I've acquired 4 MSXes recently and I am seeking some help to make them work properly... it seems I did not make a great purchase here ...

1/2) Sanyo PHC-28L and Sanyo PHC-28S
Both only start-up in B/W ... using them on a colour Monitor with RCA-RCA or RGB-RCA plugs with same result... same with RCA-SCART to modern TV configuration.
all my other MSX1's and MSX2's work perfectly in colour with this configuration (VG-8020; HB-75F, AX-170, AX-370...) - or is maybe again the French having different standards for their computers? (ndrl, both Sanyo's are 'French').

3) Sony HB-700F
Only RGB output on back, gives a very very weak Black & White signal, same on Monitor or TV... the machine seems to work properly except you hardly can see the image... what could I do???

4) Philips VG-8235
Got broken near the power switch during shipping. When looking at it, nothing except the plastic of the case seems broken... but of course, MSX would not even power on... can you help?

Thanks
Phil

I'm sorry, I can't really help you, but I can confirm that the PHC-28L gives color image on a Philips monitor. I'm using a simple RF cable.

French TV standard is SECAM, not PAL. That could maybe be the problem, however most european TV's support both standards.

I don't believe this is the problem... my TV was bought in Belgium (so should support SECAM) and supports NTSC as well (at least I have colour on my WSX and Turbo-R's...)

How much trust do you place in the seller ?
I mean, did you buy from him before ? Did it go well then ?
Maybe you can send them back to him and ask your money back ?
I wouldn't be very pleased if I bought some MSX's and got broken machines...

Anyway, I'm pretty sure the problem is not your TV or monitor

First time buying from him - was a full lot with MSX stuff and I know he won't pay back anyway, I'm seeking a solution to repair them... anybody?

contact Bas Kornalijnslijper (baskornalijnslijper@zonnet.nl) who can probably identify the problems

Just done, I'll report back if a solution is found. Thanks.

Maybe 'Set screen' was used to boot in black and white?

I have a VG8235 on which I changed the VDP for MSX2+ .

Then I got very weak signal.
I took a look to technical doc of VG8235 on HansO site
and found that the video scheme was not the same on every
model ( espicially french vs German , and I bought it in germany
to use it in france ).
I did some changes I then it works fine.

Before the VDP change, it was working fine.

I have the same problem on a SVI-738 which can connect
only by antenna , on my PAL-secam TV and it is B/w ...

Quote:

Maybe 'Set screen' was used to boot in black and white?

This did not work still trying to fix this... thank you again already for all your suggestions.

Quote:

I have a VG8235 on which I changed the VDP for MSX2+ . Then I got very weak signal. I took a look to technical doc of VG8235 on HansO site and found that the video scheme was not the same on every model ( espicially french vs German , and I bought it in germany to use it in france ). I did some changes I then it works fine.

Leo what changes did you make to get the video signal OK again?
I upraded my 8250 to 2+ and lost colour on composite (looks like weak signal) and would like to repair it.

How is the IDE for msx1 comming?

jpgrobler@hotmail.com

On MSX logo (White over black) the white was rather looking Yellow,

I remove keyboard
I tied pin 6 of V9958 to a resistor R13 under the video card which
has printer,antenna,RGB connector.

On the PCB , you R13 written an then 6 six resistor in parallel below.
Take the top one just under R13 label.
The pin on the right should be unsoldered and tied to pin 6 of VDP.

I have an other VG8235 which PCB is completly different , I guess
most of the TTL logic have been gathered into specific circuits. And ROMs
have been merged in smaller. Dont know which version you have ?
So it is much smaller , but I dont have the technical documentation
of this one.

You did the change of VDP ?
Have you noticed the picture seems shifted to the left as compared to
V9938 ? I use set adjust (8,0) to get it centered.

Did you make the ROM upgrade ? I bought a 1Mbit flash I recorded with
the IDE interface with some MSX2+ bios , but I am still waiting to have
some time to put it inside instead of the 3 roms ...

IDE for MSX1 , I have not touched it since last time ...lack of time...
But today I have some time !!!

Leo

For the HB700:

I remember I got an HB500 which had a lot of problems of false contacts
on the RGB connector I had to redo soldering twice ...

Think , most of the failure should be mechanical ( cord , connector , false contact )
Any way this is what should be checked first.

I have a HB700 that I got off ebay - I made a self bulid RGB cable, and it had a black and white picture that was distorted. I thought maybe the cable was faulty, so I spent money buying a cable, a genuine Sony one, but still had similar problems.

When I inserted a cartridge the picture gets even worse!

I think the fault is a power suppply problem. When I have the time I intend changing some components on the power supply, or even hooking up an external one to do the job.

I think this may solve the problem, has anyone else had similar problems?