I'd forgotten the CRT is fitted upside down - but then you'd be used to that, wouldn't you!
Glyn

Steve_P · 9th Sep 2007, 4:04 pm

Put this on Crosshatch and see what shows up. Looking at the pictures, I notice that on the left of that fellow's sleeve it looks green.

Cheers,

Steve P

Welsh Anorak · 9th Sep 2007, 4:13 pm

Hi
I think that's the tube - the focus/convergence were never that clever on these at high brightness levels. Do check the channel selectors (though I'm sure you have already) as the tuning's quite critical.
Glyn

marcus 3500 · 9th Sep 2007, 7:25 pm

Cheers Glyn, Steve

The set's in bits at the mo so I can't put it on a crosshatch just yet. TR25 and TR5 are the same type; 2SA15.
I've swapped them over, and the fault was the same.
I'm going to try the caps you mention Glyn - I've found the values in Fault Finding Guide Volume 1 (see pic)
cheers for now

Regards

Marcus..........

Mike Phelan · 10th Sep 2007, 8:12 am

Marcus
If the blue flaring doesn't cure itself after a good run, swap the RGB leads to the CRT around; that will prove if it is the CRT (it sure looks like it)

You may not want to bother with sorting the chroma fault then.

Mikey405 · 10th Sep 2007, 4:58 pm

From memory, I seem to recall that these had those horrible low focus voltage tubes in. If the tube is duff and doesn't come up by itself, it may be worth giving it a go with a tube bonker. I can bring one up next time I come that way if you like (along with the DVD that I STILL haven't sent you - doh.)

Having said that, yours seems to have a much better tube in it than the one I had which was utterly appalling. The tuner twiddlers were all a bit knackered in mine too and it would constantly drift off tune until you touched the twiddlers and then it would splutter about a bit and sometimes come back. No amount of dismantling and cleaning seemed to cure the problem though.

From Mike.

marcus 3500 · 11th Sep 2007, 4:44 pm

Hi all

Hi Mike the picture is a lot better now it's been on for over 7 hours. It still flares with the brightness up full, and now I've got the colour to work - red flares too.

I'll put it on my tube tester if I can find the correct base.

The tube is 490DKB22 Delta gun

Sorry I was unable to get on here last night to post my progress, but I didn't finish getting the colour on the Hitachi till 8.30PM. By then, Carol said I should call it a day, and our son was waiting to go to bed and wanted a story.

In the end all this set wanted was a fuse

F903 315MA but I spent a good few hours finding this out.
Yesterday I found my service manual and decided to change C306,C269,C252,C509,C535,C538,C511, but still no colour; then I disabled the colour killer - still the same. I then checked the 12V line it was 9.6V.

I then found the 12V line comes from the lopt and checked its diode CR25 that read perfectly, but decided to swap it and its cap C722. The 12V line was now 9.8V.

After a quick coffee I thought it would be best to unhook one-by-one all of the connections to the 12V line: B1 then K2 and K8. The voltage only got up to 10.2Volts.

After more coffee and thinking that the 12 volts comes from the lopt. Maybe the HT is low it was 108V should be 120.5 volts. I should have taken Glyn's advice earlier to check the HT.
After slight adjustment of R911 it still stayed at 108V, I was about to take out the PSU but something made me check the fuses and F903 O/C; not black, but soft blown, so I guess it died of old age. Fit new fuse and adjust R911 for 120.5 volts and now full colour

The set's been on most of today without fault so it can now be put back together.

Regards

Marcus.........

9th Sep 2007, 3:42 pm	#1
marcus 3500 Retired Dormant Member Join Date: May 2006 Location: South Yorkshire, UK. Posts: 351	Hitachi CNP-190 tv info Hi all Yesterday I thought I would have a quick look at this set from 1973: I thought it only needed a few caps; 100UF 160V etc that had leaked but last night after powering up there's no colour. I do have the service manual for this set, but have spent most of today looking for it with no luck As can be seen with last night's proms, the blue flares to the right with a high brightness setting - worn tube? What I need to know is how to disable the colour killer. Regards Marcus........ Attached Thumbnails Last edited by Mike Phelan; 14th Jul 2008 at 11:42 am. Reason: S&P

9th Sep 2007, 3:59 pm	#2
Welsh Anorak Dekatron Join Date: Apr 2005 Location: North Wales, UK. Posts: 6,927	Re: Hitachi CNP-190 tv info Hi Marcus Hmmm....at least it isn't the previous model with the horrendous PAL/NTSC decoder! I'll have a look tomorrow and see what I can find - there's bound to be a manual somewhere. Meanwhile, I see TR25, C514 and C533 can cause trrouble. I'd leave the set running - that should cheer the tube up and maybe coax the decoder back to life! Also check the HT - it can drift alarmingly. I'd forgotten the CRT is fitted upside down - but then you'd be used to that, wouldn't you! Glyn

