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Guest

Sun Aug 11, 2019 3:45 am   



As i said earlier its a vintage deck from the days when my kids were young and used to sing karaoke on it now they are all above 20 y old and they are happy to see it working again and as for stupid design it is stupid because they didnt consider enough strength for mounting inside and there is no spare parts neither service manuals from the companey it self (i find one posted in a forum very thanks to that persone )without his manual i wouldnt be able to reach to this result .
Anyhow its just for those who like to keep on with thier memories

John-Del
Guest

Sun Aug 11, 2019 4:45 pm   



On Saturday, August 10, 2019 at 9:49:53 PM UTC-4, adnanka...@gmail.com wrote:
Quote:
As i said earlier its a vintage deck from the days when my kids were young and used to sing karaoke on it now they are all above 20 y old and they are happy to see it working again and as for stupid design it is stupid because they didnt consider enough strength for mounting inside and there is no spare parts neither service manuals from the companey it self (i find one posted in a forum very thanks to that persone )without his manual i wouldnt be able to reach to this result .
Anyhow its just for those who like to keep on with thier memories


I get it, but whereas that Pioneer was probably and honest 50WPC, you would be lucky to get a couple of watts per channel before the low current 12V tape deck source sags out or even fails completely. You should add a 12V transformer or use a buck converter and grab the now unused B+ source to supply it.

You still won't get the same power output as it had but you can probably get up to half of what it had before it failed.


Guest

Sun Aug 11, 2019 7:45 pm   



Dear john
Regarding the 12v dc that i used is comming from the main huge power supply and its current output is more than what the new amp board need and i did try it for long time on the original 110w×2 8ohm speakers with no over heat on the new board same aswell with old amp althought the new board is very compact and not power monger it can run on 12v- 24v in general as iam not an electronic engineer just a hobbies it was a challenge for me to bring life again to this vintage machine .
Actualy this machine is made from 2 sets one for the amp and casset and radio and another set for the 50+1 cd player conneted to the main set by a ribbone cable and power cord and back again to the bad design both sets has a voltage selector 110-240v last time ayears ago the kids try to use it they change the voltage selector to 240v on main set and didnt notice that the cd set need to be changed at same the result was the cd power suply blown because there is no fuse there it was another challange to be fixed coase there is no info about that output voltage and there is no schematic diagrams for that set to know the output voltage of that power supply after hard time of searching for a replacement i couldn't find any then i decided to desolder the transformer from the board to try winding it i find there at the input section unusable pin not connected to any traces on the board i check out if its connected to other pins and there was there i felt tgere is a hope i connected it serial with 70watt 110v lamp to avoid further damage and the result is the deck works again on 110v then i disconnect the volt selector leaving it direct and i add a small stepdown volt transformer from 240to 110v (i used small 30watt traveller converter which fit inside the deck housing ) it was a real challange but thanx GOD i did it and i liked to share this experience with other people who face this prob with PIONEER products and they like to keep them functioning after many years.

Don Kuenz
Guest

Fri Oct 11, 2019 5:45 pm   



Michael Terrell <terrell.michael.a_at_gmail.com> wrote:
Quote:
On Friday, October 11, 2019 at 9:49:58 AM UTC-4, m...@uga.edu wrote:
Perhaps one economic factor is that, as the cost of other components has
fallen, people expect the electrolytic capacitors to be very cheap also.
The capacitors now stand out as the expensive components. And that's an
incentive to lower standards.

Some of them are approaching zero value. Older equipment was expected to last
10 years or more. A lot of today's junk is lucky to last a year or two. In that
respect, the costs are going up, not down. Lower grade caps are a very high
failure item. I had one C-band receiver on the bench a few years ago. It had
about 85 electrolytics, and every one was bad Most had no brand name, and some
weren't marked for temperature. It belonged to a bar, and they needed it right
away, so they paid a large bill to have it working the next day. I generally use
Panasonic and Rubicon for repairs and my projects, these days.


Near the turn of the century a Missouri man named Chris started
badcaps.net Chris' "master list" enumerates the capacitors that he
trusts:

https://www.badcaps.net/index.php?pageid=master_list

Chris also hosts a lively forum at https://www.badcaps.net/forum/
Although its more apropos to repair.

Thank you, 73,

--
Don Kuenz KB7RPU
There was a young lady named Bright Whose speed was far faster than light;
She set out one day In a relative way And returned on the previous night.


Guest

Sat Oct 19, 2019 6:45 pm   



On Wednesday, May 14, 2003 at 1:46:00 PM UTC-7, Mike Bates wrote:
Quote:
I obtained this camcorder, and the VCR works fine, altho it can use a new
belt and idler kit.

Here is the problem, when I put it in camera mode, there is no autofocus,
shutter movement, or any video from the camera. there are just noise lines
in the VF. the noise lines dissapear when I flip it in VCR mode.

I can hear a very faint off-pitch hiss in the camera section while in camera
mode.

Any Ideas? I have no schematic to trace anything down. sounds like the hiss
is comming from a DC-DC on the camera board.


--
Remove the NOSPAMS to reply by E-mail.
Accounts Whitelisted, ALL EMAILS TRASHED
UNLESS NOSPAM IS IN SUBJECT LINE!

Applies to Newsgroups only! I hate spam.


Hello Mike,

I have the same camcorder and I am having the same issue. Power on the camcorder and switch to cam mode and just noise lines no visible video. I took mine apart and was going to check the dc - dc converter per the below comments. Did you have any luck with yours?

Fox's Mercantile
Guest

Sat Oct 19, 2019 8:45 pm   



On 10/19/19 12:30 PM, hpoole2020_at_gmail.com wrote:
Quote:
On Wednesday, May 14, 2003 at 1:46:00 PM UTC-7, Mike Bates wrote:
I obtained this camcorder, and the VCR works fine, altho it can use a new
belt and idler kit.

