Sony TV5-303M / 1963 5" B&W TV - UK Vintage Radio Repair and Restoration Discussion Forum

jhalphen · 19th Feb 2006, 7:22 pm

Good day Gentlemen,

I have a little 5" Sony TV5-303M, this is the French & Euro version with 819 and 625 line standard. My local radio/TV repair shop has diagnosed it with a partial short circuit in the EHT transformer.

Failure symptom:
The TV5-303M can work fine for some time, then suddenly the picture shrinks horizontally & vertically with about a inch missing left & right, top & bottom. The TV has been partially recapped (power supply
section) and when this happens the 12V supply remains stable.When the shrinkage happens, the H out transistor gets really hot because of excessive power drain.

To repair it, I can either find the complete EHT assembly, Sony P/N1-353-001-02 (keep dreaming !) or buy a donor set with a healthy EHT transformer, for instance one which shows just a bright horizontal line
across the screen. Now these sets show up frequently on E-Bay US but I don't know if a US EHT assembly will work on my French set.

The US line frequency is 15750 Hz and ours at 625 is 15625 Hz, so no problem there. However I also use this set to demo 819 lines with the Aurora standards converter, and the H frequency at 819 is 20475 Hz.

Knowing this, do you think I can substitute a US EHT transformer or will it overheat at 20475 Hz ?

Of course if I had access to the Sony manual for the TV5-303W i.e. the US version, I could check the P/N and see if it is the same.

Many Thanks! in advance for your advice,

Best Regards

Danny · 19th Feb 2006, 11:16 pm

Hi
I would guess Sony used the same tranny and you wouldn't have a problem with the US tranny as the timebase is probably configured for this frequency.
The EHT would be higher at this line speed though, I reckon they have altered the timebase to cater for this.

I wonder if they used the LOPT from a more common model ?
Is it an encapsulated unit or could the overwind be changed?
Is it the same type as the 9" Sony dual or is it a more miniature type?.
Danny

FERNSEH · 20th Feb 2006, 12:32 am

Hello Jerome,
I've got a working TV9-90UB. Tomorrow, I could try supplying it with a 819 line UHF signal and after fiddling with the line frequency see what happens. I believe a 625/819 version of the TV9 was marketed in France.

Regards,
David.

oldeurope · 20th Feb 2006, 9:56 am

Hi Jhalphen,
please measure out the AC component at the pins of the EHT transformer.
Voltage and polarity of the H- pulse.
This makes it easyer to rewind it if neccessary.

Kind regards
Darius

jhalphen · 20th Feb 2006, 11:34 am

Hello Gentlemen,

Many Thanks! for your numerous replies.

To Danny : The EHT transformer is a highly miniaturized model. I will try to include pictures of the manual + the schematic. If this first attempt fails, I will have to make reduced versions of my scans. The EHT is hermetically sealed and the Sony manual specifically advises not to open it. My repair shop found that 2 of the closing tabs were partially open, probably the result of the sealing compound expanding because of excessive internal heat.

To Fernseh: Hello David, I am very grateful and extremely interested in your planned test of running a TV9-90UB at 819 lines. This TV was indeed sold in France under the reference TV9-90UM. Alas, in my 3000 B&W TV pictures in my library I cannot find a single one of this model ;-(

To Darius:
As this is my first contact with you please let me say that I am honoured that the great developer of so many innovative transcoding/modulating devices is taking an interest in my little problem.
Unfortunately Ii cannot answer your question as I left the Sony at the repair shop waiting for a donor EHT transformer.

Best Regards to all,

Jerome H

oldeurope · 20th Feb 2006, 12:46 pm

https://www.vintage-radio.net/forum/...ead.php?t=6768

look at #3 for the pics of the SONY 625/819.

Hi Jhalphen,
attached a link to some pics of my Sony.
Your EHT transformer looks like the one used in my camera viewfinder.
There are valves in the schematic but, in real live not.

You wrote:

"My repair shop found that 2 of the closing tabs were partially open..."

The interesting question is which tap must be opened to run the
transistor hot?
Maybe the Damper Diode goes o/c?

Kind regards
Darius

jhalphen · 20th Feb 2006, 2:33 pm

Hello Darius,

Thanks for the reply & for the link to your Sony CVM-90UM.

Interestingly, the seemingly physically identical set sold in France was model TV9-90UM. I have a photocopy of the complete Sony service manual (40 pages).

