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Flash lamps sticking on

JWG9999

JWG9999

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10 Years
Joined
Apr 15, 2013
Messages
670
Location
Yelverton, Devon
The 3 flash lamps in the skull on my Hook have started to stick on. In test mode they switch on if I flash any of the playfield inserts, once on they stick on.

It appears they have a single driving transistor which I haven't identified in the MPU board yet but in any case I'm not sure that's what I should be looking at.

I'm ploughing through the manual but I'm finding it hard to understand how the MPU / PPB boards work together for the flasher circuits.

Can anybody offer advice for this problem please?
 
Have you found this on Page 29 - I'd be checking CPU Q26, PPB R11 first. Four sets of inserts shown all have the same feed orange cable PPB J6 4/5 perhaps this is relevant? This part confuses me a bit as these lamps aren't on the L/R relay switched with the Solenoids as most of the flashers are.

upload_2015-4-28_18-34-51.png
 
Thanks for that. I'll certainly look at Q26 and PPB R11. Right now I don't understand the above circuit diagram (are the long blocks either side of R-11 and R-12 simply IO connectors? If so, does that mean the only thing the PPB adds to the flasher circuit is a resistor?) I hope that when I compare it to the physical board it will make sense
 
JWG9999 said:
are the long blocks either side of R-11 and R-12 simply IO connectors?
Click to expand...

Yer, so the path is

CPU Q26 -> CPU CN12-6 -> PPB J1-12 -> PPB R11 -> PPB J9-15 -> Skull lamps -> PSU J6-4/5

I'll check that further as some of these ipdb scans are hard to read.

I'm not an expert but logically would be checking that path first.
 
Those last two posts are a lot of help actually. You've clarified it for me a bit. I think I'll blank out CN12-6 and see what happens. If skull flashers stay off then I must assume the transistor is being switched on and held on by the MPU logic. I hope not!

If, however, problem persists even with CN12-6 disconnected then I've got some sort of cross-talk with other circuits.

I've got a horrible feeling I do need a new MPU circa £250, there's one or two oddities starting to show on this machine. It really has been a bad buy :(
 
astyy said:
Basically, does the right bank bottom target light when you start a game?
Click to expand...

Ooops, sorry I missed that one.

The answer is Yes, sort of. It doesn't light until the ball 1 is launched, then it lights straight away. Hook gives you a light towards your first multi-ball for each ball launched.
 
Have replaced Q26 and it's now working again.

Thank you to all who helped here

Sadly my soldering is so bad I know I'm ruining the board even though it usually all works in the end, I hate touching the boards.

And the MPU is pretty suspect anyway: hi-score logic isn't working properly, game logic now sometimes goes haywire, e.g. an extra ball appearing in the shooter lane for no good reason. Doesn't happen often, but it happens. Plus that's the second transistor has failed in one week. Something just ain't right.
 
JWG9999 said:
Have replaced Q26 and it's now working again.

Thank you to all who helped here

Sadly my soldering is so bad I know I'm ruining the board even though it usually all works in the end, I hate touching the boards.

And the MPU is pretty suspect anyway: hi-score logic isn't working properly, game logic now sometimes goes haywire, e.g. an extra ball appearing in the shooter lane for no good reason. Doesn't happen often, but it happens. Plus that's the second transistor has failed in one week. Something just ain't right.
Click to expand...
Extra ball in shooter lane could simply be flaky switch in trough or whereever
 
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