YAMAHA MAGICSTOMP PROBLEM

[bobbybond]

Hi, my Yamaha Magicstomp has packed up on me. All I get now on power up is a lit screen with a few rectangles that soon fade away, leaving a blank lit screen and no sound.
Does anyone know of someone who could fix this problem please? From what I've read, it seems too tricky a job for me to replace the screen.
Any help would be much appreciated.
Kind regards
Bob

[davec]

Hi Bob,

Your screen (and it's logic controller) has failed, probably because of overheating. The base of the MagicStomp acts as a very crude heatsink and, if you use it on a carpet, it is almost totally ineffective. Those tiny rubber feet need a bit of clearance (e.g. on a hard surface).

Get a replacement screen from:

http://www.ebay.com/itm/200659769398 and be sure to specify Y/YG. The old obsolete 162s are a straight replacement: the more modern 1602s may need added resistors to the power supply (pins 1 and 2), the contrast (pin 3) and the backlight (pins 15 and 16).

This is the replacement process:

http://www.worldwideshadowsmusic.com/vi ... =87&t=4182

You, or whoever you get to do the job, will need a solder-sucker or loads of solder-removing tape, some good old-fashioned (non EC-approved) lead solder -- and patience. Removing the old solder from 16 pins is not difficult but it's a slow process if you don't want to cause further overheat damage. You may need to do a little bit of filing around the aperture because the screen surrounds do vary in size.

Have a look at this thread:

http://charliehall.proboards.com/thread ... ay-failure

Regards,
DaveC.

[bobbybond]

Hi Dave,
Thank you for your comprehensive and very helpful reply.
Would you know of anyone who could carry out a screen replacement for me please? I'd hate to make a pig's ear of it and would be happy to pay a reasonable price to have it done.
Kind regards
Bob

[davec]

Hi Bob,

Barry Knapp (aka barryk) in Glos. was offering to do this. I don't know if his offer is still open, but remember that there's quite a lot of work involved -- so be generous! Also Amanda Hambidge (aka valvewhiz) might be able to help. I think that you would have to supply the replacement 162.

Regards,
DaveC.

[bobbybond]

Thanks very much for this information Dave.

Do you think this display screen from RS Components would fit the bill: http://uk.rs-online.com/web/p/products/5326379/

Best regards
Bob

[davec]

Hi Bob,

The unit from RS is described as a 162 rather than a 1602 so you shouldn't have to tweak the supply voltage or contrast, but I'm not sure whether the screen surround matches the existing dimensions. Time to get your measuring stick out and read the data sheet! Try to minimize the filing you have to do.

I didn't know that anyone in the UK still supplied 162s so check with RS that it is what you are getting.

If I were you I'd order one of those Chinese ones anyway. It'll take about a month to arrive but, for a fiver, you'll have another option if the RS is no good.

Regards,
DaveC

[bobbybond]

Many thanks again Dave, I've ordered the Chinese screen, as you suggested.
Best regards
Bob

[davec]

Reading through posts on other sites it's seems that some people have trouble removing the old daughter-board.

I may be teaching all the grannies here to suck eggs -- but I think it's worth pointing out the old trick of removing solder by adding solder!

Strange as it sounds, if you apply a small amount of lead solder (with flux) to the tip of the iron and then touch it to the joint, the heat transfers faster and the flux makes everything flow easier. Immediately the joint liquefies, hit it with the sucker or tape. Everything should clear in one go.

Do this one pin at a time and let everything cool down in between.

DaveC