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Topic: OH NO another Beaulieu 708 stereo issue
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Phil Murat
Jedi Master Film Handler
Posts: 671
From: Villeneuve St Georges, France
Registered: Dec 2015
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posted December 08, 2018 05:12 AM
Hi Mark,
Have a look there :
BD646 : SUPPLIED BATCH
I have checked with UK destination, shipping is free!!!
May Ebay Too can supply but probably for higher money.
So.......
Do you confirm your machine is running "smoothly" at this time and main motor is regulating ??? Did you do this test : Run your machine on playing sound mode and push with your finger the black rocking guide (from outside to capstan direction). If you can ear main motor idling , that means main motor is regulating.
In that case power of immediatly the machine, and unplugged it, as it is possible BD646 is not properly coolled :
Check BD646 installation and renew white cream (heating dissipation compound between BD646 lug and casing).
A common Heating Dissipation Compound is supplied by Dow Corning Cy.
THIS IS IMPORTANT TOO : BEFORE TO POWER ON MACHINE , MEASURE ELECTRICAL RESISTANCE BETWEEN CASING AND BD646 LUG WHICH HAS TO BE VERY VERY HIGH (May BE AROUND 45 MEGA HOMS !!)
FINAL RELEASING TEST :
To insure BD646 is NOT over heating put your finger on BD646 plastic case. if you can not stand Heat that means temp is too high. (From my side I use an Infra Red Thermometer)
Let us know [ December 08, 2018, 07:42 AM: Message edited by: Phil Murat ]
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Phil Murat
Jedi Master Film Handler
Posts: 671
From: Villeneuve St Georges, France
Registered: Dec 2015
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posted December 08, 2018 07:23 AM
//////////////// Just Updated Informations /////////
Absolutly Mark.
Renew white Termal Dissipating compound, a thin homogeneous layer only (A thin layer on casing, apply micas shim, put an other layer on micas shim, then reinstall....) Use Vinyl Glothes to prevent from contact with skin.
Take the opportunity to put this layers for 3 regulators (IC1, IC2, IC3).
Yes, this is what I am thinking. After projector power off and coolled down, It can run properly. However BD646 is probably suffering and could fail later.
Pay particular attention for good fitting for lugs regulators on casing. Insure you a full surface contact between lugs and case. For BD646, insure you screw and plastic bushing are well centered in lug hole. However , do not over tighten screw, plastic bushing is fragile....
At this time , it is not necessary to replace BD646, however it should be a good thing for you to get some of this on left....
INFO: You can find thermal compound in shop specialised in maintenance computers. Only use a compound quality which NEVER dry.
Let us know
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Phil Murat
Jedi Master Film Handler
Posts: 671
From: Villeneuve St Georges, France
Registered: Dec 2015
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posted December 09, 2018 03:30 AM
Hello Mark,
During a "sleeping night" something comes to my mind concerning a possible intermitent speed issue ......
In case BD646 is working properly, not overheating, and offering an obvious dual range (18fps/24fps) :
-Considering the black "rocking sensor" has an obvious effect when projector is playing sound ,I suggest you to check efficiency for pinch roller. Machine power OFF, insert a portion of film leader between Capstan shaft and Pinch Roller, Turn main knob on Sound Mode and gently pull the leader portion outboard..... You should observe Capstan shaft and Pinch roller spinning together. If Leader slides too much "easily" and Capstan Shaft / Pinch Roller don't spin properly , means something is wrong with internal linkage from from cams axis to Pinch Roller carrier. In that case check linkage inside projector for an excessive play, jams part, soften spring, foreign material blockage , etc , etc.... This is a rare condition, but.......... To tell you the truth I met a funny smilar fault, one time. I sprayed thin oil (liquid lithium grease or equivalent) and everything was ok after all.
To gain access to linkage, remove Capstan Motor then Flywheel (record washers/bushings position).
Let us know
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