Hello Mike,

I have the same camcorder and I am having the same issue. Power on the camcorder and switch to cam mode and just noise lines no visible video. I took mine apart and was going to check the dc - dc converter per the below comments. Did you have any luck with yours?


I get the feeling Mike got rid of it 5-6 years ago.


--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

Allodoxaphobia
Guest

Sun Oct 20, 2019 5:45 pm   



On Sat, 19 Oct 2019 14:03:13 -0500, Fox's Mercantile wrote:
Quote:
On 10/19/19 12:30 PM, hpoole2020_at_gmail.com wrote:
On Wednesday, May 14, 2003 at 1:46:00 PM UTC-7, Mike Bates wrote:
I obtained this camcorder, and the VCR works fine, altho it can use a new
belt and idler kit.

Hello Mike,

I have the same camcorder and I am having the same issue. Power on
the camcorder and switch to cam mode and just noise lines no visible
video. I took mine apart and was going to check the dc - dc converter
per the below comments. Did you have any luck with yours?

I get the feeling Mike got rid of it 5-6 years ago.


err... uhh... More like 16 years ago!

google groopers -- the folk that keep on giving.

Jonesy


Guest

Fri Dec 13, 2019 3:12 pm   



My blaupunk tv is coming on but no picture just has the blaupunk on screen

Adrian Caspersz
Guest

Sat Dec 14, 2019 8:55 am   



On 13/12/2019 13:12, alanbiggrif74_at_gmail.com wrote:
Quote:
My blaupunk tv is coming on but no picture just has the blaupunk on screen


Corrupt firmware or dodgy internal PSU making the CPU crash.

Is there a reset button on the back?

--
Adrian C


Guest

Fri Dec 20, 2019 1:19 am   



On Saturday, November 22, 1997 at 3:00:00 AM UTC-5, Randy B wrote:
Quote:
Greetings Group,

I picked up an Infrared Motion Detector from a Flea market for a
dollar. It's a Telko "S002M", it has what looks like a DTMF style keypad
on the front and a small earphone type jack on one side. I wasn't able
to get any kind of instructions with it.

Does anyone know how to set the code for this? Or how to get ahold of
this company? Any response would be appreciated.

Randy Bray
Corvallis, OR.


pfjw@aol.com
Guest

Fri Dec 20, 2019 3:03 pm   



https://docs.google.com/document/d/1Xnrfajl1y-7D6emHhZVxNWTHT6SiDXoOXxvbjRx0qVQ/edit

The internet is your friend. Use it wisely.

Peter Wieck
Melrose Park, PA

Fox's Mercantile
Guest

Fri Dec 20, 2019 5:19 pm   



On 12/19/19 5:19 PM, jrketchum.rk_at_gmail.com wrote:
Quote:
On Saturday, November 22, 1997 at 3:00:00 AM UTC-5, Randy B wrote:
Greetings Group,


The original posting is 22 years old.


--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com


Guest

Sun Jan 26, 2020 10:45 am   



Il giorno giovedì 21 maggio 2015 22:14:15 UTC+2, cosen...@gmail.com ha scritto:
Quote:
Il giorno martedì 12 maggio 2015 18:58:39 UTC+2, Chuck ha scritto:
On Fri, 8 May 2015 12:39:15 -0700 (PDT), cosen...@gmail.com wrote:

MA27B1

Don't know of one, but this is the substitute that Panasonic
recommends.

---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com

I ordered some MA2C029WA from ic-chips.com. We will see if it suits....
Quite pricey the expedition costs to Europe... not sure if it's worth but I'm sentimentally bound the my Technics. Probably a bad thing :D

I'l try with these you recommend if those I ordered turn to be a not suitable / bad replacement.

Best,
Marco


I now gained quite some more experience on the subject. I can confirm MA2C029WA are a suitable replacement for the MA27-A2. I tested that for years in "production" on my own Technics SU-V3 amp. Of course I can't guarantee about extreme conditions but it seems to me that the key function of "stabilization" is performed by the negative slope of the VF-Ta curve which would guarantee that, in the configuration in which the diodes are used, the lowering of VF with temperature increase will change the bias point of the circuit in a way that prevents thermal runaway.
The MA2C029 series offers a very wide range of forward voltages and it basically serves the case of "double diodes". I need to do more research if I had to replace the MA26 itself but I think the search for a replacement may be much easier for that one.

See this thread also: https://audiokarma.org/forums/index.php?threads/matsushita-diode-ma27a2-ma26-2.621043/

Also some other hard to find diodes in these amps are the OA90 diodes. I was able to find some NOS on ebay at very reasonable prices and I stocked them up. See below for the datasheet.

Some technics amplifiers, for example the SU-8088, use the dreaded SVDSTV4HG.
Since that is attached to the heatsink with its very long leads (needs to be thermally coupled to the final transistors) it happens that sometimes the leads break because of mechanical stress and the bias circuit doesn't like that basically causing some cascade breakdown of the final stage.
See this dicussion
https://audiokarma.org/forums/index.php?threads/dead-power-amp-in-technics-su-8088-interesting-story.498025/


and also the datasheets:
https://www.alldatasheet.com/datasheet-pdf/pdf/13904/PANASONIC/MA2B027.html
http://datasheet.octopart.com/MA26-Panasonic-datasheet-108588.pdf
https://www.alldatasheet.com/datasheet-pdf/pdf/13911/PANASONIC/MA2C029.html
https://pdf1.alldatasheet.com/datasheet-pdf/view/166122/ETC1/OA90.html (on the third page!)


Guest

Sat Apr 18, 2020 10:45 pm   



My Panasonic nn sf464m has started to do this too. It's only a year old, did anyone find a fix?

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