Author Topic: Yo100 help please  (Read 444 times)

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Offline Graham361

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Yo100 help please
« on: March 28, 2017, 12:10:18 PM »
Hi hope somebody can help I bought a yaesu monitor scope yl100 mains lead was missing so opened up today and looks like transformer has been replaced and unfinished as I now have two connector blocks the largest has wires from crt and the small one has two orange and white cables in I think this was done as transformer does not supply the these voltages I may be wrong were do I start any advice please regards graham

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Re: Yo100 help please
« Reply #1 on: March 28, 2017, 07:30:29 PM »
Hi Graham. I will pull the schematic tomorrow and look it over . Should be fairly easy to wire it back up.  Although I will say that most of the time something takes out the transformer. I would start checking all the caps on the secondary side of it.
Buddy kc4umo

Offline Graham361

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Re: Yo100 help please
« Reply #2 on: March 29, 2017, 05:52:26 AM »
Many thanks for your help can you tell me the two orange and white wires that originally went on old transformer what voltage are these I know the three blue are 6.3 volt I think the orange and white are 30volt I might be wrong and you were right two cappacitors are gone 600v ones I would say someone could not get a transformer with right voltages so have done this so they need a seperate supply as they fitted two power sockets at back off unit to supply 6.3volt for crt and what ever the orange and white feed is regards graham

Offline Graham361

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Re: Yo100 help please
« Reply #3 on: March 29, 2017, 11:43:36 AM »
This is what it's like the other side of the board mains lead cut and block added also one side of switch cut

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Re: Yo100 help please
« Reply #4 on: March 30, 2017, 06:11:15 PM »
Thanks for those pictures. That helps. I have been extremely busy the past two days. I am off tomorrow and will see if I can get into the schematic for you.
Buddy kc4umo

Offline Graham361

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Re: Yo100 help please
« Reply #5 on: March 31, 2017, 04:09:42 AM »
Many thanks regards graham

Offline Graham361

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Re: Yo100 help please
« Reply #6 on: April 01, 2017, 04:10:40 PM »
Also found two brown wires under crt I think these also went on transformer so the two sets I am not sure of voltages they need is the two orange and white and the two brown regards graham

Offline Graham361

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Re: Yo100 help please
« Reply #7 on: April 03, 2017, 02:09:16 PM »
The two orange and white cables go to rectifier board from transformer

Offline Graham361

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Re: Yo100 help please
« Reply #8 on: April 05, 2017, 04:08:15 PM »
Three of the 5 capacitors were dead so changed all five these were on the rectifier board they look like they got really hot would this have caused the transformer to go u/s in the first place regards graham

Offline Graham361

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Re: Yo100 help please
« Reply #9 on: April 05, 2017, 04:11:31 PM »
These are the six I replaced

Offline Graham361

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Re: Yo100 help please
« Reply #10 on: April 06, 2017, 03:33:30 PM »
Today with not much experience i wired up transformers and switched it on all valves light up and crt and to my surprise have a trace on screen the vertical and horizontal work and focus but some don't function as I still have two sets of wires the two brown and the two orange and white that I am not sure of voltages regards graham

Offline Graham361

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Re: Yo100 help please
« Reply #11 on: April 06, 2017, 03:35:09 PM »
View of board with valves and crt

Offline Graham361

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Re: Yo100 help please
« Reply #12 on: April 06, 2017, 03:36:34 PM »
Front view with trace

Offline Graham361

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Re: Yo100 help please
« Reply #13 on: April 06, 2017, 03:39:18 PM »
The main transformer and small transformer giving 6.3volts for crt and valve heaters