Hi, my uncle brought me an old Sony HB-F700S(spanish). It's a MSX2 with 2 cartridge slots and one disk drive. He brought me only the CPU, no video cables, no keyboard, no mouse. It has two video outputs, one RGB(color) and one video/audio(white/black). The RGB connector is a 8 pin DIN and the Video connector is a 6 pin DIN. I have bought the connectors and made two video cables: 8 pin DIN to SCART and 6 pin DIN to RCA. When I switch on the computer, the power led turns on, and it tries to load from the disk drive, because the disk drive led also turns on, but I can only see a blue screen and can't hear anything. I cannot hear any sound from inside the CPU, the disk drive doesn't make any sound. When I load a cartridge, the power led turns on, but the disk drive led doesn't turn on. I have downloaded dsk images(hibrid) and have written it to disk, and when it tries to load the disk, it sounds like when the disk is bad(ssssshshshshshsh). When I switch on the computer, the TV shows a blue screen. I think that the BIOS is OK, because the computer tries to load disk. It also seems to give some video output, because the TV reacts when I switch on the computer, but I only have the blue screen. Any clues?

on a msx2 you should see the msx2 logo on the blue screen; before the disk drive goes on. check your cable or try (if available) with the rf modulator with a standard antenna tv input.
If after a short period the disk active led shutdown, we can say that the vdp it's working, the interrupts are generated and the cpu is running.

Please, first be sure that the blue screen is not from TV's OSD chip display that block the NO-SIGNAL video. Setup the TV turning OFF the blue screen on not signal status. So in that way if you set a no-signal channel, you can see the rain (noice), or in video input you can see the black screen.

Then turn on the MSX.....

Are you sure you can do something without keyboard?

Hello,

There are modified HB-F700S (one jump over a resistor) that was necessary for RF adaptor (SVI). Maybe you must remove the jumper solded over the resistance. Just guessing.

Greetings

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Please, first be sure that the blue screen is not from TV's OSD chip display that block the NO-SIGNAL video. Setup the TV turning OFF the blue screen on not signal status. So in that way if you set a no-signal channel, you can see the rain (noice), or in video input you can see the black screen. Then turn on the MSX.....

I have tried on my LCD TV. When I switch on the MSX, the TV changes to the video input, but now I see a black screen, no MSX2 logo.

Any ideas?

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I have bought the connectors and made two video cables: 8 pin DIN to SCART and 6 pin DIN to RCA.

Do you use the proper schematics?

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When I switch on the computer, the power led turns on, and it tries to load from the disk drive, because the disk drive led also turns on,

This is usual, because the computer is checking the units...

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but I can only see a blue screen and can't hear anything. I cannot hear any sound from inside the CPU, the disk drive doesn't make any sound. When I load a cartridge, the power led turns on, but the disk drive led doesn't turn on.

There are no fans inside MSX, so it's right to "hear silence" When you insert a cartrige, the system is overrided and there is no access to the floppy (so, no sound or light from it)

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I have downloaded dsk images(hibrid) and have written it to disk, and when it tries to load the disk, it sounds like when the disk is bad(ssssshshshshshsh).

It's very difficult to access the drives without keyboard...

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I think that the BIOS is OK, because the computer tries to load disk.

This is only if the disk has any kind of "autoexec.bat" (MSX-DOS) or autorun (like some games on diskette format)...

I think you need to check the RGB-Scart connector. Maybe it's something wrong with it

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Do you use the proper schematics?

Yes, I have found them in MSXFAQ.
I'll try to check the connections or buy a proper cable.

I think your cable is wrong.

There are several schematics for "Japanese RGB", but pinout is slightly different in some models.

First, in the DIN-8, you should try with a voltimeter to find VCC. Then just solder GND and then try with every other pin (except VCC) to connect to CVBS (COMPOSITE). This way you will identify every pin and will not damage your TV set.

RF antenna cable is another option