Circuit diagram etc for panasonic VCR - UK Vintage Radio Repair and Restoration Discussion Forum

Oldcodger · 3rd Mar 2016, 12:42 am

As stated. i've put it in modern ,as it's possibly less than 15 year old. Problem is suspect PSU failure as it seems dead. Internal fuse OK, but I've done no further checks.
Model is Panasonic NJ-SJ220 .
Any one any ideas where to look for circuit diagram ?

SiriusHardware · 3rd Mar 2016, 12:56 am

I don't, but ageing / failure of a small electrolytic placed very close to one of the heatsinks in the PSU unit is a common problem in some Panasonics.

It's in the SMPSU startup circuit, so the fault often manifests itself as failure to come back on after a power interruption even though it had been running - sometimes for years - before the power went off.

Not being familiar with this exact model, I can't say whether it's one of the ones which is prone to this problem.

Oldcodger · 3rd Mar 2016, 1:05 am

Thanks, Sirius- I can't remember when the VCR failed, but it seems likely as we had a power problem with our oven tripping RCD around this time. I've had the cover off to find as suspected that it's an SMPSU supply.

Red to black · 3rd Mar 2016, 12:29 pm

I will probably have access to the manual, however double check the model number as I am pretty certain all VCRs made by Panasonic start with model NV XXX, the XXX being letters and numbers.

dsergeant · 3rd Mar 2016, 7:12 pm

There is an NVSJ220, this is probably the one you have.
Dave

Oldcodger · 6th Mar 2016, 1:22 am

Just had a second look. Not easy as Swimbo has consigned this to upstairs cupboard, possibly as first stage in "get rid" as has happened before. You are correct, Dave- I've copied it down wrong. It is in fact NV-SJ220 .

Red to black · 6th Mar 2016, 1:59 am

Ok, I will search for that model number, it will be tomorrow now as it is getting late

Red to black · 6th Mar 2016, 1:38 pm

Here is the PSU diagram attached, I can see that on this diagram a few possibilities for a dead machine.
This PSU uses high value resistors for start-up, R 1105,1106 both 1 Megohms in series are prime candidates to check.

A check on the series connected chain of 12K resistors, R 1103,4,8,10,17 and 1126 might also be worth while.

If you need the full manual then contact me via PM.

3rd Mar 2016, 12:42 am	#1
Oldcodger Nonode Join Date: Oct 2014 Location: West Midlands, UK. Posts: 2,176	Circuit diagram etc for panasonic VCR As stated. i've put it in modern ,as it's possibly less than 15 year old. Problem is suspect PSU failure as it seems dead. Internal fuse OK, but I've done no further checks. Model is Panasonic NJ-SJ220 . Any one any ideas where to look for circuit diagram ?

3rd Mar 2016, 12:56 am	#2
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,091	Re: Circuit diagram etc for panasonic VCR I don't, but ageing / failure of a small electrolytic placed very close to one of the heatsinks in the PSU unit is a common problem in some Panasonics. It's in the SMPSU startup circuit, so the fault often manifests itself as failure to come back on after a power interruption even though it had been running - sometimes for years - before the power went off. Not being familiar with this exact model, I can't say whether it's one of the ones which is prone to this problem.

3rd Mar 2016, 1:05 am	#3
Oldcodger Nonode Join Date: Oct 2014 Location: West Midlands, UK. Posts: 2,176	Re: Circuit diagram etc for panasonic VCR Thanks, Sirius- I can't remember when the VCR failed, but it seems likely as we had a power problem with our oven tripping RCD around this time. I've had the cover off to find as suspected that it's an SMPSU supply.

3rd Mar 2016, 12:29 pm	#4
Red to black Nonode Join Date: Mar 2010 Location: Sunderland, Tyne and Wear, UK. Posts: 2,432	Re: Circuit diagram etc for panasonic VCR I will probably have access to the manual, however double check the model number as I am pretty certain all VCRs made by Panasonic start with model NV XXX, the XXX being letters and numbers. __________________ I don't suffer from Insanity. I enjoy every minute of it.

3rd Mar 2016, 7:12 pm	#5
dsergeant Octode Join Date: Mar 2006 Location: Bracknell, Berkshire,UK. Posts: 1,156	Re: Circuit diagram etc for panasonic VCR There is an NVSJ220, this is probably the one you have. Dave

6th Mar 2016, 1:22 am	#6
Oldcodger Nonode Join Date: Oct 2014 Location: West Midlands, UK. Posts: 2,176	Re: Circuit diagram etc for panasonic VCR Just had a second look. Not easy as Swimbo has consigned this to upstairs cupboard, possibly as first stage in "get rid" as has happened before. You are correct, Dave- I've copied it down wrong. It is in fact NV-SJ220 .

6th Mar 2016, 1:59 am	#7
Red to black Nonode Join Date: Mar 2010 Location: Sunderland, Tyne and Wear, UK. Posts: 2,432	Re: Circuit diagram etc for panasonic VCR Ok, I will search for that model number, it will be tomorrow now as it is getting late __________________ I don't suffer from Insanity. I enjoy every minute of it.