texasmame
Well-known member
K. I'll hit those up ASAP and report back. Thx!
K4600 Video Interface board information
- Thread starter KenLayton
- Start date
K. I'll hit those up ASAP and report back. Thx!
OP
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KenLayton
In Memoriam
The 2N3904 transistors are the world's most common and cheapest transistors out there. Everybody stocks them: Mouser, Jameco, Digi-Key, Radio Shack, etc.
You can even buy them on ebay.
You can even buy them on ebay.
texasmame
Well-known member
No dice - still not working after replacing 201 and 202
OP
OP
KenLayton
In Memoriam
Check zener diode ZD201 (3.9 volts @ half watt).
Check all the resistors in the black level circuit: R204, R204, R206, R220.
Check electrolytic capacitors C201 and C202.
Check all the resistors in the black level circuit: R204, R204, R206, R220.
Check electrolytic capacitors C201 and C202.
texasmame
Well-known member
Will do but, on the parts list/layout you have in the thread, it lists the 6.8v Zeners and I picked those up instead. Can the larger voltage be used without issue, kinda like larger voltages on caps can?
EDIT: All resistors (203, 204, 206, 220) are within tolerance but 220 is the same as 203 - a 1K resistor. Same on the other boards I have as well. Schem shows 680. Caps AND Zener (proper one used) replaced to no avail.
AND the black pot tests good on the resistance check with a multimeter (changes when turned).
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texasmame
Well-known member
As of now, I've replaced on this P317 that has the black and horiz pots on the side:
TR201
TR202
ZD201
C201
C202
Black pot tested good. Resistors in black circuit test within tolerance with one end removed from board as to be out of circuit.
Also replaced TR206 and TR209 hoping to get at least green back if those were bad - all no change.
Tested my one known good card on two chassis - works. This bad on tested on same two two chassis - no workie.
TR201
TR202
ZD201
C201
C202
Black pot tested good. Resistors in black circuit test within tolerance with one end removed from board as to be out of circuit.
Also replaced TR206 and TR209 hoping to get at least green back if those were bad - all no change.
Tested my one known good card on two chassis - works. This bad on tested on same two two chassis - no workie.
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OP
OP
KenLayton
In Memoriam
And you're remembering to plug in the cable from the neckboard to the video interface board?
Is there a problem with the white connectors on the bottom of the P317 boards?
Is there a problem with the white connectors on the bottom of the P317 boards?
texasmame
Well-known member
texasmame
Well-known member
Continuing this thread here as to not further clutter Ken's thread:
http://forums.arcade-museum.com/showthread.php?p=2750395#post2750395
http://forums.arcade-museum.com/showthread.php?p=2750395#post2750395
OP
OP
KenLayton
In Memoriam
A friend just bought a box of a dozen video interface cards for the 4600 monitor. I went through them and repaired them but came across an unusual one. This one is a P298 board, but with a real nice pot attached to the edge of the board and a nice knob on it. It's too good of a job....looks like the factory might have done this. Why couldn't ALL of the video interface boards have this "easy-to-adjust" black level pot installed originally?
Attachments
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OP
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KenLayton
In Memoriam
Bumping this old topic.
when you click on the links...
FranticKoala
Member
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FranticKoala
Member
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FranticKoala
Member
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FranticKoala
Member
Links Fixed
Parts list and board layout:
http://www.arcade-museum.com/manuals-monitors/Wells-Gardner-P305-parts-layout.pdf
Schematic:
http://www.arcade-museum.com/manuals-monitors/Wells-Gardner-P305-schematic.pdf
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FranticKoala
Member
Links Fixed
Parts list and board layout:
http://www.arcade-museum.com/manuals-monitors/Wells-Gardner-P306-parts-layout.pdf
Schematic:
http://www.arcade-museum.com/manuals-monitors/Wells-Gardner-P306-schematic.pdf
