ZX Spectrum Harlequin rev. G problem

[shadow338]

Hello all,

I recently bought an zx spectrum Harlequin kit (rev G) which I happily assembled.

I checked and double checked all connections and components but the computer is not working as expected.

I'm not sure if I did something wrong or not but I'm not getting the proper prompt on the screen as you can see on the video link.

It basically shows some weird screen and then it monitor turns off.

I'm lost with this. If anyone could point me on the right direction of if someone knows if there is any dedicated forums for harlequin issues or related matters I really appreciate.

The board after assembled:
http://postimg.org/image/odwsyuib1/

Video showing symptoms:
https://www.youtube.com/watch?v=7PQNmLd6lZo


Many thanks.

[1024MAK]

Is this the same one that is being discussed on WoS?

Mark

[Fwapp]

OK - jumpers circled in RED - REMOVE THESE - one set is for supplying -5, -12v to the PCB, the other is for access to the +5v and +12v on the PCB. You do NOT want to short these out.

Jumper circled in blue - think this is for ROM image select - use the jumper to short pins 1-2 or 2-3 together - in the image neither is.

Jumpers circled in purple - these select PAL/NTSC - looks like only one of the three sets is set - ensure that pins 2-3 are selected on all three sets of jumpers. Not sure which pins are 2-3, so you may have to try all three jumpers on the other set of pins.

I built Ben Versteeg's version of the Harlequin recently, but that PCB looks identical in layout.

[shadow338]

Fwapp,

holy damn that worked and I now see the banner "Sinclair Research Ltd".

So the jumpers in red circles had jumpers but nothing was selected (I was lucky here then, nothing broken)

the blue circle jumper was not selecting any ROM like you pointed out.

and on the purple circle jumpers I was missing two jumpers.

So now my last question and thanks a bunch for the quick fix:

My kit came with a 4.43MHz crystal, so that means I'm stuck with PAL or I can still select NTSC?

Also, I'm not using a TV, I'm using a small monitor that says that is capable of doing both. Does it manner in this case then whatever I select here?

Thanks.

[Fwapp]

Glad its working

When I select NTSC on my Harlequin, the picture rolls, which is as I expect. You can try it on yours, it certainly won't hurt anything, and I don't think it relies on the crystals.

[-B-]

You need a different crystal for NTSC 3.58MHz
-B-

[1024MAK]

Well done

Is this the same one that is being discussed on WoS?

Apparently not. For reference, the thread about how another Harlequin Rev. G board is here

Mark

[shadow338]

One thing I noticed is I'm not getting any sound from the tiny speaker.

I swapped the tiny and fragile speaker that came with the kit and installed one from an original ZX spectrum board but I still don't get any sound.

I tested the speaker and it is in good working order.

Does anyone knows the purpose of J15? I currently don't have any jumper on it.

Any ideas?


thanks!

[1024MAK]

You need a link/jumper shunt on pins 1 and 2 of J15 to enable the on board speaker. Or you can attach a three pin wire socket here, then pin 1 is audio out, pin 3 is 0V/GND/Ground. The levels here are NOT "line" level though.

Mark

[shadow338]

that worked. thanks!