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Hi All,
I have a Delta 20 and the monitor went out. I found one of the problem but the resistor at location R480 was so burnt that I can not tell the value. There are many CRT boards so I will put a picture of mine up. any help would be great. I have looked at other boards and they are not the same.
Hi all again, I see 65 people have looked at my resistor problem thank you. I just thought I would add that you do not have to remove the board it sits just under the CRT. The resistor is right in the back so if you pop open the cabinet you can see with little problem. Thanks again. better picture Attachment 327836
It might be better to get a service manual for your particular unit and look up R480, rather than us guessing. It (service manual) would also help to know what the circuit is supposed to do.
Secondly, there could be more defective components which may have contributed to the excessive voltage across R480, causing it to burn.
Hi KOC62,
I have not been able to find a service manual. I tested other things on the board and I think the transistor with the big heat sink went bad. It also melted the solder on the choke filter. I hope repairing those things takes care of the problem. I have had this Clausing Kondia with the Delta 20 for about 3 months now. I was hoping to put money into tools not CRTs. Very new to all this teaching myself.
I've gotten rid of all my CRT monitors over the years so I have nothing to compare it with.
Is the resistor equally burnt all around?
I've taken somewhat burnt resistors out and used a microscope to see if any colour bands could be guessed at.
A method I've used in the past is to trace the circuit so as to get an idea of what the surrounding parts are and circuit function and then make an educated guess for resistor value. You would need to know the power supply voltage(s) too - but even then its a risk.
Another alternative is to replace the monitor, but you will need to know how it is currently wired and the signals used in order to find an equivalent monitor.
Sorry to be of little help today.
Yep, I took the resistor out to make sure it was burnt all the way around. The only color I can make out is the gold which makes me think this is a critical value. I have found other monitors but they want $800 to $1200 bucks for old junk. The companies with the drop LCDs are just as expensive. I am trying to find a conversion board. I am checking on one now called a GBS-8220 and an older one a GBS-8219. There seems to be some sort of confusion about the type of signal TTL, or composite but if they work it is 25 bucks and an old LCD that I have many. As far as help, thanks for the reply it is always good to get input from people that have been doing this longer than me.
The resistor GOLD band means 5% tolerance, which are very common parts.Quote:
Originally Posted by aussco
I suspect the video signals to be TTL type, something like VGA signals - but can't say for sure. The composite would only need one "RCA" type cable for video and sync.
Do you know what kind of connector is used for the monitor? DB9? RCA? BNC? Just curious.
Without knowing what kind of signal comes from your unit, I can't comment on whether your GBS-8220 will work. But I do think there should be an economical means to replace the CRT monitor.
The connector on the board is a 10 edge connector. Then it goes back to the terminal block. Just to be clear do you think that if I take and wire a RCA connector to the two middle wires VID GND and VID COMP into the yellow on aTV I should see the screen and I can get rid of the rest of this stuff? Seems too good to be true.
Attachment 328006Attachment 328008
:banana: I just got an email from Ted from Parts and Smarts- He said "R480 on this board is 470 ohm, 5%, ¼ watt." I have that one. Once I get my transistor i will solder all up and see if I can make chips.... but I still want to get a converter because it is just a matter of time before the CRT goes bad for good.
NTSC video will do that - just an RCA cable. But your connector showed 4 wires going to the monitor, right? One could speculate what they are for. e.g. Vert Sync, HOR Sync, Video, Ground.Quote:
Originally Posted by aussco
The connector labelled TB17 does suggest composite video as VID COMP and CRT COMP. If you had an oscilloscope and looked at the signal we could then confirm it. But your idea to connect VID GND and VID COMP can also work, if it follows the NTSC negative sync protocol.
The four wires from the edge connector goes to CRT COMP - CRT GND - +12 GND - +12 CRT the VID GND and VID COMP come from somewhere else not that edge connector. I think RCA cable just might work! Thanks for the thinking though on this with me, it makes it a lot better.
Good to hear you are making progress.
I'm curious to hear you say it works, when you're done testing. :)
Put in the resistor, Put in the new transistor, solder down the choke filter and ... The screen came on looked great then back off. Screen is dead. :eek:Very long stream of expletives
Wired video output to Yellow on old TV got something but not usable. Biting bullet buying replacement LCD $800 upgrade.
Can you clarify? Was it a sync problem?
I got some horizontal lines and some other static. Not sure what the issue was. When I hooked up the old monitor again screen worked for about 5 to 10 seconds then would go blank again. Seems something is over heating. Hard to figure with out schematic and test points.
Another thought, which may be cheaper is to get a used computer monitor and then use one of these;
https://www.alibaba.com/product-deta...0.0.yHNFlS&s=p
I'm assuming your unit can send true NTSC composite video - RCA version.
Thanks for the thought, I already put in a new LCD. expensive but it works and now I am making chips again. Thanks for you help.
where did you get the new LCD, im havin a problem with a kondia dynapath with the screen and im looking to upgrade or fix it, the email from parts and smarts will be also helpfull.
monitech.comQuote:
Originally Posted by fxliranzo
https://monitech.com/product/dynapat...d-upgrade-kit/
Fit perfect super easy to install.
Did you fix or repair your monitor. I have a new dyna path crt. I got it, installed it in control. But now I’m either going to sell my machine or part it out. So it’s never really been used. I’d sell the crt shipped for, say 300 us continentalQuote:
Originally Posted by fxliranzo
I didn't repair it I just bought the new LCD and stuck it in there still have the old CRT but it's not working. This was some years ago you're looking at an old thread.Quote:
Originally Posted by sam_stlouis