Sl-7 Disassembly Problem

[ATHERMOS]

Hello there,


I believe the broken solder joint is somewhere between IC 1&2's (78xx's) input and the (raw) low voltage AC supply coming to the main PCB. Always work on this PCB with a grounded iron.



Cheers !

[xactifan]

Hello Athermos,
Unfortunately I did not find the broken soldering joint, now the values fluctuates around 2-3mv with no peaks. To test further I've no experience to measure the values ,I don't know exactly where take them.
I should expect more learning about this and be careful I think and I regret not knowing follow this good advice.

cheers!

[ATHERMOS]

Check the incoming AC (low voltage) , which is coming from the transformer onto the PCB. Also check all the fuses.


Cheers !

[xactifan]

Thanks to good advice Athermos I do not abandon the party ! Now I have to replace IC1 and IC2 which the pins are broken. ,they are manufactured by NEC but obsoletes: SVIUPC7812H and SVIUPC78M05H. I searched with Google but without success There are many 7812 and 78M05 without H, but I'm too ignorant to find the exact equivalent. Other problem, sales are not for individuals but for companies and sending to France is often impossible. Here I am! I will be happy if someone can give me information on what or where to buy this...

[ATHERMOS]

Hello,

Nice to hear from you again. Please try 7812 and 7805 as substitutes and see whether the ICs can withstand the peak power dissipation, use heatsinks (and heatsink compound) if necessary

Regards,

[fscl]

DiGreen writes:

If I understood this problem better, maybe I could come up with an idea. Is it just the small "ears" on the clear plastic cover that break off, or is there more to it than that?

That's it 2 tiny ears.

I was thinking of putting metal corners in on both sides with the ear shape, but then I thought of the plastic latch on the bottom and after use, the plastic catch would eventually let go.

My thinking is to "JB Weld" / fill in that area, take a tracing of the intact one and then try milling out the bad side in the same shape with a Dremel

However, the last time I tried a Dremel to buff out some deep scratches on a dust cover, I ended up melting it....

I'm going to have to make a lump of JB Weld and then practice on shaping it......

Fred and that's the best I can come up with.....at this time

Just for fun, I poked around the Partstore website again today.....

Was curious to see what parts were available for the newly fleabay acquired SL 10. For some reason, this model was not in Partstore so I then entered the entire compact footprint Technics linearage

When I put in the SL 7, the "dustcover" part is once again listed and "available" so I purchased this (price is the same as last time) along with belts which show as an "available part" under the SL 5.

The dustcover is also listed as being used for an SL 6000? too. Is this tt the same as the SL 7 sold under the Panasonic brand? I pulled the trigger based on the cartridge replacement part the "TM-14".

Anyway, we'll see what happens / what I get.

Edit: I've been notified that the dustcover is going to ship at the end of
Feb.

Fred and looking at my lump of kneaded and hardened charcoal gray Quick Steel and going to attack with my Dremel tool for ear shaping for dustcover repair...... along with receiving a "new" one....

[fscl]

Update:

No dustcover, no replacement belts from Technics / Panasonics / Matshusta.

The Dremel broke down but was serviced and fixed.

Experimented with my lump of a 2 part putty when kneaded together formed a lump as hard as a rock with a mini router like tip and it looks like I can fill in the cover area and route out a latch.

Fred

[Dave in Green]

Congratulations, Fred! I've been away for awhile, but wanted to check back in to see how the SL-7 repairs were going. Mine has been humming along just fine since you and others here helped me get it going again.

[xactifan]

Repair of my SL-7: latest news!
After having changed the Regulators IC1 andIC2 the Power is back but the tone arm (and me!) are still blocked. It does not advance, like before.

I'm looking for the old service manual not the SL-7 manual "Revise" found in V.E.
My SL7 PCB is a bit different, especially the area of the arm motor drive
If anyone?...

[mscili]

Just a line to say thanks for such a great amount of useful information! Yesterday night I got a non-working SL-7, now I have a perfectly working one!

Bests,
Marco

[fscl]

Just a line to say thanks for such a great amount of useful information! Yesterday night I got a non-working SL-7, now I have a perfectly working one!

Bests,
Marco

CONGRATS and Welcome too......



How do you like the sound? and what cartridge is installed?

Fred

[topdevil]

As some of you have posted, I just recently got my old SL-7 out of storage and connected it to my receiver. It was a joy to listen to vinyl again but after a few plays, the arm began sticking, making the music skip as if the disc was badly scratched. It has become apparent that the tone arm is dragging in places. It will play fine a for a short time and then begin sticking. I can hit the stop button and the cartridge comes up and literally slides backwards a short distance. Sometimes the arm will return all the way back to the right, others it stops just short and you can hear the mechanism continuing to try to move the arm. Is this possibly a lubrication issue? The unit has been unused for going on twenty years. Any help from any one will be appreciated.

[chris@panteg]

I would say either the drive belt for the arm is slipping , or the grease on the the gear wheel has hardened up , take the cover off and take a look.

You can get a new belt from LPgear i believe , try cleaning off the old grease and relube , clean the slide bearing too with cotton buds and isopropanol .

[fscl]

In an effort to keep servicing information on Technics Linears here:

http://www.vinylengine.com/phpBB2/viewt ... c&start=15

See rolls-royce post for acceptable replacement belt.

Good luck.

Fred