8mm Forum: GS1200 Total Shut Down

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Posted by Paul Adsett (Member # 25) on September 21, 2019, 11:04 AM:

Well my GS1200 Version 2, which is my main projector, has totally failed. No power, no motor or fan, just the amplifier light and front side light come on. As soon as I throw the power switch on, it blows one of the 3.5 amp fuses on the transformer panel.
No idea what caused this but I had been having problems with the rear take up not working and was trouble shooting in the area of the big Matsushita relay on the control board. I found that if I gave that relay a tap then the rear take up would rotate for several minutes before quitting. I repeated this several times and then decided to reheat all the solder points that connect that relay to the control board, thinking it may have been a cold solder joint problem. It was after doing this that the projector refused to run at all, and I found out that it was blowing one of the main fuses on the transformer board.
Help! Any sugestions appreciated.

Posted by Leon Norris (Member # 3151) on September 21, 2019, 11:55 AM:

Paul, I'll give you a call!

Posted by Paul Adsett (Member # 25) on September 21, 2019, 12:04 PM:

Thank's Leon. I want to get this beautiful machine up and running again!

Posted by Steve Klare (Member # 12) on September 21, 2019, 12:16 PM:

Hi Paul,

I think you’ve bridged adjacent pins with solder.

(Happens to the best of us!)

Posted by Paul Adsett (Member # 25) on September 21, 2019, 03:15 PM:

Already checked that Steve, I see nothing like that.

Posted by Stuart Finkelstein (Member # 2380) on October 01, 2019, 03:58 AM:

I've had this happen before. It's usually a governor board or the ESS assembly. Both can be repaired. Don't lose hope.

Posted by Paul Adsett (Member # 25) on October 02, 2019, 03:14 PM:

Before starting any replacement of components on the big control board I did the following:

1. I removed the small motor board which plugs into the control board.

2. I switched on the power and the fuse did not blow, and the main blower motor now powers up and the lamp lights up in preheat mode.

Does this mean that the motor board is the problem ? Can it be repaired?

Posted by Phil Murat (Member # 5148) on October 03, 2019, 02:01 AM:

Hi Paul,

Very High probability you found out "issue root" [Wink] :

Upon some research in forums backgrounds from my side (German Forums too) some GS1200 owners have reported this typical problem (35V fuse burnt due to failed "Governor").
Often time , when "Governor" board fails, it generates a short-circuit on 35V power supply.
I/C UPC1002C fitted on "Governor" Board is probably out of order due to poor caps around.
Also it can be an aging failure which shows up for machines which have accumulated many working hours.

UPC1002C is an I/C "NEC" component, a bit difficult to get , but still available (minimum price around 5Eur in China) .

In case "Governor" refurbishment option is choosen :
A) To remove UPC1002C, it can be more confortable to cut pins before and to desolder each pin by each one in order to limit stress of board.
B) Install 14 pins DIL socket on board first then simply clips "firmly" new I/C on socket.(This minor modification allows fast futire installation/removal of I/C).
Pay particular attention during socket and I/C : Do not reverse position
C) Suggest to replace all caps and small transistors as an corrective action package.

Here is suggested 14 pins socket :

[ October 03, 2019, 05:54 AM: Message edited by: Phil Murat ]

Posted by Thomas Knappstein (Member # 6134) on October 05, 2019, 06:48 AM:

Hi Paul!
Are you on Facebook?
There is a Comunity for repairing this Stuff.

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