Sony Trinitron CRT TV fault - UK Vintage Radio Repair and Restoration Discussion Forum

phildil · 24th Jun 2022, 10:30 pm

Hello Everyone,

After two decades service, my Sony CRT Trinitron TV is now faulty.

Model: KV-32CS70B

When powered up it goes into standby and doesn't exit the diagnostic stage. The red flashing light sequence is initially two (over current protection) then goes to three (over voltage protection) when the remote control ON button is pressed.

I'd like to save the TV from the tip ...erm the recycling centre.... if I can.

Can anyone help, please?

ta

phil

agardiner · 25th Jun 2022, 7:32 am

Have you carried out a good initial internal inspection? Maybe worn electrolytics in the power supply. Any bulging ones?

HamishBoxer · 25th Jun 2022, 8:39 am

I hope the 2 flashes is not loptx.

Welsh Anorak · 25th Jun 2022, 10:03 am

I think we have line output stage problems here. Firstly check the line output transistor for a short. Then if we're OK there turn on and see if you can hear (!) a rustle of EHT. If so then it can be the frame output IC loading the stage or, as said above, the LOPT.
Do also check for dry-joints on the regulators. Occasional capacitor failure, but not a go to on this chassis.

Funny how quickly you forget - saw it was a 32" and though 'oh, just a small one then'. Er, no, not in the days of CRTs!

Maarten · 25th Jun 2022, 10:59 am

The MCZ3001 IC or ICs would also break sometimes.

24th Jun 2022, 10:30 pm	#1
phildil Tetrode Join Date: Sep 2014 Location: London, UK. Posts: 93	Sony Trinitron CRT TV fault Hello Everyone, After two decades service, my Sony CRT Trinitron TV is now faulty. Model: KV-32CS70B When powered up it goes into standby and doesn't exit the diagnostic stage. The red flashing light sequence is initially two (over current protection) then goes to three (over voltage protection) when the remote control ON button is pressed. I'd like to save the TV from the tip ...erm the recycling centre.... if I can. Can anyone help, please? ta phil

25th Jun 2022, 7:32 am	#2
agardiner Heptode Join Date: Sep 2020 Location: Thetford, Norfolk, UK. Posts: 850	Re: Sony Trinitron CRT TV fault Have you carried out a good initial internal inspection? Maybe worn electrolytics in the power supply. Any bulging ones?

25th Jun 2022, 8:39 am	#3
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,487	Re: Sony Trinitron CRT TV fault I hope the 2 flashes is not loptx. __________________ G8JET BVWS Archivist and Member V.M.A.R.S

25th Jun 2022, 10:03 am	#4
Welsh Anorak Dekatron Join Date: Apr 2005 Location: North Wales, UK. Posts: 6,038	Re: Sony Trinitron CRT TV fault I think we have line output stage problems here. Firstly check the line output transistor for a short. Then if we're OK there turn on and see if you can hear (!) a rustle of EHT. If so then it can be the frame output IC loading the stage or, as said above, the LOPT. Do also check for dry-joints on the regulators. Occasional capacitor failure, but not a go to on this chassis. Funny how quickly you forget - saw it was a 32" and though 'oh, just a small one then'. Er, no, not in the days of CRTs! __________________ Glyn www.gdelectronics.wales

25th Jun 2022, 10:59 am	#5
Maarten Dekatron Join Date: Dec 2007 Location: Haarlem, Netherlands Posts: 3,592	Re: Sony Trinitron CRT TV fault The MCZ3001 IC or ICs would also break sometimes.