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We have all done it Ronnie! Many times, glad you got there 👏

Sorry to post another one ! But I’m stuck again! This one was working last year but had a lamp issue and a locked on payout solenoid, so I hooked it back up today and it sticks on resetting in the alpha! I swapped out the ram and anything else crusty or green was previously replaced in the battery area etc, also the caps on the voltage regulator were replaced. Not sure where to start checking? Ram volts are all good. Could this be a problem in the reset area? thanks for any help cheers Ronnie

So just an update on this ! I decided to check for reel voltage and I had none tracing it all the way back to the big diode I was confused why I had no power then I realised I fitted the p600 diode the wrong way round! Must have been a senior moment! Spent blood ages on this one, oh well at least it’s working now thanks Ronnie

You could try asking on the UKVAC forum. Some friendly person on there may have one... https://www.facebook.com/groups/ukvac/?ref=share

I doubt you will be able to get one of those these days,, I think there was a thread on them awhile ago ,, 🤔

Hello friends. I'm looking for a 35-pin header for my JPM 9980 SRU controller. Does anyone know the order number? Thank you.

So Powered it on this morning fired straight up, instantly out of reset and booted! Surely it's not self healed! It seems since I scoped the 541 it has worked! Now if these mpu3's could only self heal!

been there and got the proverbial T-shirt. It can be a real pain when that happens. Still if it's working, it's working!

Still running and playing Bob! Have played it on and off and switched it off and on, won’t die! Weird!

Thanks Bob the reels are limp not energised will check pin 12 tomorrow

I thought there should have been a pulse on 13?? I don't have my notes to hand to confirm and I'll be away for a couple of days but will check on my return. It's funny how it's stayed on though. It's doubtful if there would be any dry joints on that chip as MPS2 is pretty good in that respect.

Those parts are used in the 100Hz feed for various functions, which goes into IC18, so make sure you have a good square pulse on pin 12. If the reel volts were missing they would be easy to turn manually without any force.

So since I done this the machine has stayed on without any nonsense, must have been on 3 hours plus

Thanks Bob, yes 576 Hz I also just swapped out the discreets round the power plug, 3 resistors a diode and a tant they were a bit green legged, I'm just wondering if I'm missing the reel volts?

Then when reset goes out I get this on 11 to 14

So before reset kicks in I get this on the 4 outputs

Hmm, lots of head scratching going on this end. This has probably nothing to do with it but can you check the o/p from the 555 (3). It should measure between 500-660 Hz.

The chip does but IC20 only uses 4 so it's pins 11, 12, 13 and 14

Yes I had already resoldered both plug pins, I also swapped out IC9 as it was already in a socket but still no reel twitch

I think the 541 has 8 outputs? Which 4 am I probing? This was pin 11

Thanks Bob, I will check the outputs with the scope but will order one anyway

It is mainly the RESET but before we go down the rabbit hole it might be a good idea to swap it out. If you can scope the 4 outputs from this chip and they look OK then maybe all is well. Like all these things that are intermittent sometimes it's best just to swap out to be sure, at least it's another thing eliminated. The part number for the TVS is 1.5KE6.8A (RS 171-9442)

Thanks Bob, is the 541 likely to cause this issue or is it only to do with reset?

I grew up on Ihe island but that place wasn't there until after I left. Did visit a few times in the 2000s when I went back to the Island for holidays.

Sorry I meant the 541. I do swap out the TVS's on these boards as they do go short sometimes unless they look like new of course. The TVS is like a zener and shorts out the supply line if it goes above 6v. I don't have the part number handy I'm afraid.