Problems with Tecnobytes slotexpander

Paladin (749)

21-02-2018, 21:02

Recently I purchased the Slotexpander made by Tecnobytes. Ordered this through Mika Tahti, it costed me quite some money 235,= euro ( incl shipment ).
Yes, it is a high price, but I was willing to pay the price for a good product.

But is it an actual good product? No not all. Even worse, it's actually a disaster, that is able to harm your MSX computer.

First off, package arrived and opened during a stream on Twitch, it was well-packaged and also we hooked it up right away to the MSX, to see it in action.
A thing we noticed quite fast, every sound device's volume was decreased by 50%.

So panasoft fmpac, got replaced, by MCWF FM-Pac, and cables got ordered for the Philips Music Module, to provide output using external cables, for the stream.
Even with the other FM-Pac PSG was overruling the other sound chips, but this time much less, it wasn't satisfying, but it was a workable solution.

After using this expander for 3,5 day it even got worse. My Philips NMS8245 MSX2, got damaged.
Typical it just happens to be after using the slotexpander for a few days.
Response from "Tecnobytes" :
"There is no way for the Expander Slot to perform any kind of incorrect function on any MSX MACHINE that causes this type of problem. He's protected. Or you used it improperly."

Used it improperly?? Seriously, that's the worse answer they could provide.

How was it all setup:

Memory mapper in top slot, slotexpander, in backslot.

Slotexpander, was filled up with Nowind, FM-Pac, and SCC, I left the Music Module out since I was awaiting the cables.
The slotexpander even had it's own powersupply hooked up. So improper usage is out of the question here.

What happened? Well, the harm that has been done, results in MSX-Audio as well for MSX-Music from the FMPac aren't being outputted over the TV no more.
Only PSG, and SCC, MSX-Audio external audio ouput does work btw.

This has also been tested without the slotexpander.
Tested the Music cartridges in a different MSX everything is working fine, so the cartridges are fortunately not broken.

So thanks to Tecnobytes we now have a slotexpander that's able to harm your MSX computers.

Why was this posted, since both parties refused to offer a workable solution, I decided to go public with the harm that's been done by their products.

Van Latok

msx guru (3927)

21-02-2018, 21:46

Of the 50 pins, is the pin that outputs sound the same on both fmpac and music module? And a different pin on scc?

Van Wierzbowsky

Guardian (3571)

21-02-2018, 21:55

I may be mistaken, but the loss of sound or decreased volume may originate from the incorrect -12v and +12v supply. Especially if the sound cartridges work ok in other MSXs, the slot expander might have got a problem with supplying the correct voltages to the 12v pins of its slots.

You mentioned that your MSX2 got damaged, but I didn't find the description of the damage in your post (or I overlooked it). So what exactly happened? This is a serious accusation you are making so you have to provide some solid facts.

Van Manuel

Ascended (19298)

21-02-2018, 21:55

There is only one pin on the MSX slot that receives sound from a cartridge (SOUNDIN).

Van Hydragon

Paladin (749)

21-02-2018, 22:04

Alexey wrote:

Well that my MSX got damaged is a fact. Since both FMPac as Philips Music Module are not providing audio output anymore over the tv after 3 days of using the expander.
These tests ( plugging in the cartridges, to check audio result ) are done with and without the expander.

Also tested the Music Module on a different machine, on which it was still working fine, so everything comes back to the MSX itself now. only PSG and SCC are being outputted, no more MSX Music and no more MSX Audio at all.

Another thing that has been noticed, if you put in the SCC ( i use myself a big old tv ) in the slotexpander and up the volume, you hear a high pitched sound when you boot the MSX, this isn't happening if you use that same SCC cartridge in the MSX itself.

Van Latok

msx guru (3927)

21-02-2018, 22:06

Manuel wrote:

There is only one pin on the MSX slot that receives sound from a cartridge (SOUNDIN).

So it's strange the SCC does seem to output sound on real MSX and the fmpac and musicmodule don't...

Van hamlet

Scribe (4105)

21-02-2018, 22:14

Hydragon, I understood you are angry about your damaged MSX and the comment Tecnobytes did about.
And indeed this is a very bad situation. But we are seeking tecnobytes statement and the community is looking for a solution. Until I'd like to change the title from 'Tecnobytes slotexpander will harm your MSX!' to 'Problems with Tecnobytes slotexpander' I really hope you agree. Thanks.

Van msxholder

Champion (399)

21-02-2018, 22:16

Service manual from 8245 C29 and or c30 defective??

Van Colemu

Hero (542)

21-02-2018, 22:29

My Tecnobytes slot expander causes quite bad interference in video output on my TR.
I therefore no longer use it, and fell back on my Supersoniqs Modulon (which works perfectly).

Quite disappointing considering the great quality of previous purchases from Tecnobytes.

Van zett

Hero (608)

21-02-2018, 23:17

are there schematic drawings of the technobite version? becourse its directed from the original.

Van Philip

Champion (380)

21-02-2018, 23:43

Some weeks ago I had a similar problem, no fmpak and Toshiba hx-mu900 sound on me 8245.
Scc and psg did work. I checked the voltages and there was no -12v.
Turned out the 8245 has a 2 fuses in the power supply, and one is just for -12v... So you might want to check the fuse.It's the one closest to the transformer.