pin2000 crt replacement

[Dann36]

Measure for DC volts with respect to ground. Anywhere up to 5 Volts..

You could also try linking the sync from the input of that amp to the output so that you are bypassing the amp on the sync line but still running the RGB signals through it..

[pinball god]

got 4.9vdc from power supply and 3.45vdc from amp input side where orange wire is and 3.45vdc from amp output where pin 13 would plug in from the vga cable. I also buzzed out pin 13 on the vga cable that came with the amp and it beeped ok. So all my readings came from the amp as I disconnected the vga cable/pc. Thanks

[pinball god]

Just had a thought, can my homemade crt to amp cabling be too long and cause a voltage drop? Reason I ask is that I had no idea what length of wiring was required and so purchased about 3m of wires of which I have left intact until I was sure of things working. So my interface cable is at least over 2m long

Update I measured 3.4vdc from the chassis where the orange wire/sync connects to

[Dann36]

Lead should be fine at that length..

The measurements sound about rite to me, but you should have left everything plugged in and running so you measured the actual sync signal coming from the PC..

I think its time to eliminate that amp as a suspect, grab your old video lead and use that to connect up to the chassis. You will need to change the pin-out to match the wells and most likely the connector housing..

[pinball god]

Dan we may be on to something??? I plugged in the vga cable that came with the amp and took a reading on the orange sync line on the amp. So the vga cable is connected to the amp and pc. I got 0.16vdc. Unplugged the vga cable from the amp only and get a reading of 3.45vdc on the orange wire connected to the amp and crt.

So before bypassing the amp I thought I'd check with you. Could it be the amp, the vga cable or both or none of the above? Thanks

[Dann36]

0.16 is not correct at all, either the sync is being held down by the VGA lead, the amp or is not coming out of the PC..

What voltage do you get on the VGA leads sync pin with only the VGA lead connected to the pc and nothing else?


Also just double check your leads are in the correct positions just to be sure your measuring rite..

[pinball god]

Thanks for the fast response. I get zero volts. My black lead goes to com, also I connected black lead to chassis frame when testing

[Dann36]

Sorry my last reply for the 0.16 Volts is wrong, i didnt read it correctly.... 0.16 Volts sounds about rite


You should be getting around the voltage you measured 0.16..anywhere around there will be ok..

with just the vga lead connected to the PC you should be reading the H sync voltage at around the 0.1, 0.2, 0.3 volts. Can you double check that? black lead on the PC case or any ground,  red lead on the vga H sync pin with the VGA lead only connected to the PC, no amp, no chassis, you shouldnt be getting 0 Volts..

[pinball god]

I contributed to the error as the actually reading was and is today 0.26vdc I figured it was so low that its close enough to zero. So we may be back to square one   reading taken from pin 13 on vga cable, third pin from bottom left of cable facing me

[pinball god]

Still no progress to a solution. Are vga cables easily available from places like jaycar as I think I'll try and make a new cable to bypass the amp. I don't want to trash the ducksan cable just in case I need to go back to the old crt. Hope that won't be the case  . Thanks

[MartyJ]

Officeworks should have a standard VGA cable

[pinball god]

UPDATE: I used vga connector from my swep1 that has a wg crt. Good news is the my crt on the rfm works with the amp bypassed and swep1 vga cable.

But before going ahead making a new cable and maybe doing away with the amp, I did notice I forgot to put an rf filter on my vga cable with amp mod connected. Could this cause the problem I have been getting? Ie. No signal in error and trashy picture???

I'll wait for any responses before proceeding any further.

I'm glad the crt is ok as its been sitting in storage for yonks and so out of warranty   

[Dann36]

Thats great...

Its doubtful that a filter will correct the no sync issue..It would help remove any noise on the lines though that would show up in the colours. But unless you have an issue like that i wouldn't bother..

If you want to keep the amp you could use it for the RGB signals and simply link the sync signal past the amp..

Or the chassis you have might just have trouble with a composite sync signal even though it does support it. So you could cut the sync trace ( should be labeled CUT FOR H V SYNC or similar) on the amp PCB and feed out separate sync signals. Your chassis might like that better.. This is assuming your amp PCB is not faulty..

Honestly the AMP PCB is not needed,  a correctly adjusted chassis will produce a better result every time. The only time one of the amp PCB's would come in useful is if the chassis you were using had very limited RGB adjustments..

[pinball god]

I found a 15 pin cable which I'm guessing is vga cable. it had a male and female plug and I cut off the female end. There's 16 wires including an uninsulated wire. Also pin 9 is missing. The wires are quite thin.

Is this cable ok to use? Also what pins need to be connected with what? I have the swep1 cable to copy maybe but really need to be sure about the cable I'm using. The  Swep1 cable is using 8 wires with what looks like a thicker black wire that may have heat shrink on it???? I think it goes to pin 6 on the chassis.

thanks

[pinball god]

Going to make a plug tonight, but have two styles I can use. The one pictured above and I just hacked up a vga/dvi cable that has larger r/g/b wires which are made up of two wires, an outer shielding type wires and a insulate inner core. Which cable is best and if the latter, I am supposing cutting away the outer wires and only using the inner. Please advise if possible