Hallo gentlemen

ch habe einen Portoroz TM Ausfall TM . die Stücke sind auf dem Brett , aber der Computer sie nicht spüren . Es kann selbst spielen, aber übernimmt keine Sensoreingang . Ich habe die Anschlüsse überprüft . Ich habe die EPROM ersetzt , ich habe ein paar Anschlüsse gereinigt.

Aber weiter zu gehen, brauche ich ein Tech- Blatt , mir zu sagen , die Dioden , Transistoren, ICs Werte und Spezifikationen.

bitte mich an die Quelle leiten , muss es jemand sein, der diese Informationen kennt.

Vielen Dank

I have a failure TM portorose TM. the pieces are on the board but the computer does not sense them. It can play itself but accepts no sensor input. I have checked the connectors. i have replaced the EPROM, I have cleaned a few connectors.

But to go further I need a tech sheet to tell me the diodes , transistors, ICs values and specifications.

please direct me to the source , there must be someone who knows this information.

Thank you
Queegmeister

Hallo Queegmeister,

maybe you could post some pics from your TM Portorose insides, so the electronic savvy guys here would have a chance to understand what could be wrong with your TM.

Kind Regards
Theo

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Meine Schachfotos
Schachcomputer

If the TM plays itself (without recognizing the pieces) it's unlikely that CPU, RAM or Eprom is broken.

My guess: it's a problem in connection (flex cable) between CPU PCB and PCB with the reeds. An electronics engineer should be able to fix this.

Cheers,
Andreas

I am trying to get a schematic of the PCB so I can fix it. The flex cable seems fine. I had not moved the board for a while and it worked the last time used. Where can another ribbon be found ? or are you suggesting we can fix the existing cable ? Even if its just the connection problem, eventually I will need a schematic. Something else will go bad. I have to believe that a schematic exists somewhere in the world. And that I can get it.

Thank you
Queeg

here are some pics in a zipNew Folder.zip

please let me know if these pictures are good enough this link is the key problem he can play himself but does not see my pieces
https://postimg.org/image/h9g09ihpz/

thank you gentlemen
queeg

Phoenix Chess has advised the error is

The problem is in reading the reeds. This curcuitry is driven by two chips.

If anyone can tell me where these chips are , which ones , then a repair is possible

If I can get the ancient IC , which I assume is needed

Thank you

Mike,

The reeds will be read by the chip marked with 74HC244 near the connector, it is a 8 octal buffer, which allows the 68020 proc to read the 8 reeds. As we can see the leds on the board flashing the two chips 74HC374 are working. One of them is a octal flip flop who clocks in 8 lines to the board (leds and reeds) and the other is a octal flipflop who clocks in the other side of the leds.

In order to read the reeds or show the leds (8 at a time) the octal flip flop is set who clocks in 8 lines to the board (leds and reeds) is clocked and then enabled through OE. In order to set the octal flip flop who clocks in the other side of the leds should have the OE disabled. It is a simple matrix led/reed board.

Anyway, the system is working, but does not read the reeds. So the first defective thing could be this chip. Replace it with an new 74hHC244. And check the system. If it is socketed this is easy. If not, your repair man can check if the chip is getting OE signals to 1OE and 2OE. If this chip gets the signals, he should check if the 8 signals are connected to the reeds (matrix wise). If the chip is faulty solder it out and replace… But you can check if the chip is working during power on. Or your repair man can.

If the 74HC244 is working,but does not receive the 1OE and 2OE signals, the next chip to check is the 3to 8 decoder marked 74HC138. This must be the address decoder. If I am guessing correctly, three of the outputs are connected to the mentioned 74HC244 chip and the two 74hc374 (to the CP and OE signals). Maybe some inverters are in between. I would suspect this chip to replace next, however,as the leds are working only the signal from this chip to 1OE and 2OE for the74HC244 could be at fault. PS, I checked, pin 9 from the 74hc138 is driving the 74hc244. If pin 9 is switched high the 74hc244 puts the reeds (8 at a time) on the data bus for the 68c020..

My top suspect is the74hc244, and secondly the 74hc138. But I am for 95% sure it is the 74hc244.
Lastly the problem could reside in the led/reed board or the cable.


Greets and maybe a US$ 5 repair...

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Grusse,
Ruud Martin