Sl-7 Disassembly Problem

by **fscl** » 27 Dec 2009 14:25

LPFan advises:

Regarding attracting the opposite sex, it will be compulsary attraction then

Isn't that the best kind?

Guaranteed?

Women are so fickle anyway.....

Fred and professing not to see through women as fellow VE signature says because I would be missing a lot..... :oops:

by **xactifan** » 27 Dec 2009 15:46

[

xtifan,

Welcome to VE, I see it's your first post. Wow, SL-7 coming out of the woodwork to play again, like the Phoenix and the whole vinyl phenomenon....

Didn't want to leave you hanging, you can try cleaning the 3 LEDs under the platter first just in case, cotton swab w/ glass cleaner.

Refer to spikkie's picture and you will see the Optical Sensor pcb. From the owner's manual, this is pcb that has the optical sensors that detect the light coming through the platter guide slits. You will see the plastic blinder hanging askew, that selectively shades the sensors and feeding the logic chip telling the tonearm to drop (if safe) and in the correct position. Clean the sensors on this pcb. Trace the connector from this board to the main mother? board and make sure the connector / contacts are clean.

Hopefully, this along w/ a new / renewed belt will get your SL-7 playing properly.

Work the switches as it seems exercising contacts work.

That's it for now, until I can review my service manual for more ideas.

Good luck.

Fred and your English is lots better than my French....

[/quote]

Thanks for your quick and friendly answer, I was afraid that Sl(7)eeping beauty stay asleep under chloroform (not secure ?) I have to reawaken contacts, yes, so recently I ordered contact cleaner "Deoxit"and I am waiting for...is it a good product or not ? I used also a teflon grease on the tonearm guide and gears
I can see the 3 leds lightning through the platter guide slits (cover up) perhaps it's not necessary to clean them ?
I'll report back here after I finish washing up and I'm working the switches , hopefully

by **ATHERMOS** » 27 Dec 2009 16:52

Hi xtifan,

If the advice given does not help its time to check the photodarlingtons, they are PH101 types made by NEC. Check them using an LED with 47 ohms resistor in series with PH101 using a 3V supply (2 No. 1.5 volt cells). On flashing light on PH101 the led should glow to indicate a healthy PH101.

Cheers and best compliments of the season.

by **xactifan** » 27 Dec 2009 18:12

hi athermos,
Thanks for your advice, I'll try this after cleaning,it would hard enough for me because I have no experience working with these components :idea:

, but if it necessary,with your help and more details
photodarlingtons =discs sensors ?
Best regards

by **ATHERMOS** » 28 Dec 2009 17:27

Hi xtifan,

Please refer to the link below and follow the instructions given on the website to download the datasheet for the said component.

Link

http://www.alldatasheet.com/datasheet-p ... PH101.html

Best regards and the best compliments of the season,

by **ATHERMOS** » 28 Dec 2009 17:41

Hi xtifan,

Forgot to remind you that all precautions with regard to handling of CMOS components inside the turntable must be adhered to,more so this being the winter season. Again you must be aware of the fact that the components are interconnected so merely touching the bare copper foil on the PCB might just spell damage ( the 4069 is a CMOS IC).

Best regards and the best compliments of the season,

by **Dave in Green** » 28 Dec 2009 19:12

In addition to cleaning the switches, I would also suggest cleaning the contacts of all connectors. My problem was finally solved when I cleaned a connector that was not making good contact.

As far as repairing the ears on the acrylic cover, I can see that this is a difficult problem. Even though some glue is very good, the ears are quite small, and my experience has been that it is not easy to make a strong bond even with the best glue when there is such a small contact area for the glue to hold.

One possibility would be to get a piece of clear acrylic of the same thickness as the cover, and cut pieces that are larger than the ears they replace. Then glue 2 small pieces of acrylic to the inside and outside of the corner of the cover where the ear has broken off, and glue a 3rd piece inside the first 2 like a sandwich.

The new ear will be 3 times as thick as the old ear, and overlapping the cover will give the glue more area to bond to. It might not be "pretty," but I think it might be strong enough to hold.

by **fscl** » 28 Dec 2009 19:42

ATHERMOS wrote:Hi xtifan,

Please refer to the link below and follow the instructions given on the website to download the datasheet for the said component.

Link

http://www.alldatasheet.com/datasheet-p ... PH101.html

Best regards and the best compliments of the season,

ATHERMOS,

Great link.

Thank you and season's greetings.

Fred

by **xactifan** » 29 Dec 2009 10:06

ATHERMOS,

Thank you for your link very useful for me and all VE fellows. I’ll be careful , I'll follow your advice.
A newbie in electronic (and language)!
Season’s greetings

by **xactifan** » 29 Dec 2009 16:55

Hi Athermos,
I looked for the 4069 on the manual and found this link:
http://www.alldatasheet.com/datasheet-p ... 69UBP.html
Careful on the road!

by **ATHERMOS** » 29 Dec 2009 17:59

I am honoured by your responses, xactifan,fscl, I have found that most of these components can be found in the US and elsewhere but be extra careful of cheap duplicates especially when somebody offers you a new component which is otherwise known to be obsolete.

This link makes good reading:

http://sound.westhost.com/counterfeit.htm

And for those of you interested in valves ,here are 2 useful links

http://lenardaudio.com/education/14_valve_amps.html

and

http://sound.westhost.com/valves/index.html

Cheers and the best compliments of the season,

by **fscl** » 08 Jan 2010 22:55

flavio81 wrote:
fscl wrote: however I spied a bag of black, almost square cross section, a bit tighter / smaller OD RUBBER BANDS than the original belt. Of course at $0.99 I bought them and they WORKED.... no sound when driving. I mean I had thousands / hundreds of thousands..... so my SL-7 would live forever.....

You're THE HERO!! Can you measure the inner diameter (unstreched) please?

Finally got to taking and posting the picture..... :oops:

Fred

by **xactifan** » 19 Jan 2010 12:15

My SL-7 stay asleep...at least I cleaned all switches and contacts with
Deoxit. I've checked optical sensors with a Multimeter and found no
continuity but it's just the same with another SL-7 tested and working
well.
The Stop button don't respond,and with the Start button I can Start and
Stop pressing once more.
Sometimes the platter start turning when I push Power On.
"I'm really stumped on this one and would be grateful for advice from
anyone who has a working solution"!

Fred,I like your photo: bubbles champagne ? Cheers!
o

by **fscl** » 19 Jan 2010 13:56

xtifan writes:

The Stop button don't respond,and with the Start button I can Start and
Stop pressing once more.
Sometimes the platter start turning when I push Power On.

You're getting there..... try cycling the Start / Stop buttons....while the unit is off, they respond to repeated usage and eventually become "positive" (execute the desired function).

Did you clean and cycle the power switch?

Fred,I like your photo: bubbles champagne ? Cheers!

, No, like Frank, I still "get no kick from champagne"

This picture show the bag of rubber bands which served as a temporary repair / replacement for the tonearm drive belt. :shock:

which got displaced with a "real" O-ring drive belt sourced from a TV/VCR repair shop.

Fred and thinking your SL-7 is almost there to "fully working" status......