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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

Vintage 1970s/80s Original Fruit Machine Glass Panel - Man Cave - Bar etc.. | eBay UK

I don’t think they do bob but I will need to double check that tomorrow

I can't remember if I asked this but do the reel sensor lamps fire up? They should all come on together.

Just got back to this board today, so hooked up to the machine it reports a reel B error. On the bench only psu, alpha and cart it reports reel A, I know the reel deck is fine in the machine So Bob I checked IC5 pins 10-14 but it's alarming reel A as I probe the pins, all 4 pins are floating! I reset the board whilst probing pin 11 it never gets anything right up to the point of alarming? Edit, I just did the same test on another board and the results were the same as above, also it's now showing reel A when connected to a machine but no reel twitch it goes straight to alarm Thanks Ronnie

I'd stick to the existing type ie 74LS541 or even 74ALS541. I know there are some minor differences with the CMOS types (HC) that may (or may not) cause a problem.

Thanks Bob, for IC20 is a 74HC541 suitable? I have some of those and will order BC183's

Found this. Wish I had a time machine...

Even though most of it isn't my tech (and all of it goes over my head), I absolutely love reading your posts Bob.

Yep always good to swap out those three transistors. If it takes a long time for the reset LED to go out it's possibly IC20 that's going bad. Any of those 4 IC's surrounding the CPU all suffer due to the battry.

Thanks Bob, no not smelling it was a brief coating then good wash off ipa scrub and a good blow off with compressor I did change the 3 caps in the sound section and it did improve but still not right, the straw did trigger the sound to come back, now the board takes a fair time to come out of reset and Mostly sits with bottom left seg lit. I may change the cpu socket just to be sure, also the the B138 I think it is ? Has green on the legs so I need to source one of them , I changed the other 2 ZTX transistors before because I had them thanks Ronnie