Thor SCART AVC100 Problem

[zakruowrath]

I seem to be having an issue with my Thor SCART ADC100. The picture is darker than normal and there's no sound. I tested each individual cable with and without the switch with the Framemeister and each cable is fine when it's not plugged into the switch. It also seems to not like composite video as sync, but works fine with CSYNC. The gain on the back of the unit did nothing, I'm assuming that's only for composite video.

I took the unit apart and measured the three voltage regulators. U1 and U6 are L7805CVs and tested fine 10.04 V-In/ 5.02 V-Out with the unit in standby and 9.71 V-In and 5.00V Out with the unit ON.

Then I measured the L7905CV which is at U34 and only got 0.75 V out and 0.50 V In. So I'm thinking that's my problem. Is there anyway someone could test their own unit and see if that's the normal voltage? Also all the capacitors looked fine no leaking or bulging, I may replace them all in the future with high quality Panasonic.

When I had my MegaDrive/CD/32x and N64 hooked up, I switched to the N64 input and the MegaDrive had cross talk interference on the N64 input. I wouldn't turn on multiple systems at a time but wanted to know if it was normal if two systems are on at once?

I do plan on getting a new 9V 1 Amp power supply being the one that came with it is a RadioShack 9V 500mA and it's outputing 11.2 V not being plugged in to the unit. Just to be sure, the unit uses a positive centre conductor barrel 9V at 500mA? With 1 Amp I wanted to make sure the unit has enough amperage even if it only takes 500mA. Also what is the barrel size?

It did come with the original power supply, so theoretically I could get a step up transformer, but I do want to use the units clock function as well and not keep a step up transformer on all the time.

Any help is wonderfully appreciated

[BuckoA51]

I can't imagine you're missing anything. Of the switches I reviewed that one had some of the best performance of all, definitely no crosstalk and a consumer grade switch would never reject composite video for sync as that's the SCART standard.

[zakruowrath]

I can't imagine you're missing anything. Of the switches I reviewed that one had some of the best performance of all, definitely no crosstalk and a consumer grade switch would never reject composite video for sync as that's the SCART standard.

Now I'm thinking it's a capacitor or the voltage regulator. Possibly the person who had it last had the polarity incorrect and it blew something on the board. I did test a power supply I found with 12v 2A centre conductor positive and same thing, the 7905 shows 0.7v and 0.5v, the other regulators are doing fine, they even converted 12V to 5V perfectly. Of course I'm still going to get a proper 9V 1A power supply.

That particular voltage regulator possibly controls the audio circuit, an amplifier circuit and/or a filter circuit, guess I'll have to check all the caps and transistors. I did test the composite video rca jack out and got the composite video signal on my AV Famicom which uses composite video as sync. Still no RGB image thou when I use it. The audio jacks still had no audio either. However trying to use the front AV composite video port with both the AV Famicom and the N64, the framemeister didn't like it at all, the picture came on for a split second, was pretty wavy and then went away.

Also could be that since all my SCART cables have capacitors in them, would that be darkening the picture in RGB? At this point I'm fine with just replacing most of the components on the board, shouldn't cost too much, just want to get it going.

[viletim]

zakruowrath,

I have no idea what this equipment is, but I can tell you that's a power supply which requires an AC input, not DC.

[zakruowrath]

zakruowrath,

I have no idea what this equipment is, but I can tell you that's a power supply which requires an AC input, not DC.

The smile you just put on my face for not realizing what is in plain print on the back of the unit and on the original UK power supply. I can't believe how simple the problem was, thank you so much Tim!

So for anyone searching the internet in the future that got a DC power supply with their Thor AVC100 SCART Switch, you need an AC 9V 500mA or more power supply NOT a DC 9V 500mA.
The original NES-002 AC power supply works perfectly for it.

Thank you again Tim Worthington I could hug you right now

And thank you too for your help BuckoA51, now to just find a manual for this thing