Baywatch - Suddenly went dead

[swinks]

I thought I would be best to start my own thread to not confuse issues and not take over Blktgr74's thread, sorry mate.



I had a sudden issue over the weekend while playing my Baywatch. I was aware of some items that needed correcting but still chasing parts to do a playfield shop.

Issue occured like this
1. was playing a game and all fine, and played a second game and made it to a new video mode where you had to make your character run along the beach by hitting the flipper buttons really fast.
2. played a third game and the sound effects were not there and kept getting the Hoff saying "we will be right back" constantly through the game so something wasn't right as that is normally the ball launch when you lose a ball (I think as haven't played alot)
3. turned it off and waited a minute then turned it back on and had all lights, but no dmd, no sound sequence, no ball check and no boot up
4. lifted the dmd board out and noticed that the F8 fuse blew on the Playfield Power Board (PPB) which is a 4amp which looks after the 50volt supply to the coils - EDIT - this was not the case as the fuse has 2 balls of solder on it giving the effect of blown but was still intact
5. though did replaced the fuse and turned on and nothing, went to pull out the fuse to check and broke the fuse puller and the multi meter had dead batteries - so can't check now until tomorrow as night time now.

I am still waiting on one part (dmd power supply cable) as when I first got the machine it was resetting so suspect the cable etc is a issue not getting the proper 5v. Once I get all the parts I was going to do a shop out of the playfield as some of the flipper coils do not have a diode and incorrect flipper coils amongst a bunch of other switch tidy ups (change out the washing up sponge) etc

could this missing diode on the flipper coils be the cause???? or the rapid flipper activating

anyone have any clues, any advice would be much appreciated


some findings to be posted in a minute

[swinks]

a pinsider told me to check the ribbon cable between the cpu and the dmd board, by swapping it around and isolate a issue with the cable. Stupid me did not take any photos initially and blind freddie did not have the reading glasses and assumed the cable would plug into a notched plug base so didn't take notice of the cable orientation -  

after some research of the manual which didn't show much, then the net on ribbon cables states commonly the red wire on one side is the no:1 wire. Can someone confirm this please and even better compare my photos to their baywatch please.
lesson learnt take photos and sketches

attached are the screen shots for the 2 boards for the 2 plugs
and
2 photos, one the cpu ribbon (CN22 plug) which I believe is correct to industry standard, the other is the dmd plug (J3) which I have plugged in opposite to industry standard so board specs can be seen with the red stripped wire on the 25/26 end (no I did not power up - just for a photo and have already swapped around)

Can someone confirm that my beliefs of the cable plugged in is correct which includes the dmd one being swapped around.

I still haven't powered up a thing as did not want to risk further damage

[Blktgr74]

Red should be on pin 1. hope this helps

[swinks]

I still can't check any voltages as the fuse in my multi meter is blown and no places locally have the one I need, not sure when that happened but waiting on some of those fuses and a pinball pack of fuses to come care of Homepin  

I did disconnect the below ribbon and checked all the plugs and chips by pushing them all into place and powered the machine up and noticed that none of the 3 cpu leds light up at all - so appears power supply is a issue to the cpu

I also attached a photo of what appears a hacked power cable and a screen shot of the power board - the hack plug connects to CN5

Black wire does marry up with ground
Red wire marry's up with +5V

I have ordered a replacement lead from pinballlife to correct this as this current plug is a tad loose

[swinks]

Red should be on pin 1. hope this helps

cheers mate

[Blktgr74]

I still can't check any voltages as the fuse in my multi meter is blown and no places locally have the one I need, not sure when that happened but waiting on some of those fuses and a pinball pack of fuses to come care of Homepin 

I did disconnect the below ribbon and checked all the plugs and chips by pushing them all into place and powered the machine up and noticed that none of the 3 cpu leds light up at all - so appears power supply is a issue to the cpu

I also attached a photo of what appears a hacked power cable and a screen shot of the power board - the hack plug connects to CN5

Black wire does marry up with ground
Red wire marry's up with +5V

I have ordered a replacement lead from pinballlife to correct this as this current plug is a tad loose

I know that plug. This is what mine looks like

[swinks]

thanks for the photos  

when looking at your plug and the schematic, I could be wrong but it looks like
one black goes to - key ?????
other black goes to - +5VDC

this could mean a grounding problem and could solve a issue with your machine that you were talking about on your thread / boot up problem

[Blktgr74]

Ok thanks ill look into that plug some more and see what's what.

