BLACK KNIGHT 1981

Thank you Iceman5000 & L. Satan for your comments. When you mention Caps Lock are you referring to the Pop Bumper or something else. I did
repairs on the pop bumper to replace the skirt . Regarding your comments L. Satan I agree with your comments although everything was operating
perfectly until I undertook replacing the lamps-I have articles clearly describing what must be replaced but the 40 pin has been operating perfectly and
the GI was operating perfectly as well. Firstly, I will address Iceman's suggestion once I know exactly to what he is referring. Thank you again for your
advice I do have all the necessary tools- Logic Probe, DMM, Anna Tek Blue ESR Tester.- whether I am using them properly is another question!!

The continuing pulsing of the outhole solenoid after having tested everything around the solenoid & switch & checked continuity of all switches
in the column is really puzzling.

#5 10 years ago

SBS

o-din

Pinside+ Addict

11y 158K 58,764

OP
Quoted from Streetras:
I COMMENCED IMPROVING THE OPERATION OF THE MACHINE AND HAVE CREATED SEVERAL TECH ISSUES:

Sounds like you should have stopped while you were ahead. But if you are over it and it is still in Ca., let me know.

#6 10 years ago

???

Streetras

Inactive member

One must take chances to improve the game's operation and I have lots of time to work out these
relatively minor issues. The game is from CA but is now in CAN(Canada!!)

#7 10 years ago

TAB

terryb

Inactive member

I would pull the solenoid fuse and work on the switches first since it is possible for some flaky switch circuitry to fire a solenoid.

What do you mean when you say all the switches in column 4 are shown as being issues? Do you mean they are showing as closed when they shouldn't be, or something else?

#8 10 years ago

HAN

HHaase

Siegecraft

13y 89,550 3,094 4 12

If the solenoid is pulsing, and you're showing all of column 4 as stuck, then you're dealing with a switch matrix issue. First thing I'd suggest is disconnecting the two switch matrix connectors from the driver board, and see if it still shows the same stuck column. This will isolate it between being a board problem or a wiring issue.

The GI circuit for System 7 is a troublesome nightmare. A picture of the lower section on your power supply board would help to identify how bad yours is. 9 times out of 10, a GI problem in black knight is attributed to fried power supply connectors, WMS chose a connector that doesn't have a sufficient amperage rating for what they tried to do. (In fact, their GI lighting issues continued all the way until Pin2K was released, System 9-11 and WPC still suffer GI wiring issues.... just not as badly)

-Hans

#9 10 years ago

???

Streetras

Inactive member

To terryb I mean that when I go into the switch test (03) the machine indicates problems with all Column 4 switches-
#4 Right Coin Switch, #12 Right Outlane, 20 - Outhole, 28 (not used) 36- Jet Bumper & 44 Left Ramp Rollover.(all indicating
closed and all have been checked 2X to ensure they are open. Your suggestion to address the switches first is an excellent idea.

As to HHaase I have pulled the 2J2 and 2J3 connectors and the switches continue to indicate that the switches are closed.

You will not believe it but the GI connectors look perfectly new-no discolouring whatsoever. I put my DMM to the transformer
to check the voltage from the 2 leads to the power supply board and one reads only 5.7v while the other(right hand imput ) shows
0 voltage. I am curious whether both connectors should show the same voltage and whether 5.7v versus 6.3v is sufficient to
cause GI issues.
Thank you for your comments.
Bob

#10 10 years ago

TAB

terryb

Inactive member

I think you mean row 4 rather than column 4.

The first thing to check when you have a row problem like this is that the row wire is not shorted to ground. By removing the connectors as HHaase suggested you have done this and verified the problem is not with the playfield wiring. Therefore you have a board problem with the row 4 circuitry.

Next step is to check the voltages on all the rows at 2J3 (with the connector removed) and I think you'll find that pin 6 (row 4) reads 0 volts where the other rows will read 12 volts.

#11 10 years ago

???

Streetras

Inactive member

Thank you terryb -I mistakenly thought the rows where vertical and the columns were horizontal. I will follow
your advice and check the voltage at pin 6 to see whether it is a board problem.
One issue I would like to resolve is the lound hum coming from the transformer and whether both leads to
the power supply board from the transformer should show voltage as well as whether a 5.7 v reading is
too low.

Thanks to you both for showing an interest and providing me with excellent advice.
Bob

#12 10 years ago

JEF

Tridentphoto

Pinside member

Edmonton, AB

10y 33,300 280 3

Where are you in Canada?

#13 10 years ago

???

