8mm Forum: Beauleiu 708 el stereo NO SOUND?????

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Posted by Mark L Barton (Member # 1512) on November 29, 2018, 03:25 PM:

Hello, my Beaulieu 708 el stereo is not playing sound. The speakers do not hum, the VU meters are not lit and even if I press the record button in , no lights. Projector projects fine, but absolutely no sound.
Could it be a fuse etc etc
Your goodly advice please. Thank you

Posted by Paul Browning (Member # 2715) on November 29, 2018, 05:56 PM:

Could be the amp fuse, but why it would take out the vu lamp lights is not clear to me. There is only one fuse on the back plate, no obvious separate fuse on out side of the projector for the amp that's marked up. Do you have a mic to check the amp is actually working separate to the sound head side ?.

Posted by Nantawat Kittiwarakul (Member # 6050) on November 29, 2018, 07:21 PM:

Maybe not the case but...

Recently bought this Ricoh Super8 projector dirt cheap (about 33$ include shipping) which was totally dead on arrival.

Turns out to be faulty capacitors that had to be replaced. For the amplifier section,under magnifier I found some cracked solders beneath amplifier's transistor pin. After re-soldering them it become alive again.

So it might worth having a good look at the whole board with a magnifier. [Razz]

Posted by Phil Murat (Member # 5148) on November 30, 2018, 12:53 AM:

Hello Mark,

A) I suggest you these electrical measures :

- If Voltage recorded is +32v instead of 24V (small tab below picture) , try to adjust with RA2 Trimmer. If no change is observed, means Voltage Regulator IC1 (L200C, 5 lugs) has failed out , or closed capacitor (green bloc) has failed as well.

If Voltage recorded is 0v instead of 24V, measure IC1 (L200C) incomming voltage from Diode D5 last pin : you should read +32V.

If voltage is very low and fuse is OK, means Diodes "train" D1 to D5 has to be reniewed.

Before to measure "24V" on the tab, disconnect the Red Lug from this tab ; just in case there is a 32V (No more regulated Voltage). A +32V could stress some Pre-Amp components .

L200C Power Regulator , Diodes, Caps are easy to find on the market for few money.

- You should find +42V on upper lug (Upper side of the picture).
This voltage is usually stable but not regulated. It supplies current for Amp Power section.

B) Are both fuses Ok ?

Let us know.

Hope this will be helpfull

Phil

[ November 30, 2018, 02:39 AM: Message edited by: Phil Murat ]

Posted by Mark L Barton (Member # 1512) on December 04, 2018, 02:05 PM:

Had a look inside the 708el stereo. There is a loose brown wire attached to the speaker wiring (yellow and black) bundle. It has a fitting that looks like it's detached from the circuit board, but l cannot see where. Does this make sense? Thank you

Posted by Phil Murat (Member # 5148) on December 05, 2018, 12:44 AM:

Hi Mark,
Yes, it does..... for 100%
Brown wire is the 24v power for pre-amp section .
The small lug soldered on board is broken , flush to the board, remaining portion of lug is still inside spade connector.
You need to replace the lug on the board.
This is a usual failure on Beaulieu 708, minor, fortunately .......
You need to remove the regulating board to perform the job.
The lug is fitted on the left corner of board, next to green capacitor.
You can see this lug on first picture (post above) , a red arrow +24v is pointing it.

Posted by Mark L Barton (Member # 1512) on December 05, 2018, 04:44 AM:

Hi Phil
Thank you for your kind reply.
So, if I reattach this wire it should work? I have attached a picture, is this where the lug should go (red arrow) Im not sure what part of the capacitor I should attach the lug to. Could you help further please, or a drawing?? Thank you so much for your help, greatly appreciated. Mark

Posted by Phil Murat (Member # 5148) on December 05, 2018, 05:48 AM:

Hi Mark,

Absolutely , see through a close picture :

This kind of connector is unfortunately very fragile......

If you want to obtain configuration as origine , you need this kind of lug (2,8mm) :

An alternative solution is to solder a wire portion on board with this kind of male connector :

Alternative solution is my prefered because when you need to disconnect the spade connector from the pin , there is no stress on the solder on the board.

Do you have necessary tools to make the job ?

