This is topic sankyo 700 in forum 8mm Forum at 8mm Forum.
To visit this topic, use this URL:
https://8mmforum.film-tech.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=007919
Posted by Barry Webb (Member # 1897) on February 13, 2013, 01:53 PM:
Hi all I have got hold of a very nice sankyo 700 projector the lamp and amp are working but there is no power to the motor in forward or backwards when switching I have tested the motor and that seems fine any help would be great.
Barry.
Posted by Michael Wright (Member # 1387) on February 16, 2013, 03:20 AM:
Hi Barry, these are usually very reliable projectors, have you checked the fuses. Regeards MIKE
Posted by Maurice Leakey (Member # 916) on February 16, 2013, 04:46 AM:
The Sankyo main rotary knob controls micro switches, these often fail after years of use.
Posted by Barry Webb (Member # 1897) on February 20, 2013, 02:50 PM:
Thanks for all your help but I have tested the micro switches and there all fine, I have found a broken track on the main board and when I bridge it the board blows a fuse so I need a wiring diagram for it as I say the motor and transformer are fine but no power to the motor, lamp and amp work fine.
Barry
Posted by Steve Klare (Member # 12) on February 20, 2013, 03:13 PM:
The odds of finding a schematic aren't great, hopefully someone here has it and would share it. Personally I don’t, but I would share it if I did.
My wildest guess is there is some semiconductor (maybe motor speed control) device on that board that has shorted. The track that is blowing has become a fuse. What I would do is find that track and try to trace where it goes on the other side of the blast zone from the power supply connection. If you're lucky it goes to a few devices, if you are extremely lucky only one.
If you have several devices on that line, the thing is to try to unsolder the connections to that track one at a time and try to isolate the leg of the device from the board. When you find the right one, the short will clear. An ohmmeter is handy here: it's a lot less power and violence than the projector's power supply.
From that point its' a matter of identifying the dead part and finding a replacement. This many years down the road there’s no guarantee, but it’s worth trying.
The other possibility (which would be my first choice) is some sort of conductive debris has lodged in there and formed a short. With this violent a short there may be scorch marks around it.
Visit www.film-tech.com for free equipment manual downloads. Copyright 2003-2019 Film-Tech Cinema Systems LLC
UBB.classicTM
6.3.1.2