Consider using a pin to reach into those tight connections. It'll save a lot of time tracing and errors due to that difficult chore. Just be careful that whatever tool you use doesn't cause inadvertent connections or shorts. Doo doo happens.
Thanks! I feel like I'm already learning so much from this hahaha. I'm having fun while doing it too! Quick correction to note, though. The value that was off was actually negative .889 and not positive. I'll edit it on my post as well.Consider that good news!
Good that you have found something. I will look at the schematics and get back unless someone else can provide some suggestions.
Great. You were right about the +12V connector. It was hiding behind something and came up to be about -.363V. Now am I just finding those connectors you listed and testing something or am I going to disconnect them one by one and test?There is also +12V supply. Check that also. I suspect you will find that is low also since it is derived from the +15V supply.
There are two possibilities.
1) The +15V supply is bad.
2) Something is shorting the +15V supply.
The +15V supply begins on page 71, CN202 and CN203, and supplies 0.5A
The most common fault is a capacitor across the +15V supply chain is shorting.
You can follow the supply chain by looking at the following connectors:
page 29, CN455, CN456
page 31, CN1501, CN1502
page 59, CN903, CN904
page 66, CN2502
page 71, CN202, CN203
Assume that the short is on one of the boards. See if you can disconnect boards until the +15V comes up to normal.
With all connected, I am getting a 15.08V reading at the +15V at CN202. I was getting a fairly normal reading at CN203 also. Keep in mind that the +15V that I tested earlier was the connection with the problem. It was CN904 connector. Sorry if I'm misunderstanding this a bit. :/You will disconnect one at a time and test the +15V supply line closest to the supply, i.e. at CN202 or CN203.
I attached pictures to this post. Picture 01 is a view of the CN904 connector. It is on a board above the CN203 and CN903 connector. The CN904 connector is COMING from the board below. It is not direct from the PSU. In picture 02 you have a view of the board discussed that was underneath the CN904 connector. The cable with the orange is coming direct from the PSU and is labeled CN903. This cable is getting the +15V fine. The cable to the left of that is where the CN904 cable is coming from. Now, my question is in regards to how you addressed CN202 and CN904. I'm seeing that as ONE cable/connector. Are you wanting me to test the holes in the cable? I've been testing test points on the board which you can see in the pictures. They are labeled V+15, V-15, etcetc. What is the difference between CN202 and CN904? I will triple check the voltages but they remain the same at the test points from what I previously posted. Thanks again chips. You're being a ton of help. I appreciate it.Make sure you are measuring at the connectors correctly.
CN202 and CN903
There are no electronic components between CN202, CN903 and CN904.
If there is no +15V at CN904 then there is a loose connector or a broken wire or connection.
Examine visually very carefully.
When you say test the specific pins, am I testing the pins within the cables to check the voltages? I've been testing the test points on the board where the voltages are labeled. Sorry for confusion. I ask because the pins on the cable are very small and I wouldn't be able to get the multimeter lead into them without something else.There is no IC1167, IC1168 or IC1169 shown in the photo posted by the op.
I still would like to know the voltages at CN903 and CN904.
This is a direct trace from CN903 pin-1 to CN904 pin-3 and should read +15V.
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by Jake Hertz
by Jake Hertz