- A small soldering iron maxi 20w, "pencil tip"
- Soldering wire , diam 1mm approx, electronic quality.
- A lengh portion of copper mesh, approx 10cm (used for remove former soldering material on board track on pin lug location)
- Heat-Shrinkable sleeve, tube (red colour)

Posted by Mark L Barton (Member # 1512) on December 05, 2018, 05:59 AM:

Thank you Phil.
Yes i have the tools, but am concerned as to where I solder the lug. Is it soldered to one of the capacitor 'legs' etc. Please advise. Kind regards mark

Posted by Phil Murat (Member # 5148) on December 05, 2018, 06:08 AM:

The 2,8mm lug connector is fitted in its own hole , close to the capacitor.

Hole is 0,8mm to 1mm approx diameter , so far I remember.

IMPORTANT NOTICE FOR BOARD REMOVAL/INSTALATION :

1)Observe Power regulator (in the midle) which is fitted to casing.
This regulator BD646 HAS TO BE PERFECTLY INSULATED FROM THE CASE.
The Regulator lug is installed on a micas sheet and a tiny plastic bushing on 3mm screw.
When re installing BD646 lug , check insulation with Ohmeter between BD646 lug and case , resistance has to be very very high !!!

Check final Electrical resistance between lugs and case once board installed and before to power on the machine

A poor insulation will result in BD646 immediate failure and will cause main motor no more regulated.

2) For installation of L200C power regulators , this is opposite to 1): Resistance between their lugs and case HAS TO BE VERY LOW (almost perfect continuity).
If this condition is not met you will experienced extra spurious noises when playing sound.
For L200C installation, no insulating bushing, no micas sheet below lug......

You can see the plastic bushing and micas sheet (Midle BD646 Regulator) on the picture , upper post...

Do not hesitate to ask for more info if there is something confused.

Let us know

Phil

Posted by Mark L Barton (Member # 1512) on December 05, 2018, 06:54 AM:

Thanks Phil, so basically I need to find the small hole near the capacitor, and solder the lug there, thats correct yes? Thank you Mark

Posted by Phil Murat (Member # 5148) on December 05, 2018, 07:03 AM:

This is correct Mark...........

To tell you the truth , I often use a magnifying glass (X3) now , when I work on Electronic systems

Posted by Oliver F. R. Feld (Member # 1911) on December 05, 2018, 07:13 AM:

Mark and Phil: You are absolutely amazing!
Fingers crossed that the Beaulieu will shine again!

Posted by Mark L Barton (Member # 1512) on December 05, 2018, 07:21 AM:

Will be attempting this after work tonight. Will post results.

Posted by Phil Murat (Member # 5148) on December 05, 2018, 08:10 AM:

No doubt this beautifull machine will be released to service before Christmas !! [Wink]

COMPLEMENTARY INFO :

Once board is reinstalled and wires connected, pay particular attention for proper routing for left harness. Manage and insure a confortable clearance between left Harness and Flyweel to prevent fretting between Flyweel and wires.

Posted by Mark L Barton (Member # 1512) on December 05, 2018, 04:07 PM:

SUCCESS!!!!!!!!!
Hi Phil, thanks to you I now have a Beaulieu 708el Stereo projector that is playing back sound. The brown blade I could see where it was attached, whilst doing the repair the black cable lug to the amp simply fell off (design fault, too much stress??) So, instead of finding lugs to solder into the circuit board, I used audio cable and attached the remainder of the lug to the cable, then reattached to the black and brown wires. This way there is slightly less stress on the solder etc etc. So Phil, thank you , Merci bien. PS I now need to find a new drive belt for the flywheel that goes to the little motor next to the audio circuit board, as its very loose and causing the projector to wow and flutter. Where would be the best place to get that belt?

Posted by Phil Murat (Member # 5148) on December 06, 2018, 07:14 AM:

Hi Mark,

It's a pleasure to share what I can !

You have achieved an excellent job [Wink]

Very glad your machine is back to life.

Beaulieu 708 is probably the easiest modern S8 projector to maintain (Not too much manhours to spent , even if , unfortunately , spares parts are too much expensive)

A good news is that alternative (and very good) solutions can be applied for low money.

I assume Van Eck has spare belts, however I have never replace one of them

Posted by Alessandro Pavoni (Member # 1739) on December 06, 2018, 09:10 AM:

Hi Mark, you can find a capstan belt here:

http://www.ffr-film.de/index.php?page=antriebsriemen&language=eng

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