Speccy+ - Buzz and reset

[sten969]

Hi all,

I hope you might be able to throw some info my way on this problem. I recently purchased a "for spares or repair" spectrum+ to use it as a case donor for the Next. Problem is, now I've cleaned it up and replaced the membrane and keys etc I don't really want to cut into it. I've had a few answers from the Spectrum Next FB group but thought to throw it open here too. In a nutshell it's an issue 4b board which displays fine but when I press any key not on the top row the speaker buzzes and the machine resets. Any thoughts would be much appreciated.

Many thanks,
Steve

[rwap_software]

It puzzled me for quite a while when I first came across this issue - thankfully, the answer is normally fairly simple.

The answer is normally one of two things:

a) When you press a key on the top row, the membrane tails are shorting across the TV modulator. Sinclair normally added a bit of felt on top of the modulator box to prevent this. You can use some insulating tape, or one of the small rubber feet we supply.

b) If you have a Spectrum where the heatsink runs along the back of the Spectrum (rather than down the side), then the key presses could either be causing the membrane to short across the heatsink (again add something to insulate the end of the heatsink), or (more likely), the power regulator needs to be resoldered (or the bolt connecting it to the heatsink is loose), so that pressure on the heatsink moves the regulator and breaks the contact with the PCB, or it allows the regulator to overheat