Streetras

Inactive member

Terryb - I turned on the machine and with the DMM measured 4.9 v on each pin except #6 which indicated 0.8v. You mentioned that the
3J3 pins should read 12 v. Interestingly, the 12v post on CPU boar shows 13 V and the 5V post shows 4.8V.
Bob

#14 10 years ago

???

Streetras

Inactive member

Hello Tridentphoto:
On the other side!!!- Halifax, Nova Scotia

#15 10 years ago

TAB

terryb

Inactive member

OP
Quoted from Streetras:
Terryb - I turned on the machine and with the DMM measured 4.9 v on each pin except #6 which indicated 0.8v. You mentioned that the 3J3 pins should read 12 v. Interestingly, the 12v post on CPU boar shows 13 V and the 5V post shows 4.8V.

Sorry, forgot we're working on a system 7 game. I'm not as familiar with them, but they may use 5 volts on the switch matrix instead of 12 as the newer systems do. In any case, the problem is with the one circuit reading 0 volts. I don't have any system 7 schematics, but if someone could point me to some on the web I could narrow it down further (I did a quick search and couldn't come up with any schematics). Of course at this point the question is if you're up to replacing components on the board?

On the transformer issue, are you reading across the two leads or from each lead to ground? Since this is an AC circuit you should be doing the former. Again, not that familiar with system 7 but I would not expect a loud hum from the transformer.

#16 10 years ago

???

Streetras

Inactive member

Terryb- I measured at the transformer the 2 yellow wires that are the GI wires going to the power supply board. One reads 5.7v but there is no reading on the other connection. The readings are from each lead to ground AC. I am up to replacing the units on the board and have someone else who is very capable to do that work. I am relatively new to board work and major work is best to one highly qualified as I don't wish to compromise the board. I have accessed the schematics online and will review the source and place on this forum. Thank you again for your interest.
Bob

#17 10 years ago

???

Streetras

Inactive member

Terryb. You can view schematics of the Sys 7 MPU board, and the 2 schematics of the Driver Board at http://pinball.flippers.info/system6resources.asp The Driver Board may be a system 6 but is exactly like the 7 in my BK book. Hope that this may be helpful. Bob

#18 10 years ago

TAB

terryb

Inactive member

If you look at the driver board schematic, on the left side is 2J3 pin 6. That connects to IC15 pin 9. The problem is with either the pull-up resistor (R80) being open or the IC or the cap (C42) shorting to ground. Could also be a broken trace in that area.

On AC circuits you read from hot to neutral rather than hot, or neutral, to ground. If the two yellow wires are hot and neutral for the GI circuit then you should read across them. Reading from either one to ground will give a reading of half as much. If you get no reading on one of them, that sounds like a problem. Hopefully HHaase will jump back in on the GI because I'm just not that familiar with it on system 7. The system 7 power board is different than the system 6 power board so the schematics referenced above don't help much (unfortunately the difference being the GI was added back into the board).

I would disconnect the transformer from the power board and again check the voltages to make sure something isn't pulling them down (this would also cause your loud hum).

#19 10 years ago

???

Streetras

Inactive member

Terrryb I took your advice and received a reading of 6.6 V AC from the GI outlets from the transformer. I will do as you suggest and disconnect transformer connections at the power supply board and see whether the hum disappears. Based on the articles I have covering Systems 3-7 the 1C15 could be the culprit and the R80 and the C42 also need to be assessed since that is the chain. One difference between 6 & 7 systems is the transformer is on the bottom of the cabinet in my unit. I will attempt to show 2 pics of the switch are on the board and GI area on the supply board. Thank you for your expertise and time. Bob[Black Knight 001.JPGBlack Knight 003.JPG

#20 10 years ago

HAN

HHaase

Siegecraft

13y 89,550 3,094 4 12

The good thing is your GI section doesn't look too fried. The yellow and white/yellow wires are of course the output from the power supply to the GI lighting circuits. That empty connector all the way on the bottom right is the input, and the red/orange wires are the signal for the relay. The relay is 'normally closed', meaning the GI should always be ON except when the relay is signaled to turn it off. Fuse looks good visually, but always check with a multimeter. If you go into the solenoid test mode, it's solenoid 11 that triggers the GI relay, you should see/here it triggering. It's also possible you've got a stuck solenoid circuit on your driver board, pulling the red/orange wire connector would show if that's the case. To test the input voltage, you'd actually set your meter to check AC voltage, and put one test lead on each leg of the input connector. 5.7v is fine for the GI.

