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Allen Schweitzer

This Bally guy has a question

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Has anybody ever run into anything like this before?  If so, please send me some suggestions.  I hope this posts like I want it to, because it's just putting the picutres down at the bottom while I'm typing this, and not inserting them into the body of this message.

 

I was going to list a Bally for sale.  Here is a picture of it working on my downstairs TV.

 

IMG_1083.thumb.JPG.51e66e1772b02e9b4dc8b6f464a85f23.JPG

 

Now, here is a picture of it working on my UPSTAIRS TV:

 

IMG_1086.thumb.JPG.b3c26cf748af7f43339c36e85aca374d.JPG

 

And unplugging ONLY the board from the PSU and RF box and cable, here is another working board on my UPSTAIRS TV:

IMG_1085.thumb.JPG.b69bf5143a44a21a3337a86f66e1b761.JPG

 

It's not the data chip!  Any ideas?

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Hi Allen,

What are the tv's? CRT, LCD, etc. 

Is the problem always repeatable, the first board is always B/W on the upstairs TV

 

I would replace the RF module and cable just for fun to be sure the problem isn't related to those.

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The same RF and cable and PSU were used with both boards Allen said. I'm suspecting there may be a weak connection where the RF plugs into the board that the second board doesn't have.

Edited by Gunstar

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11 hours ago, bah said:

What are the tv's? CRT, LCD, etc.

TV's are both LCD's.

 

11 hours ago, bah said:

Is the problem always repeatable, the first board is always B/W on the upstairs TV

yep

11 hours ago, bah said:

I would replace the RF module and cable just for fun to be sure the problem isn't related to those.

I tried that too.

2 hours ago, Gunstar said:

a weak connection where the RF plugs into the board that the second board doesn't have.

The 8 RF pins were all reflowed, as were all the pins on the data chip.  I think if this were the issue, it wouldn't display correctly on the TV downstairs, but what do I know?!?!?!?

 

Keep the suggestions coming!  In the meantime, I am probably going to pack it up and ship it off for a 2nd opinion.  I hope it "doesn't work" for the lucky recipient, or he may not be able to figure it out either.

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19 hours ago, Allen Schweitzer said:

Has anybody ever run into anything like this before?  [...] It's not the data chip!  Any ideas?

 

The B&W pictures probably isn't the fault of the Bally system, but, as at least one person has suggested already in this thread, it's the TV.  These LCD TVs were never meant to work with these older consoles.  You haven't mentioned trying other systems with both televisions and checking the results.  As long as the Bally unit gives color pictures on real CRTs, then I wouldn't worry about this issue.  However, if you sell the system, then it should be mentioned to the buyer.

 

I don't think that the Astrocade's RF modular is adjustable, but if it can be tuned, then give that a try.  I have had similar issues with colors being "off" (but not B&W) and tuning the RF modulator has fixed the problem on non-Bally computers (in particular this is a known issue with the Timex/Sinclair 2068 computer).

 

Adam

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It's how the TVs are picking up the RF signal.  Some TVs are more forgiving than others.  An adjustment to the RF signal of the console while plugged into the TV that is currently NOT showing a nice clear picture and sound might fix this for both TVs since the one showing B&W might be more sensitive and will result in a good picture on both.  If you have non-conductive tools you can probably tune the RF with the console on.  Otherwise you'll need to do it in increments between power on and testing to be safe.

 

This gives me trouble when working on systems for folks.  I'll get the RF tuned to work great on my TVs, mail the thing to the owner and they can't get a clear image.  Some modern TVs may never show a good RF image.  I've got one TV that has serious issues with old school RF video game consoles.

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To echo @ballyalley and @KylJoy, it's definitely the TV, and not the Astrocade, that is the issue here. One of my LCDs (a Mitsubishi from 2010) gives me a choppy, stuttering black and white picture via RF with all consoles. Running those consoles through an RF demodulator like a VCR or an old analog cable box and those same consoles work perfectly on the problem TV via composite. Ever since, I decided to run ALL of my vintage consoles and computers (of which I have several, just check my signature) through CRT TVs, with only the PS3 and Wii connected to my LCDs. 

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Allen reached out directly via email to another Astrocade hardware person who answered via email.  I figured it would be handy to post here since I'm finally catching up with months-old email now.

 

Adam

 

----------------------------------------

 

From: Michael Matte
Sent: Saturday, December 25, 2021 9:53 PM
To: Allen Schweitzer
Cc: Adam Trionfo
RE: Calling out the favors...
 
I have no explanation for this abnormality. Did you tweak the RF modulator for the TV with the B & W display to see if you could get a color display?

 

You need a very small flat edge screwdriver to do this. The 2 holes close to the RCA video output jack are for tweaking channels 3 and 4. Channel 4 is the hole closest to the RCA jack. The single hole by itself is the MAIN tweak adjustment. If tweaking the RF modulator for your first motherboard doesn't produce color, then I don't know what else you could do.

 

Some CRT TVs allow one to tweak the video display. I've seen MGA CRT TVs that would allow one to independently tweak each channel.

 

Sometimes a video issue can occur from a dirty or worn channel slide switch on the side of RF modulator. Sometimes cleaning the bottom of the motherboard connectors can help clean up a dirty display. Only the bottom of the connectors make contact with the RF modulator contacts. Cleaning the RCA exterior ground surface sometimes helps. The interior LM1889 video chip is in a socket. The last resort would be to remove the chip and clean the chip's contacts and inspect the socket pins.

 

A RF cable can be checked for a bad connection (typically at the ends) by connecting an ohmmeter at each end using alligator clips, then jiggling the cable to see if the ohmmeter detects a break in the cable ground or video wiring.

 

Finally the TV input jack may have some kind of an issue.

 

Above are all the things I know of that can be checked for a TV display that is degraded.

 

Bye.
MCM

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