Reception is:
VHF, French F2, F4-F12
CCIR Western Europen : Belgian E2-E12
Italian B(E-4)
D(E-5)
H(E-10)

UHF, CCIR & French 21-69

Also the power supply is 110V/130V/220V.

To come back to the TV5-303M, maybe i didn't express myself correctly:

"My repair shop found that 2 of the closing tabs were partially open..."

By writing this I meant that the closed EHT "tin can" started to open itself from internal pressure. The metal tabs were pushed open, I did not mean that taps on the transformer windings were open.

You wrote:
"The interesting question is which tap must be opened to run the
transistor hot?

Er, sorry I don't understand. Could a bad damper diode produce excessive heating of the H out transistor and a picture size reduction in all 4 dimensions ?
The shop said "partially shorted turns on the EHT transformer, get a new one".
Do you think I should take the set back and change the damper diode before trying to chase a complete EHT assembly.
Should I get some 1DK1 rectifiers or can a solid state diode be substituted? If you could give me a reference (1N... or BY...) that would be a great help.

Before Ii go on any further I must say that i have had excellent service from this shop for several years and I respect their knowledge. This is a father/son operation and the father, in his 60s, has great experience of vintage electronics.

Thanks again for your help,

Best Regards

Jerome H

oldeurope · 20th Feb 2006, 3:29 pm

Quote:

Originally Posted by jhalphen

Hello Darius,

Interestingly, the seemingly physically identical set sold in France was model TV9-90UM. I have a photocopy of the complete Sony service manual (40 pages).

To come back to the TV5-303M, maybe i didn't express myself correctly:

"My repair shop found that 2 of the closing tabs were partially open..."

By writing this i meant that the closed EHT "tin can" started to open itself from internal pressure. The metal tabs were pushed open, I did not mean that taps on the transformer windings were open.

You wrote:
"The interesting question is which tap must be opened to run the
transistor hot?

Er, sorry i don't understand. Could a bad damper diode produce excessive heating of the H out transistor and a picture size reduction in all 4 dimensions ?
Thanks again for your help,

Best Regards

Jerome H

Hi Jerome,
I had to pay 25 Euros for the copies of the manual.
Ok that is live.

Ah sorry I thaught a connection in the transformer is the problem.
If you have a shorted winding, you need a new transformer.

Are sure you have this 1DK1 in your EHT Block?

Kind regards
Darius

jhalphen · 20th Feb 2006, 3:58 pm

Hello Darius,

Thanks for the reply.

Since a very long time i've had much respect for Sony's innovative electronics, so even when i didn't have the money to buy their products when new, i would get a copy of the schematics just to see how they worked. I didn't know that 30-40 years in the future with the magic of low cost standards converters and low power transmitters i would be able to operate TVs of foreign standards (US & CCIR) right here in Paris.

TV5-303M :
I did not open the HV "tin can" so i'm not sure of the 1DK1's presence. However this is a 1963 product and when i repaired one in 1975 it did have the 3 tube rectifiers.

To tell the story, from time to time i would hear arcing sounds. I inspected the TV in the dark to see sparks & saw none. Out of despair i opened the sealed EHT block. There was a blob of solder on one of the 1DK1s and when the humidity/temperature conditions were right, there would be a discharge between the tube's electrodes and the drop of solder. I removed the solder, filed the sharp points to a nice round shape, and the problem was solved.

I don't have this TV anymore. The one causing problems was purchased from E-Bay Germany last year. I purchased it as it had the very hard to find VUC-4U UHF converter. I try to make all my TVs work at least once per month to keep the electrolytics in good shape.

Best Regards

Jerome H

Heatercathodeshort · 20th Feb 2006, 7:13 pm

Hello,
Just a thought. I wondered if the original line output transformer was in fact faulty. You did mention that it worked for a while and then the scan reduced. Sounds more like a leaking capacitor or diode fed from one of the windings. It would be very frustrating to go to all this trouble just to discover the original was ok all the time...I know..I have done it! Regards JOHN.

jhalphen · 20th Feb 2006, 7:44 pm

Hello John,

Thanks! for your advice. Maybe time for me to retrieve the set from the shop, find some 1DK1s and 3 x 500 pF 6kV caps.

From a quick look by a US friend into the Stateside version of the 5-303, the flyback transformer has a different P/N than mine.

I purchased the tubes previously here : http://www.vacuumtubes.com

6KV caps ? RadioSpares ? Mouser ? got a got Euro source perhaps ?

