Ms8 26su

[Retroman839]

Lovely raster
Lovely neck glow
Can’t get image ?


I have tried 2 jamma looms and 2
Psu
1 happ psu meters the 5v
On both ..

Either it don’t like the 19 in 1
pandoras I’m using to test .
Also a Puznic jamma board .

No image .
I have tried connecting the H sync & v sync ..
Even though I know it wasn’t going to bring and image up on screen ..

Screen does sync when power is applied to my video source .

Is this duel res ?
If set to 24 kHz would I
Get no RGB?
Poss main cap on kneck pcb ?

 

[eliotcole]

I've got 2x Virtua Racing and 1x Virtua Fighter if you wanna test medium res ... but ... they are in the loft and I'm unsure of current functionality. 👍

 

[Retroman839]

So if I increase the flyback brightness
Sometimes screen goes overdrive with a colour

Sometime red
Sometimes green
Sometimes blue

 

[Retroman839]

I've got 2x Virtua Racing and 1x Virtua Fighter if you wanna test medium res ... but ... they are in the loft and I'm unsure of current functionality. 👍

If I can power that pcb

 

[tb2000]

MS8-26 is dual sync. Check to see you've got it in 15k mode.

 

[councilface]

Yep, looks to be in 24khz

 

[M K L]

Check for 120VDC on one of the big resistors (R305 or 315 or 325) on the neckboard. If there's no voltage, R570 (near the flyback) is open.

 

[Retroman839]

MS8-26 is dual sync. Check to see you've got it in 15k mode.

Checked it was in low 15khz 😌

 

[Retroman839]

MS8-26 is dual sync. Check to see you've got it in 15k mode.

Checked it was in low 15khz

Check for 120VDC on one of the big resistors (R305 or 315 or 325) on the neckboard. If there's no voltage, R570 (near the flyback) is open.

yeh I’m hoping it is that flameproof resistor ..

I have coulor tinted raster also

 

[Retroman839]

Check for 120VDC on one of the big resistors (R305 or 315 or 325) on the neckboard. If there's no voltage, R570 (near the flyback) is open.

This is what I got on r570


Which is slowly tricking down
2 mins passed and
K ohms reads OL open circuit ..

So I change this and caps in the circuit which most likely caused the issue ?
4.7 ohm fusesble
Or fire resistant ?
Thanks 👍

 

[tb2000]

Remove the resistor from the chassis to test and make sure.

 

[Retroman839]

Will do 👍
Do I need to change rectifier diode also ?

 

[M K L]

Will do 👍
Do I need to change rectifier diode also ?

If you had checked voltage (which is now understood you hate to do LOL) you would know.

 

[Retroman839]

Will go over this one as well whilst at it

 

[Retroman839]

If you had checked voltage (which is now understood you hate to do LOL) you would know.

Nah love
It 🥰I’m thinking of putting it back on before I take resistor out ..
More testing the better 😁👍



Will show you the voltage I get on them RGB amp resistor legs ..
Bare with I got 2 kids 🤣 Not sure I can get back at it tonight though ,

🤞 hoping for 0 volts ..
But not a faulty flyback just bad dry caps

 

[Retroman839]

 

[Retroman839]