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UT62256PC-70LL are standard 256k by 8-bit 70ns RAM chips. Should be some or an equivalent on eBay. Here you go.... https://www.ebay.co.uk/itm/296374652026 No idea if they're genuine or not, you have to take pot luck with that kind of thing on eBay these days. For the sake of £19 it's got to be wort a try? Just make sure you put them the right way up and at the bottom of the socket with the empty four holes at the top.

hi looking for the mpu6 exec file for t8 think it starts t888.2.????? cheers toddy

ok , dont they need to be astra classic slot bar top ones so the work on my machine?? if so i will have to be very lucky..

Not necessarily, you could probably buy the RAM chips off eBay just make sure it's a reputable seller and not some cheap shit from China.

Ok thank you ,so end of the Bartop then

in this pic BOTH your rams are the wrong way round! IF..... you insert the ROM the wrong way round it will instantly blow with no chance of data recovery, so as they say with cutting wood, measure twice cut once! so check twice, ...... then check again BEFORE ever applying power! electronics likes to blow if not done correctly

Many thanks...

The one you put in upside down is definitely fucked. Don't worry, we've all done it...

Thank you for the fantastic layout.

All i get now is a red and green light on the board and nothing else so do you think the ram chips are burnt out???

Yes its looking that way

Probably because you put one of the RAM chips in upside down and cooked it

Big shout out to Peter Falconer aka "Magik" for his continued and invaluable assistance in repairing my broken mpu boards. Peter has talked me through repairing a couple of mpu boards and I really couldn't have fixed them without his awesome knowledge. He has a YouTube channel with videos of his repairs - well worth a look:

I found a photo of my board in the end and tried everything and it still does not work ive even put the old board back in and thats dead now so i think ive broke it so im going to leave it for now , thanks for all your help

Here's my working spare board. Your right chip is upside down.

Just placed the original ones on the old board as you can see these are smaller

The ram chips on the original board are slightly smaller than the new board ones ,,, any chance you could take a photo of yours please from your machine if you dont mind as now ive took them off im unsure of the position and which way round the should go now!! i know i should have took a photo before i took them off

Everything you said looks correct so maybe ive been sold a faulty board , i will check all the connections again just incase

I think the RAM chips are standard. Make sure all the jumpers and switches are set the same as the old board. Also make sure it is fitted with the same number FPGA chip (the one with "ACTEL" and a sticker on it). If not, you will have to use an extractor tool to get the old chip out and transfer it to the new board.

Hi , Ive got a board of EBay has anyone who has this machine can confirm I’ve got everything in correct please ??? As it’s just dead nothing is happening , also the black u3 ram and black u4 ram should I have swapped the ones from the original board please ?

Thanks I have used Arkaid before so will contact them again.

Hi, Yes MPU board fault, most probably a triac gone or a faulty 6821 pia ic. By swapping the the MPU`S you have at least eliminated any thing else.

Hi all, I have an old barcrest mpu4 machine that has stopped paying out 10p's. Had this before and was a blown fuse in the power supply however have swapped power supplies with a working g one and the fault is still there. I have swapped the mpu4 board and the machine is now paying out. The battery has been flywired for years. Is it a case of getting the board tested and repaired or does anyone have any other experience with this issue. Many thanks in advance.

I've just realised, I forgot to post the sound ROM for the Rol-a-top. So here it is. Cheers, Paul M27C4001@DIP32.BIN

No, that'll do you no good at all for MPU3 AMP crimps. I did do a thread on this ages ago if you can find it. I did make a three pronged tool which worked pretty well. The official one is really expensive although it is still obtainable, probably because no one has bought any. The part number is :- 455822-1 but it's over a £100 !!!! I found the easiest method was to use two small jewellers screwdrivers and turn the crimp in the housing until the split in the crimp is in between two of the slots in the plug. Insert the two screwdriver blades either side and then pull the crimp out. It should come out fairly easy but don't force it as if you mishape the crimp you'll never get it out!