Thanks for your help

Best Regards

Jerome H

19th Feb 2006, 7:22 pm	#1
jhalphen Hexode Join Date: Jul 2004 Location: Paris, France Posts: 350	Sony TV5-303M / 1963 5" B&W TV Good day Gentlemen, I have a little 5" Sony TV5-303M, this is the French & Euro version with 819 and 625 line standard. My local radio/TV repair shop has diagnosed it with a partial short circuit in the EHT transformer. Failure symptom: The TV5-303M can work fine for some time, then suddenly the picture shrinks horizontally & vertically with about a inch missing left & right, top & bottom. The TV has been partially recapped (power supply section) and when this happens the 12V supply remains stable.When the shrinkage happens, the H out transistor gets really hot because of excessive power drain. To repair it, I can either find the complete EHT assembly, Sony P/N1-353-001-02 (keep dreaming !) or buy a donor set with a healthy EHT transformer, for instance one which shows just a bright horizontal line across the screen. Now these sets show up frequently on E-Bay US but I don't know if a US EHT assembly will work on my French set. The US line frequency is 15750 Hz and ours at 625 is 15625 Hz, so no problem there. However I also use this set to demo 819 lines with the Aurora standards converter, and the H frequency at 819 is 20475 Hz. Knowing this, do you think I can substitute a US EHT transformer or will it overheat at 20475 Hz ? Of course if I had access to the Sony manual for the TV5-303W i.e. the US version, I could check the P/N and see if it is the same. Many Thanks! in advance for your advice, Best Regards Last edited by Mike Phelan; 31st Jul 2007 at 4:57 pm. Reason: Unusual word wrap!

19th Feb 2006, 11:16 pm	#2
Danny Heptode Join Date: Jul 2003 Location: North Walsham, Norfolk, UK. Posts: 516	Re: Sony TV5-303M / 1963 5" B&W TV Hi I would guess Sony used the same tranny and you wouldn't have a problem with the US tranny as the timebase is probably configured for this frequency. The EHT would be higher at this line speed though, I reckon they have altered the timebase to cater for this. I wonder if they used the LOPT from a more common model ? Is it an encapsulated unit or could the overwind be changed? Is it the same type as the 9" Sony dual or is it a more miniature type?. Danny

20th Feb 2006, 9:56 am	#4
oldeurope Retired Dormant Member Join Date: Dec 2003 Location: Solingen, Germany Posts: 727	Re: Sony TV5-303M / 1963 5" B&W TV Hi Jhalphen, please measure out the AC component at the pins of the EHT transformer. Voltage and polarity of the H- pulse. This makes it easyer to rewind it if neccessary. Kind regards Darius

20th Feb 2006, 11:34 am	#5
jhalphen Hexode Join Date: Jul 2004 Location: Paris, France Posts: 350	Re: Sony TV5-303M / 1963 5" B&W TV Hello Gentlemen, Many Thanks! for your numerous replies. To Danny : The EHT transformer is a highly miniaturized model. I will try to include pictures of the manual + the schematic. If this first attempt fails, I will have to make reduced versions of my scans. The EHT is hermetically sealed and the Sony manual specifically advises not to open it. My repair shop found that 2 of the closing tabs were partially open, probably the result of the sealing compound expanding because of excessive internal heat. To Fernseh: Hello David, I am very grateful and extremely interested in your planned test of running a TV9-90UB at 819 lines. This TV was indeed sold in France under the reference TV9-90UM. Alas, in my 3000 B&W TV pictures in my library I cannot find a single one of this model ;-( To Darius: As this is my first contact with you please let me say that I am honoured that the great developer of so many innovative transcoding/modulating devices is taking an interest in my little problem. Unfortunately Ii cannot answer your question as I left the Sony at the repair shop waiting for a donor EHT transformer. Best Regards to all, Jerome H Attached Thumbnails

20th Feb 2006, 12:46 pm	#6
oldeurope Retired Dormant Member Join Date: Dec 2003 Location: Solingen, Germany Posts: 727	Re: Sony TV5-303M / 1963 5" B&W TV https://www.vintage-radio.net/forum/...ead.php?t=6768 look at #3 for the pics of the SONY 625/819. Hi Jhalphen, attached a link to some pics of my Sony. Your EHT transformer looks like the one used in my camera viewfinder. There are valves in the schematic but, in real live not. You wrote: "My repair shop found that 2 of the closing tabs were partially open..." The interesting question is which tap must be opened to run the transistor hot? Maybe the Damper Diode goes o/c? Kind regards Darius Last edited by oldeurope; 20th Feb 2006 at 12:52 pm.