The GI circuit is brutally simple. It basically goes from the lights, through the relay and fuse on the power supply, and then to the transformer. Yours is probably the ONLY system 7 GI connector I've seen that still has the factory IDC header, and it isn't melted. You'll want to quickly replace that molex connector with the high amperage version. Ed at GPE carries them as part number 09-50-8091, and you'll also want the high amperage pins on that connector, # 45570-3050 (only need those pins on this connector, the rest can use standard trifurcon's)

Also, the 12v DC line is not regulated in any way. It's only going to be approximatley 12v, but could be anywhere from like 10-15, and any of those is good. It's only used on the reset circuit and exact voltage is not critical in the least. 4.8v on the 5v line is a bit low, but not too bad.

#21 10 years ago

HAN

HHaase

Siegecraft

13y 89,550 3,094 4 12

Oh, I forgot to mention, the switch matrix area is one place not to learn how to solder. The lamp matrix resistors create a lot of heat over the years, and it tends to really heat soak the driver board. Since the switch matrix section is directly above that, and heat rises, it suffers badly from heat damage. Not only does this cause chip failure, but also very weakened bonding of the traces/pads to the board.

I'm not trying to trump up repair business for myself, just trying to make sure you know it's a tough area to do solder work on sometimes.

-Hans

#22 10 years ago

???

Streetras

Inactive member

HHaase - Thank you for those excellent observations and the wise advice concerning the GI connectors and the comment about "do-it-yourself" at high risk. I believe this is a task for one highly qualified to replace the necessary components and save my board from being "hacked" (by me)!!! I will now digest the info you & Terryb have provided. I will do the tests you recommend and will then proceed to having the issues addressed. Thank you for your assistance. Bob

#23 10 years ago

???

Streetras

Inactive member

I went into solenoid test mode and the solenoid #11 did trigger the GI Relay- (saw and heard it). When you refer to the red/orange wire connector, are you referring to 2J13 (Special Solenoid Imput) or 2J7 (Lamp Row Driver? My reason for asking is I am colourblind which really helps!!! and I notice that 2J7 the wires are red. (The 2J13 lines appear orange only. I will perform this test once you can confirm the connectors you are referring to.
Bob

#24 10 years ago

???

Streetras

Inactive member

Terryb - Regarding a possible trace issue on the 2J3 pin I tested continuity between pin 6 and pin 9 in 1C15 and it was fine so no problem with a broken trace between the two on those pins .In the article at www.pinrepair.com/sys37/index3.htm which I downloaded in 2009 but may not be there now, the author mentioned on p. 33/86 If there is a column problem at 2J2 it's usually 1C17 and 18 and if it is a row problem then check 1C15 and 16. Personally, he stated, I find that the column chips to be more of a problem than the row chips. Beyond that ,the driver board PIA 1C11 (6821) could also be the problem since it interprets all row and column date. The PIA can be checked with Leon's test chip (I do not have) Anyway, lots of info for me to check out. Bob

#25 10 years ago

???

Streetras

Inactive member

Terryb - Regarding the loud hum from the transformer I pulled the fuses on the power supply board and noticed only a slight hum when I removed fuse F5 which comes from the BR1 - bridge rectifier and goes to plug 3J1 which handles all input voltage from the transformer to the power supply. Could the BR be the issue-I gather they can be tested for a diode reading but probably must access from the back of the board unless the metal cover can be safely removed. Any suggestions? Bob

#26 10 years ago

TAB

terryb

Inactive member

OP
Quoted from Streetras:
In the article at http://www.pinrepair.com/sys37/index3.htm which I downloaded in 2009 but may not be there now, the author mentioned on p. 33/86 If there is a column problem at 2J2 it's usually 1C17 and 18 and if it is a row problem then check 1C15 and 16. Personally, he stated, I find that the column chips to be more of a problem than the row chips. Beyond that ,the driver board PIA 1C11 (6821) could also be the problem since it interprets all row and column date. The PIA can be checked with Leon's test chip (I do not have) Anyway, lots of info for me to check out.

Sometimes too much information just muddies the problem. In your case the problem is somewhere as I described above. You can check the resistor with a DMM, and since the cap would have to be shorted to cause this problem you can also test it with a DMM. If both of those look good then it's most likely the IC.

You can just test the bridge from the back. Also make sure that circuit isn't over-fused.

#27 10 years ago

???

Streetras

Inactive member

Terryb - I will do the test right away. Thanks a lot. Bob

#28 10 years ago

???

Streetras

Inactive member

I tested R80 and the reading was .776 and all the other resistors in the row had the same reading. The C 42 had a reading of .64 whereas the remaining
caps had readings of 1.9. Although the 1C15 may still be a culprit, I gather that one may conclude that the C42 needs to be replaced. Thank you for the follow-up. Bob

#29 10 years ago

TAB

terryb

Inactive member