Main > Monitor/Video Forum
How to use SCART for our hobby
Paradroid:
Out of interest, has anybody ever tried a Bang & Olufsen CRT for MAME/SCART purposes? In particular, the MX series? These units still seem to fetch a fair price and I was wondering whether they're actually any good or the high price is just driven by collectors and hype.
Zebidee:
--- Quote from: Paradroid on October 10, 2011, 01:46:02 am ---
I'm not talking about interlace flicker but a slight pulsation that is quite obvious when looking at a stationary image ... My question is this: is there an obvious fix for this kind of issue or would a repair be way too expensive to bother?
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Sounds like horizontal oscillator or something like that. But who knows for sure? The trouble is that every TV is different so you may be better off asking on a service tech forum somewhere. Or taking it to a local repair guy (~$150). Regarding value, refer to my earlier discussion on taking the tube from your Grundig (later model Grundigs use the nice Phillips tubes with bonded yokes) and using a brand new custom chassis. You can get them from www.jomac.net.au (Australia, where I get them) or also from 8liners I believe (US). About $250 for a new chassis and much easier to service or repair yourself. Image quality will be as good or better than the Grundig was in its prime.
--- Quote ---I see that replacing caps is a big thing around here but I'm not sure what that remedies.
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I'm not such a big fan on applying cap kits. While this partial blanket approach may be a good idea for tired old arcade monitors that have been used in hot/humid environments, it rarely solves underlying major problems. Better to get an ESR (low ohms) meter with which you can test your caps without removing them from the board! That way you can tell exactly which caps need to be replaced.
--- Quote ---Thanks for all the advice so far! :)
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Thanks! I just got a warm fuzzy feeling :)
Zebidee:
--- Quote from: Jollywest on October 10, 2011, 03:37:47 pm ---I'm trying to connect a Sony Trinitron KV-X2502U to a Jamma PCB & PSU via scart.
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You may have sync problems because Jamma PCBs typically output fairly high sync and RGB signals. They might be 'out of range' for your Sony. You would have to test the voltages of these while on and 'in-circuit' (ie plugged in). Which I know is a pain because you have probably insulated everything etc.
--- Quote ---After I'd put the resistor in and checked it again it measures at 50 Ohms, is this right?
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Apparently no, but I'm not sure what else is in circuit or if you are shorting somewhere. Don't forget that you should test ohms (resistance / impedance) while off and you need to be aware of whatever else is in the circuit (e.g. many TVs RGB inputs are 75 ohm 'terminated'). For example, a circuit with two 100 ohm resistors in parallel will give 50 ohms resistance. Did you test your resistor before putting it in?
Try testing the voltage available to pin 16 while on and in circuit. It should be in the range 1-3 volts. Then try doing that for R-G-B. It should vary between around 0-1 volts.
Zebidee:
--- Quote from: Paradroid on October 12, 2011, 01:11:50 am ---Out of interest, has anybody ever tried a Bang & Olufsen CRT for MAME/SCART purposes?
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They should work well. There is no reason why they shouldn't.
Jollywest:
@Zebidee
Thanks for the detailed response.
I did test the resistor but while it was on a pcb so it may have been in parallel with another resistor. Hopefully I'll get chance to check tonight and try those voltages as well.