Merlin Tontos

[RWAP]

I have 3 Merlin Tonto computers here - someone is coming to pick one up on Thursday, so there I was happily testing it - left it switched on and went away whilst it was copying some cartridges (onto ones with new felt pads), when I start hearing the dreaded popping and turn to see smoke pouring out of the monitor....

Robin Williams may have loved the smell of napalm in a morning, but crikey, the smoke from one capacitor is enough to make you run for the hills.

This is about the third OPD / Merlin Tonto monitor I have had go up in smoke - typically it seems to be when the monitor goes to sleep. It does seem to be a major design fault in the mono monitors.

Luckily the monitor can sit outside for a couple of hours to let the smoke dissipate....



Whilst on the subject - does anyone have any ICL / Tonto BASIC cartridges - I can't read either of the ones I have here. I have some copies on disk, but no teledrive unfortunately. I know Dan Abbott is the best person to contact, but he has not responded to recent emails....

[1024MAK]

Are the self smoking capacitors class X or X2 type made by Rifa by any chance?
If yes, this is well known... See here for example. Or ask Acorn BBC micro owners...

Mark

[RWAP]

Darn it - yes it is an X capacitor now I've opened the casing.... - 0.1uF

Just need to find a replacement now... (and leave it outside to let the smoke dissipate some more)...

Any ideas on a replacement

[1024MAK]

Any modern X2 type (must be marked "X2") that has the same lead pitch will be okay. Also check the physical size, as different capacitors from different manufacturers may not fit on the board if the original was a Rifa and it is close to other components. Note that Rifa capacitors are still available, they are made by KEMET.

Buy from a proper supplier (you have to be careful, X2 capacitors have to comply with with various safety ratings, and with some sellers you never know what you are getting if you buy from some auction sites).

Scroll down to the 100nF order code 867-061 from ESR
Rapid have various makes: Suntan, Suntan mini, TDK, Vishay, Wima
CPC's range
Farnell have a wide range
As does RS
There are of course other suppliers. I have used all of the above suppliers.

Always double check that the capacitor is a "X2" type, as sometimes the search results pick up other types.

Mark

[vanpeebles]

I'd love one of these old beasts if I ever get enough space. Would it be possible to fit a tft screen inside the housing instead of the crt?

[RWAP]

Possibly - you have to remember that the monitor is used to power the Merlin Tonto / OPD - I now have 4 working Tonto's, one working monitor, one monitor that needs a new x2 capacitor, and one monitor that probably needs a new capacitor (the power flickers on and off and eventually the Tonto springs into life)...

[Derek_Stewart]

Hi Rich,

I have a couple of 12v TFT Monitors, maybe this could be used to replace the CRT. I suppose a Jamma board could be fitted inside the Case and any VGA monitor could be used.

Pity you were not going to the AGM, we could of tried that there.