Sony SL-C9 Betamax DC-DC converter - UK Vintage Radio Repair and Restoration Discussion Forum

Snarf81 · 12th Dec 2019, 6:03 pm

Hi everyone,
The saga of trying to get my vcrs in full working order is reaching its climax!!

I need a working DC-DC converter for my C9. Mine is defective which results in no clock display and the tuner not storing channels (obviously that side of things isn't needed anymore). I don't have the appropriate tools to open the metal cans on mine as they're soldered together and need a considerable amount of heat to open it.
There's a seller on that online auction site selling a newly designed version for nearly £100...! I love my C9, but not that much!

If anyone has a working DC-DC converter for sale please let me know.

Thanks in advance
Richard.

greg_simons · 12th Dec 2019, 7:23 pm

Pure unobtainium, the best thing to do is repair it or get someone to repair it for you, 100 smackers is really taking the #$@, even back late in the day we had to fix them when they became NLA.
Greg.

Snarf81 · 12th Dec 2019, 7:32 pm

Oh blimey. That's not good news. Hmmmm. I'm going to have to think of a way to get the darn thing open then.

stevehertz · 12th Dec 2019, 8:43 pm

They are as rare as rocking horse droppings, hen's teeth or unicorn horns. You have to unsolder and rebuild them. Easier said than done..

Take a look here: https://www.palsite.com/pcat_dcdc.html

greg_simons · 12th Dec 2019, 9:25 pm

Not too bad to repair and you don't need a mega watts soldering iron to get the lid off, just a little patience to break the seal. all round with some thin pry tools, providing you're ok with close packed circuitry you'll be ok.
Greg.

Goldieoldie · 12th Dec 2019, 11:42 pm

Could you use a new converter availible in a wide range of voltages ?
And cheap !
Cheers
Pete

Snarf81 · 12th Dec 2019, 11:51 pm

Hi Pete,
I've not looked into that, I wouldn't know really where to start.

Cheers
Richard.

Goldieoldie · 13th Dec 2019, 12:13 am

There are loads on EBay .
If you search DC - dc boost converter

whiskas · 13th Dec 2019, 12:53 pm

Hi Richard,
I fixed the DC-DC converter in my C9 recently, here are some pics of the job - and the end result. (last 2 photos)
It's tricky, but do-able - needs patience and a steady hand!
I did mine with a 25W antex iron (to open the can), solderwick to remove as much solder as possible, then prising the can open with a fine tip screw driver, a little at a time.
Don't rush it!
Probably you'll need to change the caps and transistor, and remove any glue that's gone 'dark'.

whiskas · 13th Dec 2019, 12:53 pm

oh I forgot to attach pics!

stevehertz · 13th Dec 2019, 1:18 pm

Quote:

Originally Posted by whiskas

oh I forgot to attach pics!

Nice job.

greg_simons · 13th Dec 2019, 1:29 pm

Quote:

Originally Posted by whiskas

oh I forgot to attach pics!

Nice work whiskers
Yes indeed, be sure to scrape as much of that brown glue away as possible, it goes conductive after a few years, your pictures illustrate perfectly how to open the tin.
Greg.

Snarf81 · 13th Dec 2019, 1:30 pm

Hi Rob,
Ah that's lovely, thank you for that info! I'll take a look online somewhere to see what caps and transistor I need to order to rebuild the damn thing.

Cheers
Richard.

whiskas · 13th Dec 2019, 1:38 pm

I should add that I recommend drilling some 4mm vent holes in the can (which was what they did in the later ones to assist with cooling, making it more reliable.)
Make sure you drill it exactly as Sony did it with the later version of the DC-DC converter - see attached photo.
Did I say be *gentle* with the PCB - watch out for solder bridges!
Basically I took the whole module to bits and rebuilt it. So long as your coils are OK you should be fine, but check every part as you can.
Be *very* careful removing any glue attched to the coils, if you damage the coils, you're knackered.
And use solderwick, of course... and lots of patience...

af024 · 13th Dec 2019, 7:02 pm

There's also this old thread which may help ...
https://www.vintage-radio.net/forum/...ad.php?t=95103

Regards,

Andy

Snarf81 · 13th Dec 2019, 8:00 pm

That's great information. Thank you, Andy!!

toshiba tony · 14th Dec 2019, 1:34 am

Hello, they weren't that bad, did them on site but £100 is taking the mick. I'm sorry but I laughed at the price, but it is the weekend and I have had a slurp, as has been said, a transistor and the caps for good measure.

af024 · 14th Dec 2019, 9:20 am

You are very welcome Snarf81. Oh, and I think pins 6 and 5 are shown the wrong way around on the drawing. Good game eh.

