WPC power board testing question

[biglouieuk]

hi all..

I wonder if I could ask a question about the WPC power board on my Hurricane? All boots up, its in bits at the moment, so no full test.

I wanted to check voltages on the power board, to see what we currently have.

Am I right in saying this is all DC power on the TPs, so set the meter to DC voltages.

Then there are these test points?

TP1 (+12v unregulated):
TP2 (+5v):
TP3 (+12v regulated):
TP6 (+50v):
TP7 (+20v):
TP8 (+18v):

Is it ok to drop the black lead on the meter onto say, the top right corner of the power board to get a GND? And then probe each TP with the red lead.

I appreciate super noob question, and that I probably shouldn't be doing this if I don't know this already, but I would like to learn!

Thanks in advance :0)

Rob

 

[Fubar]

Is it ok to drop the black lead on the meter onto say, the top right corner of the power board to get a GND? And then probe each TP with the red lead.

That is OK for DC voltages but some might be AC depending on the TP (looks like most of them are DC in this case). For checking voltages on my machines I often check it at the fuses as they're usually labelled.

You should really get a manual/schematic detailing what each test point corresponds to (sorry I'm not super familiar with WPC). Looks like there is a schematic with the Test Points here: https://www.pinwiki.com/wiki/index.php?title=Williams_WPC#WPC-89_Power.2FDriver_Board

 

[biglouieuk]

Thanks for coming back to me, looking at the schematics for this now to see if some are AC at test points.

It's handy that the TP also has the expected voltage printed on the board too!

Good tip on the fuse check..

 

[biglouieuk]

Some work to be done

TP1 (+12v unregulated): 15.6v
TP2 (+5v): 5.1v
TP3 (+12v regulated): 0.3v
TP6 (+50v): 15.07v
TP7 (+20v): 22.61v
TP8 (+18v): 0.42v

 

[CHRIS B PINBALLS]

It’s not too bad
Tp1 15.6 v is fine hence unregulated
To 2 good
Tp 3 and 8 wrong but the 12v is regulated from the 18v
Tp7 good
Tp6 15v not good

 

[biglouieuk]

Thx Chris. Your post made me go back and check over the board visually.

2 fuses had blown. F111 and F114. I hadn't noticed and had assumed, that because I'd checked all the fuses before, that they were good. With all the work I'm doing, I must have shorted something.

Both fuses replaced and things look good on the test points, at least I think the do!

TP1: 15.2v
TP2: 5.1v
TP3: 11.91v
TP6: 74.4v
TP7: 22.3v
TP8: 18.2v