Robotron ROM PCB Failed?

[Robotgreg]

I was reseating connectors in the hope to fix a problem with no green on the game and now no response from the main ROM board on Robotron.

I'm pretty sure when I reseated the power connector on this pcb that I put it on the wrong way round initially but when I put it back on correctly as I say nothing comes up and the 0 led display on the board does not light up at all.

I've checked and getting 5V on the connector so thinkng I have bust the ROM pcb by connecting the lead the wrong way round.

I've put a pic below in case anyone can see if anything looks obviosuly blown.

I can swap the ROM pcb with Joust both ways but wondering firstly if anything will come on with the Robotron ROM pcb in Joust (as I'm not expecting anything to happen assuming it is now broken) and secondly if I risk blowing the Joust pcb by putting it in Robotron , if it is not due to connecting the wrong way round and instead the power supply is duff. I'm thinking this is unlikley given it worked fine before I reseated all the connectors and the 5V (5.07) is good.

Thanks for any advice

Greg

 

[philmurr]

If you connected the power the wrong way round it would have blown a fuse as you'd have shorted out the power supply.

Can you measure the 5V with the ROM board connected? Also try reseating the ribbon cable where it connects to the CPU board as they cause loads of problems.

You can swap Joust/Robotron ROM boards without issue and the relevant game should boot up, although obviously the controls won't work. Also you will lose any saved high scores if you do this.

 

[Robotgreg]

Many thanks, Phil.

I did wonder about a fuse but then thought if I'm still getting 5V at the power connector then logically should be OK. Anyway you're right, a fuse had gone - F3 in the pic below (fuse removed). Replaced but sadly it blows on start up so wonder if something on the power supply has gone.

Other two fuses are OK.

Still get 5V when connected (5.01).

I had bent some pins on the ribon cable connector but have rebent back so hopefully OK now unless that's what causing the fuse to blow?

Checked ROM pcb in Joust and it works fine so looks like power supply. Does anything look suspect on the board or anything else to check (bearing in mind I'm not very technical).

Many thanks

Greg

Robotgreg2023-02-08 14:11:05