dj_fivos_sak · 14th Dec 2019, 2:45 pm

Hi Snarf81. Have you watched this video?
https://www.youtube.com/watch?v=_9CVPghyCcY

Regards,

Fivos

flyingtech55 · 14th Dec 2019, 6:45 pm

Failure of the dc-dc converter was very common on these machines. We didn't sell many of them but we saw most of those we did back at some time with the converter failed. I seem to remember that the bottom part of the Sony F1 portable outfit also contained the same, or similar, converter. It wasn't a cheap part either and the customers weren't too happy about it. The converters became unobtainium relatively soon after the machines went out of production. The converters were never meant to be repaired. They were supposed to be treated like any other failed component and renewed accordingly. I was never very impressed with the later Sony stuff....too complex, full of fragile plastic parts, lots of leaky surface mount electrolytic capacitors and very expensive parts prices. The parts took too long to arrive too even though we were an official Sony dealer.

Wasn't sorry to see the back of them.

TimR

12th Dec 2019, 6:03 pm	#1
Snarf81 Heptode Join Date: Aug 2018 Location: Rogiet, Monmouthshire, Wales, UK. Posts: 615	Sony SL-C9 Betamax DC-DC converter Hi everyone, The saga of trying to get my vcrs in full working order is reaching its climax!! I need a working DC-DC converter for my C9. Mine is defective which results in no clock display and the tuner not storing channels (obviously that side of things isn't needed anymore). I don't have the appropriate tools to open the metal cans on mine as they're soldered together and need a considerable amount of heat to open it. There's a seller on that online auction site selling a newly designed version for nearly £100...! I love my C9, but not that much! If anyone has a working DC-DC converter for sale please let me know. Thanks in advance Richard.

12th Dec 2019, 7:23 pm	#2
greg_simons Octode Join Date: Jul 2004 Location: Evesham, Worcestershire, UK. Posts: 1,422	Re: Sony SL-C9 Betamax DC-DC converter needed. Pure unobtainium, the best thing to do is repair it or get someone to repair it for you, 100 smackers is really taking the #$@, even back late in the day we had to fix them when they became NLA. Greg. __________________ Picture, sound?, DOOR.

12th Dec 2019, 7:32 pm	#3
Snarf81 Heptode Join Date: Aug 2018 Location: Rogiet, Monmouthshire, Wales, UK. Posts: 615	Re: Sony SL-C9 Betamax DC-DC converter needed. Oh blimey. That's not good news. Hmmmm. I'm going to have to think of a way to get the darn thing open then.

12th Dec 2019, 8:43 pm	#4
stevehertz Dekatron Join Date: Sep 2011 Location: Rugeley, Staffordshire, UK. Posts: 8,831	Re: Sony SL-C9 Betamax DC-DC converter needed. They are as rare as rocking horse droppings, hen's teeth or unicorn horns. You have to unsolder and rebuild them. Easier said than done.. Take a look here: https://www.palsite.com/pcat_dcdc.html __________________ A digital radio is the latest thing, but a vintage wireless is forever..

12th Dec 2019, 9:25 pm	#5
greg_simons Octode Join Date: Jul 2004 Location: Evesham, Worcestershire, UK. Posts: 1,422	Re: Sony SL-C9 Betamax DC-DC converter needed. Not too bad to repair and you don't need a mega watts soldering iron to get the lid off, just a little patience to break the seal. all round with some thin pry tools, providing you're ok with close packed circuitry you'll be ok. Greg. __________________ Picture, sound?, DOOR.

12th Dec 2019, 11:42 pm	#6
Goldieoldie Octode Join Date: Jul 2014 Location: Petersfield, Hampshire, UK. Posts: 1,043	Re: Sony SL-C9 Betamax DC-DC converter needed. Could you use a new converter availible in a wide range of voltages ? And cheap ! Cheers Pete

12th Dec 2019, 11:51 pm	#7
Snarf81 Heptode Join Date: Aug 2018 Location: Rogiet, Monmouthshire, Wales, UK. Posts: 615	Re: Sony SL-C9 Betamax DC-DC converter needed. Hi Pete, I've not looked into that, I wouldn't know really where to start. Cheers Richard.

