help identifying analog board

[falen5]

Hi folks.

Got an analog board to fix a 128K

Board looks to be in good condition but im not sure if it is 110 volt of 240 volt.

Most analog boards here in ireland are dual voltages ( well the ones ive seen ) but this one does not say what voltage it is

The only thing I see is the writing next to the fuse "Use rating 2.5 amp , 250 volt "

So is it safe to say this is a 240 volt analog board

 

[falen5]

just comparing it to the 110 volt I have , I think this is another 110 volt board - they both say the same at the fuse

surely it should be written somewhere on the board , what voltage it is

 

[cheesestraws]

Looks like a 110/120V board. 240V ones say INTERNATIONAL at the top and have four reservoir caps where that has two. (In theory, there are 120V INTERNATIONAL boards too and you have to look at one of the jumper wires to work out which, but I've never seen a non-240V INTERNATIONAL board personally)

 

[falen5]

Your right cheese straws.

Just looked at the other board I got for this , the damaged one that is dual voltages and it has 4 reservoir caps , just as you said.

So now I have a damaged 240 volt board , a decent looking 110 volt board , a 240 volt recap kit

ill plow ahead and recap the damaged board - see what happens

 

[cheesestraws]

ill plow ahead and recap the damaged board - see what happens

if I remember correctly, there's only one thing on those boards that's complete unobtainium so it's probably worth having a go.

 

[falen5]

not happy with the boards I got to fix this I went and took the analog board from my own machine

Just did a recap of the analog board using recap kit from console 5

it just starts this clicking

i have not changed all of the the small radial caps yet , theres about 5 to go

with logic board not connected I hear a distinctive clicking from the analog board , like some kind of relay clicking

i am getting a 'clicking' display so thats promising

is there a relay on there that powers everything up ?

 

[falen5]

heres a utube link

 

[bibilit]

Try replacing the Optoisolator, maybe your issue here.

 

[falen5]

Try replacing the Optoisolator, maybe your issue here.

Thanks for that bibilit - will check it first

I spent all of yesterday scouring this site and the net looking for possible fix's on this clicking. All I found was a reply on here from Elfen from 2014 and heres what he said " As for the ticking noise - try disconnecting the floppy drive before powering up, and see it the noise goes away. If not, I'm suspecting the usual suspects on the Analog Board - L1, R1, Q1, C1, Connector to the logic board and T1. Also like Uniserver said, their solder joints."

Thats all I found do far.

from what i was reading the optoisolator is the 6 pin chip next to the brightness control pot , U3 ?

 

[bibilit]

Yes U3

 

[falen5]

swapped it out U3 and its still the same - clicking

not getting anywhere here

thinking of going back to the original 128K 110 volt analog board and swapping out the flyback

I read its OK to take the flyback from from a mac plus analog board and swap it with the flyback of 128K analog board

the original 128K analog board is in better condition than the the mac plus board i have

 

[nathall]

FWIW, I get this on the original compacts if I forget to connect the wiring harness that goes to the logic board when I do poweup testing after servicing something. From your video it appears that harness is connected, so probably not your issue, but perhaps a clue?

 

[falen5]

Happy to report the flyback transplant from the Plus analog board to the original 128k analog has worked.

Recapped original analog board

When i first powered it up I got smoke from Q3 ( horizontal sync i think) - Reply from earlier post on this warned that if the flyback goes then Q3 will be the first victim down the line.

Swapped Q3 from plus board

Tried again and machine gave good beep with a perfect display

When i removed the original 128K flyback I got a clear view of its condition. Cracking , bulging etc etc.

And Nathall you are correct. If you power up the 128K without the logic board connected you get a clicking from the analog board.

I read 4.9 volts of the 5 and 12.02 volts on the 12.

Some slight screen adjustments , stripped and cleaned the floppy , recapped the 3 radials on the logic board.

Delighted with the results


Again would not have been possible without the amazing help from the amazing people on here


Big thanks to you all yet again.