9th Sep 2007, 4:04 pm	#3
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Hitachi CNP-190 tv info Put this on Crosshatch and see what shows up. Looking at the pictures, I notice that on the left of that fellow's sleeve it looks green. Cheers, Steve P __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

9th Sep 2007, 4:13 pm	#4
Welsh Anorak Dekatron Join Date: Apr 2005 Location: North Wales, UK. Posts: 6,927	Re: Hitachi CNP-190 tv info Hi I think that's the tube - the focus/convergence were never that clever on these at high brightness levels. Do check the channel selectors (though I'm sure you have already) as the tuning's quite critical. Glyn

9th Sep 2007, 7:25 pm	#5
marcus 3500 Retired Dormant Member Join Date: May 2006 Location: South Yorkshire, UK. Posts: 351	Re: Hitachi CNP-190 tv info Cheers Glyn, Steve The set's in bits at the mo so I can't put it on a crosshatch just yet. TR25 and TR5 are the same type; 2SA15. I've swapped them over, and the fault was the same. I'm going to try the caps you mention Glyn - I've found the values in Fault Finding Guide Volume 1 (see pic) cheers for now Regards Marcus.......... Attached Thumbnails

10th Sep 2007, 8:12 am	#6
Mike Phelan Dekatron Join Date: Nov 2003 Location: Near Leeds, West Yorkshire, UK Posts: 4,609	Re: Hitachi CNP-190 tv info Marcus If the blue flaring doesn't cure itself after a good run, swap the RGB leads to the CRT around; that will prove if it is the CRT (it sure looks like it) You may not want to bother with sorting the chroma fault then. __________________ Mike.

10th Sep 2007, 4:58 pm	#7
Mikey405 Octode Join Date: Jul 2006 Location: Solihull, West Midlands and Beaford, Devon Posts: 1,626	Re: Hitachi CNP-190 tv info From memory, I seem to recall that these had those horrible low focus voltage tubes in. If the tube is duff and doesn't come up by itself, it may be worth giving it a go with a tube bonker. I can bring one up next time I come that way if you like (along with the DVD that I STILL haven't sent you - doh.) Having said that, yours seems to have a much better tube in it than the one I had which was utterly appalling. The tuner twiddlers were all a bit knackered in mine too and it would constantly drift off tune until you touched the twiddlers and then it would splutter about a bit and sometimes come back. No amount of dismantling and cleaning seemed to cure the problem though. From Mike. __________________ G7TRF

11th Sep 2007, 4:44 pm	#8
marcus 3500 Retired Dormant Member Join Date: May 2006 Location: South Yorkshire, UK. Posts: 351	Re: Hitachi CNP-190 tv info Hi all Hi Mike the picture is a lot better now it's been on for over 7 hours. It still flares with the brightness up full, and now I've got the colour to work - red flares too. I'll put it on my tube tester if I can find the correct base. The tube is 490DKB22 Delta gun Sorry I was unable to get on here last night to post my progress, but I didn't finish getting the colour on the Hitachi till 8.30PM. By then, Carol said I should call it a day, and our son was waiting to go to bed and wanted a story. In the end all this set wanted was a fuse F903 315MA but I spent a good few hours finding this out. Yesterday I found my service manual and decided to change C306,C269,C252,C509,C535,C538,C511, but still no colour; then I disabled the colour killer - still the same. I then checked the 12V line it was 9.6V. I then found the 12V line comes from the lopt and checked its diode CR25 that read perfectly, but decided to swap it and its cap C722. The 12V line was now 9.8V. After a quick coffee I thought it would be best to unhook one-by-one all of the connections to the 12V line: B1 then K2 and K8. The voltage only got up to 10.2Volts. After more coffee and thinking that the 12 volts comes from the lopt. Maybe the HT is low it was 108V should be 120.5 volts. I should have taken Glyn's advice earlier to check the HT. After slight adjustment of R911 it still stayed at 108V, I was about to take out the PSU but something made me check the fuses and F903 O/C; not black, but soft blown, so I guess it died of old age. Fit new fuse and adjust R911 for 120.5 volts and now full colour The set's been on most of today without fault so it can now be put back together. Regards Marcus......... Attached Thumbnails Last edited by marcus 3500; 11th Sep 2007 at 5:04 pm.