SOLVED: G05 802 Deflection Board Issue

dochowl

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I have a G05 802 that is having the issue seen in the youtube video I posted below.

https://youtu.be/NrwWDeh1MIc

The issue is definitely on the deflection board as I've tested with a spare and that one works just fine. I have gone through and cleaned and reflowed all of the connectors, checked fuses, adjusted pots to no avail. I have not gone through the board in detail checking restistors, diodes, etc.

Any thoughts? I was thinking it might in fact be a bad linearity pot (or multiple), but I don't have spares to replace at this time.

Thanks for any direction.
 
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I have a G05 802 that is having the issue seen in the youtube video I posted below.

https://youtu.be/NrwWDeh1MIc

The issue is definitely on the deflection board as I've tested with a spare and that one works just fine. I have gone through and cleaned and reflowed all of the connectors, checked fuses, adjusted pots to no avail. I have not gone through the board in detail checking restistors, diodes, etc.

Any thoughts? I was thinking it might in fact be a bad linearity pot (or multiple), but I don't have spares to replace at this time.

Thanks for any direction.

if you need any pots i think i have most the vector chassis pots and most pots i put the PCB location in the description on our site so you can search by just the pcb location.
 
Interesting. Can't say I've seen that one before.

Since it appears to be affecting both the X and Y axes, I'd suspect a power supply issue first. Maybe check the filter caps, as well as the soldering of them, as the joints on those can crack easily, if the caps get whacked or pushed on too hard.
 
I wonder if there is something wrong with the z input q504.
There is something affecting both X and Y. Z input is common and so is the power section on the defection board.

Maybe it time to get the scope out and and do some comparison probing between the working and no working one?
 
I'd personally get a multi meter set to diode mode and test all the TIS98 transistors on the deflection board for open/short circuits. You don't even need to take them out unless you suspect something. Don't think there are many of them like 9 or 10. Doesn't take a few minutes. Worth a try.
 
Thanks all for the input. Took a run at most of the input here with no luck. Joe - your point on the Z input being the common thread made me think a bit more. After a lot of head banging, it turns out there was a problem with the Z Signal GND pin in the connector. I have since replaced the pin and all is working as expected.

Thanks again for the direction.


I wonder if there is something wrong with the z input q504.
There is something affecting both X and Y. Z input is common and so is the power section on the defection board.

Maybe it time to get the scope out and and do some comparison probing between the working and no working one?
 
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