Hi everyone.
I recently picked up an MP1 off BookFace the other day with the known issue that the picture was "A bit rubbish". Truth be told, the picture is a lot rubbish and after some searching, I found Bryce's thread http://www.cpcwiki.eu/index.php/LCD_And_Plasma_TV_Solution (http://www.cpcwiki.eu/index.php/LCD_And_Plasma_TV_Solution) on composite modding.
I have one question about it (Mainly aimed at Bryce as it's his mod, but if anyone has done this before, you might be able to help me out). If I were to disconnect the coax from the RF unit inside the MP1 and chop the end off, could I then strip back the insulation and solder the respective cables to the points mentioned below?
(http://www.cpcwiki.eu/imgs/c/c7/MP2_Under_PCB.png)
Could I then remove aforementioned RF box as I'll never use it again?
Thanks in advance.
Yes, the points in the picture are the inputs to the HF module. If you are taking a composite signal from here, then the module is doing nothing and can be removed (if you don't intend using it again).
Bryce.
Cheers Bryce, that's the answer I was hoping for.
Try to remove the modulator without damage and don't scrap it. It's an Astex UM1804. A useful little modulator used in many devices.
Bryce.
Eeeeeehhhhh............It kind of worked.
Thinking I could keep with original feel of the unit, I chopped the TV end off the cable, stripped it back and soldered it on. Plugged the RCA end into a spare composite slot on the TV aaaaannnnndddd blank screen.
Thought I'd cocked it up at first but after wiggling the cable near the connector end, it gives me a very trashy blue screen with bits of yellow on it. Given the amount of crud I scraped off the wires before I tinned them, I'd say the cable is way too old so I'll replace it when I find a new one.
Good job I read your last reply, I'd already binned the RF module :picard: . It's now been rescued and is now safely in my parts box.
Thanks again for your help, Bryce. I'll let you know how it turns out in take 2.
That old wire probably has 20 breaks and cracks in it, definitely replace it with a decent wire.
Bryce.
You're not wrong mate. I've decided to replace the cable and din connector. Only problem is, the wires snapped clean off the solder points when breaking open the old din connector. I don't suppose you'd know which colour wire went to what pin? The only info I can find is for wiring to a scart connector which leaves out the yellow wire.
The whole schematic is here: http://www.cpcwiki.eu/imgs/2/21/MP2_Schematic_1.PNG
You can see where each pin in the DIN connector needs to go.
Bryce.
Success!! It lives!
Had to fiddle with the variable cap as the picture seemed to buzz in tune with the transformer.
One thing I have noticed is the whole screen isn't displayed until you print text all the way down. If you press return more than 6 times though, a black bar appears until you start printing text again.
I tried loading a game but I have no idea where my HxC is and the tape drive belt seems to be kaput ::) .
Might as well order some floppy drive belts too while I'm at it.
That effect with the black bar isn't something the modulator could do. It sounds like you have issues with either the Gate array or the CRTC Chip.
Bryce.
Quote from: Bryce on 08:10, 04 April 17
That effect with the black bar isn't something the modulator could do. It sounds like you have issues with either the Gate array or the CRTC Chip.
Bryce.
The black bar is probably the vblank normally triggered by vsync.
On the CPC monitor the screen can be adjusted with the vhold, not sure what is needed on mp1.
It could be:
- a dodgy link on the PCB causing it use 60hz instead of 50hz. Does it change when you run a game?
- the sync is going from the crtc to the gate-array, could be either a problem with crtc, or gate-array or a bad connection on the video out of the cpc.
Hi Arnold,
Like I said, I tried to run a game but the tape drive belt is a bit sloppy and I can't find my HxC anywhere in the loft.
I would say the wiring is at fault as I wasn't at my workbench when I replaced the cable to the MP1 (I was sat on the living room floor), and until I can run a game, I can't specify further.
Thank you both for your inputs though :)
Arnold,
I've managed to get the tape drive working and I get this
(http://i65.tinypic.com/33v13r7.jpg)
But when I select play and cut to the game, I get this
(http://i67.tinypic.com/2ngwghv.jpg)
The bottom half of the screen disappears. I do have a scart cable somewhere, which I'm trying to find so I can eliminate the CPC so watch this space..............