20th Feb 2006, 12:32 am	#3
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: Sony TV5-303M / 1963 5" B&W TV Hello Jerome, I've got a working TV9-90UB. Tomorrow, I could try supplying it with a 819 line UHF signal and after fiddling with the line frequency see what happens. I believe a 625/819 version of the TV9 was marketed in France. Regards, David.

20th Feb 2006, 2:33 pm	#7
jhalphen Hexode Join Date: Jul 2004 Location: Paris, France Posts: 350	Re: Sony TV5-303M / 1963 5" B&W TV Hello Darius, Thanks for the reply & for the link to your Sony CVM-90UM. Interestingly, the seemingly physically identical set sold in France was model TV9-90UM. I have a photocopy of the complete Sony service manual (40 pages). Reception is: VHF, French F2, F4-F12 CCIR Western Europen : Belgian E2-E12 Italian B(E-4) D(E-5) H(E-10) UHF, CCIR & French 21-69 Also the power supply is 110V/130V/220V. To come back to the TV5-303M, maybe i didn't express myself correctly: "My repair shop found that 2 of the closing tabs were partially open..." By writing this I meant that the closed EHT "tin can" started to open itself from internal pressure. The metal tabs were pushed open, I did not mean that taps on the transformer windings were open. You wrote: "The interesting question is which tap must be opened to run the transistor hot? Er, sorry I don't understand. Could a bad damper diode produce excessive heating of the H out transistor and a picture size reduction in all 4 dimensions ? The shop said "partially shorted turns on the EHT transformer, get a new one". Do you think I should take the set back and change the damper diode before trying to chase a complete EHT assembly. Should I get some 1DK1 rectifiers or can a solid state diode be substituted? If you could give me a reference (1N... or BY...) that would be a great help. Before Ii go on any further I must say that i have had excellent service from this shop for several years and I respect their knowledge. This is a father/son operation and the father, in his 60s, has great experience of vintage electronics. Thanks again for your help, Best Regards Jerome H

20th Feb 2006, 3:58 pm	#9
jhalphen Hexode Join Date: Jul 2004 Location: Paris, France Posts: 350	Re: Sony TV5-303M / 1963 5" B&W TV Hello Darius, Thanks for the reply. Since a very long time i've had much respect for Sony's innovative electronics, so even when i didn't have the money to buy their products when new, i would get a copy of the schematics just to see how they worked. I didn't know that 30-40 years in the future with the magic of low cost standards converters and low power transmitters i would be able to operate TVs of foreign standards (US & CCIR) right here in Paris. TV5-303M : I did not open the HV "tin can" so i'm not sure of the 1DK1's presence. However this is a 1963 product and when i repaired one in 1975 it did have the 3 tube rectifiers. To tell the story, from time to time i would hear arcing sounds. I inspected the TV in the dark to see sparks & saw none. Out of despair i opened the sealed EHT block. There was a blob of solder on one of the 1DK1s and when the humidity/temperature conditions were right, there would be a discharge between the tube's electrodes and the drop of solder. I removed the solder, filed the sharp points to a nice round shape, and the problem was solved. I don't have this TV anymore. The one causing problems was purchased from E-Bay Germany last year. I purchased it as it had the very hard to find VUC-4U UHF converter. I try to make all my TVs work at least once per month to keep the electrolytics in good shape. Best Regards Jerome H

20th Feb 2006, 7:13 pm	#10
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Sony TV5-303M / 1963 5" B&W TV Hello, Just a thought. I wondered if the original line output transformer was in fact faulty. You did mention that it worked for a while and then the scan reduced. Sounds more like a leaking capacitor or diode fed from one of the windings. It would be very frustrating to go to all this trouble just to discover the original was ok all the time...I know..I have done it! Regards JOHN.

20th Feb 2006, 7:44 pm	#11
jhalphen Hexode Join Date: Jul 2004 Location: Paris, France Posts: 350	Re: Sony TV5-303M / 1963 5" B&W TV Hello John, Thanks! for your advice. Maybe time for me to retrieve the set from the shop, find some 1DK1s and 3 x 500 pF 6kV caps. From a quick look by a US friend into the Stateside version of the 5-303, the flyback transformer has a different P/N than mine. I purchased the tubes previously here : http://www.vacuumtubes.com 6KV caps ? RadioSpares ? Mouser ? got a got Euro source perhaps ? Thanks for your help Best Regards Jerome H