[Blktgr74]

I've got black on 1&2 and red on 4&5 which should be right?

[swinks]

yes you are correct and mine is ass about - I was looking at the plug on the board diagram the incorrect way.

But with mine - it was working so will have to trace the wires further down and check that the wires are ass about there as well and not causing other issues.

[Blktgr74]

If you need any more pictures as a reference just sing out happy to help out.

[swinks]

Ok, testing has started but someone will have to help me narrow done the problem

- got a fuse for the multimeter so finally can do some testing

- I am aware the power wires on the power board are ass about and have drawn a sketch so will work out if things are crossed over down the line later today but do know that one set of black and red go to the dmd itself and the other set to the dmd board. I know it worked in the past so will not mess around to much at this stage.

- first test: disconnected the leads off the dmd and dmd board and tested voltage at the top rhs test points and the CN5 outlet of the power board with the following results:
* ground / +5v = 4.83 v
* ground / +12v = 11.77 v

- second test: connected power leads to the dmd and dmd board and got the following results:
* ground / +5v = 0.07 v
* ground / +12v = 12.77 v

- third test: with just the dmd power lead disconnected and got the following result:
* ground / +5v = 0.07 v

- fourth test: with the dmd power lead connected and the dmd board power lead disconnected and got the following result:
* ground / +5v = 0.25v

- fifth test: disconnected both power leads and did a machine test as I noticed in the first test the light sequence was on. I pushed start and was able to have a game with flippers etc working.


So from research I know these large dmd's need a good 5v source and with nothing connected it is just under that but when either dmd or dmd board is plugged in, it drops to nothing. I know the game works and the cpu isn't dead (yeah).

Can someone point me in the direction if something has failed on the power board as my gut thinks that but I am definitely no expert with electronics or could it be a bridge rectifier.

Help Please, and explain for a dummie please :)

[swinks]

forgot to mention with the power leads disconnected and game making sounds and operating the left and middle cpu led were constantly on when I had a quick look - if that helps at all.

[beaky]

your +5 volt rail is low even with out the dmd connected "+5v = 4.83 v"
It could that the large transistor on the heat sink is faulty or a faulty capacitor on the power supply.

the +5 volts gets its supply from the +12 volts so i doubt its the bridge.

there is one more test you can try. with the dmd and controller connected
Black lead to gnd
Red lead to the left side of R6 (the big white resistor under the heat sink)
Then Red lead to the right side of R6

if both tests show 0.** volts then the fault is in the power supply
if one test shows +5v and the other shows 0.** volts then the fault is on the dmd driver board

But going back to what i said at the top of this post 4.83V is to low at the power supply so you need to sort that out 

 

[swinks]

your +5 volt rail is low even with out the dmd connected "+5v = 4.83 v"
It could that the large transistor on the heat sink is faulty or a faulty capacitor on the power supply.

the +5 volts gets its supply from the +12 volts so i doubt its the bridge.

there is one more test you can try. with the dmd and controller connected
Black lead to gnd
Red lead to the left side of R6 (the big white resistor under the heat sink)
Then Red lead to the right side of R6

if both tests show 0.** volts then the fault is in the power supply
if one test shows +5v and the other shows 0.** volts then the fault is on the dmd driver board

But going back to what i said at the top of this post 4.83V is to low at the power supply so you need to sort that out 

 

thanks for the guide, I did the test with the following results:

no plugs to the dmd - white resistor
lhs = 4.83v  ,  rhs = 5.05v

with just the dmd lead in - white resistor
lhs = 0.39v  ,  rhs = 0.55v

with just the dmd board lead in - white resistor
lhs = 0.06v  ,  rhs = 0.19v

with both dmd & dmd board leads in - white resistor
lhs = 0.06v  ,  rhs = 0.18v


so based on that it looks like a power supply issue   

does that mean the power board ????