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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.

Thanks Bob, I did look at them sure they looked ok but will double check

Sorry if I've already said this but I'm rushing through my inbox trying to clear everything. Can you make sure there's no solder rings on the green connector. Might go for the red one too.

Thanks Bob, is it enything specific? Is TVS what to search for https://www.ebay.co.uk/itm/225089479082?_skw=tvs+diode&itmmeta=01JXQMKZ8SQ1E2JEQX9HC7W2N7&hash=item346860e1aa:g:O4wAAOSwsw1h8VRk&itmprp=enc%3AAQAKAAAA4FkggFvd1GGDu0w3yXCmi1cxyhFO%2F1aDHF2zAnXF2i7jViS2o9N70h1eso7%2Bw7j1SS78LiivFJUeks5VfLZR%2Bi0R8w0CViOIkQVRVaFUAnYrvKDBElVkfll9kVbOlhgCN%2FLNwAvbnSTzvyZpKl7VzDtWJWCzOnaF%2FEYskEuQu3CI%2BkjHexrVseEwC%2BYu1saz73Nz8dp5i2Zp6w76cCSlvLf06BONd1XxAwoFdWq88dujTx8tue9yQNl871sgEXjOoKVbTiE1NhDT5uKOYN5VltCwhKSEtZLQPw37ABabXch0|tkp%3ABFBMyvTP9O1l

I would swap it out anyway as that one suffers the most being next to the battery.

I tried to piggy back IC5 but no change! Not sure what to check next, this board was fully working until it had a reset fault now this.

Thanks Bob I’m getting a good 5.1v across tvs1 it’s weird after a long while to come out of reset this morning I was able to play 20 credits before it started messing about! I guess I need to change the 541, here is a pic of the battery area

You'd also better check for voltage starvation across TVS1 (next to the CPU). Should be 5v or thereabouts. If the PSU connector pins are dirty or lost tension it can drop below 4.7v and all funny things start happening.

I loved going in there, sadly missed.

easy one

So I replaced BC138 and changed the cpu socket, it had no signs or rot or green under, nothing really has changed! It sometimes boots but not for long mostly hangs with bottom left seg lit Thanks Ronnie

So yes the reel lamps light at which point it alarms

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