13th Dec 2019, 12:13 am	#8
Goldieoldie Octode Join Date: Jul 2014 Location: Petersfield, Hampshire, UK. Posts: 1,043	Re: Sony SL-C9 Betamax DC-DC converter needed. There are loads on EBay . If you search DC - dc boost converter

13th Dec 2019, 12:53 pm	#9
whiskas Octode Join Date: Mar 2016 Location: Knutsford, Cheshire, UK. Posts: 1,495	Re: Sony SL-C9 Betamax DC-DC converter needed. Hi Richard, I fixed the DC-DC converter in my C9 recently, here are some pics of the job - and the end result. (last 2 photos) It's tricky, but do-able - needs patience and a steady hand! I did mine with a 25W antex iron (to open the can), solderwick to remove as much solder as possible, then prising the can open with a fine tip screw driver, a little at a time. Don't rush it! Probably you'll need to change the caps and transistor, and remove any glue that's gone 'dark'. __________________ ...where on earth did that spring/screw go??

13th Dec 2019, 1:30 pm	#13
Snarf81 Heptode Join Date: Aug 2018 Location: Rogiet, Monmouthshire, Wales, UK. Posts: 615	Re: Sony SL-C9 Betamax DC-DC converter needed. Hi Rob, Ah that's lovely, thank you for that info! I'll take a look online somewhere to see what caps and transistor I need to order to rebuild the damn thing. Cheers Richard.

13th Dec 2019, 1:38 pm	#14
whiskas Octode Join Date: Mar 2016 Location: Knutsford, Cheshire, UK. Posts: 1,495	Re: Sony SL-C9 Betamax DC-DC converter needed. I should add that I recommend drilling some 4mm vent holes in the can (which was what they did in the later ones to assist with cooling, making it more reliable.) Make sure you drill it exactly as Sony did it with the later version of the DC-DC converter - see attached photo. Did I say be gentle with the PCB - watch out for solder bridges! Basically I took the whole module to bits and rebuilt it. So long as your coils are OK you should be fine, but check every part as you can. Be very careful removing any glue attched to the coils, if you damage the coils, you're knackered. And use solderwick, of course... and lots of patience... Attached Thumbnails __________________ ...where on earth did that spring/screw go??

13th Dec 2019, 7:02 pm	#15
af024 Octode Join Date: Jan 2003 Location: Ashby-de-la-Zouch (it's not by the sea) Posts: 1,255	Re: Sony SL-C9 Betamax DC-DC converter There's also this old thread which may help ... https://www.vintage-radio.net/forum/...ad.php?t=95103 Regards, Andy __________________ Now where on earth did I remove that from?

13th Dec 2019, 8:00 pm	#16
Snarf81 Heptode Join Date: Aug 2018 Location: Rogiet, Monmouthshire, Wales, UK. Posts: 615	Re: Sony SL-C9 Betamax DC-DC converter That's great information. Thank you, Andy!!

14th Dec 2019, 1:34 am	#17
toshiba tony Heptode Join Date: May 2006 Location: Accrington, Lancashire, UK. Posts: 978	Re: Sony SL-C9 Betamax DC-DC converter Hello, they weren't that bad, did them on site but £100 is taking the mick. I'm sorry but I laughed at the price, but it is the weekend and I have had a slurp, as has been said, a transistor and the caps for good measure.

14th Dec 2019, 9:20 am	#18
af024 Octode Join Date: Jan 2003 Location: Ashby-de-la-Zouch (it's not by the sea) Posts: 1,255	Re: Sony SL-C9 Betamax DC-DC converter You are very welcome Snarf81. Oh, and I think pins 6 and 5 are shown the wrong way around on the drawing. Good game eh. __________________ Now where on earth did I remove that from?

14th Dec 2019, 2:45 pm	#19
dj_fivos_sak Heptode Join Date: Mar 2015 Location: Lefkada, Greece Posts: 969	Re: Sony SL-C9 Betamax DC-DC converter Hi Snarf81. Have you watched this video? https://www.youtube.com/watch?v=_9CVPghyCcY Regards, Fivos

14th Dec 2019, 6:45 pm	#20
flyingtech55 Octode Join Date: Nov 2005 Location: Ayrshire, UK. Posts: 1,096	Re: Sony SL-C9 Betamax DC-DC converter Failure of the dc-dc converter was very common on these machines. We didn't sell many of them but we saw most of those we did back at some time with the converter failed. I seem to remember that the bottom part of the Sony F1 portable outfit also contained the same, or similar, converter. It wasn't a cheap part either and the customers weren't too happy about it. The converters became unobtainium relatively soon after the machines went out of production. The converters were never meant to be repaired. They were supposed to be treated like any other failed component and renewed accordingly. I was never very impressed with the later Sony stuff....too complex, full of fragile plastic parts, lots of leaky surface mount electrolytic capacitors and very expensive parts prices. The parts took too long to arrive too even though we were an official Sony dealer. Wasn't sorry to see the back of them. TimR __________________ All those moments will be lost in time, like tears in rain.